1lab.scalda.nl/doc/EVPW6.doc · Web viewSeparation vessel 250 ml Round bottom vessel 250 ml Laboratory glass 3.2 Materials and their safety codes Name CAS no. Dichloromethane 75-09-2

Praktijkvoorschriften pw6 1

Praktijkvoorschriften pw6Determination of zinc in multivitamin tablet using atomicabsorption spectrophotometry

Determination of ethanol in beer using GC method internal standard

Determination of phosphate in diet Coca Cola using visible spectrophotometry

Determination of caffeine in diet Coca Cola using HPLC

Determination of fat content of coffee cream using extraction

Determination of citric acid in Hubba-Bubba chewing gum using acid-base titration

Determination of total acid content of fruit juice using acidbase titration

Determination of phosphoric acid in diet Coca Colausing potentiometry

Determination of sugar using polarimetry

Het onderdeel calculation is bij de voorschriften weggelatenDit wordt behandeld in de theorielessen


Determination of zinc in multivitamin tablet using atomicabsorption spectrophotometry

1 ScopeThe method is suitable to determine the zinc content of effervescent multivitamin tablets (max 8 mgtablet) that usually contain several metal ions and other substances (sugar sweeteners etc) as well2 PrincipleThe tablets under investigation are dissolved in water The zinc content ismeasured by atomic absorption spectrometer (AAS) after adding hydrochloricacid to the solution A calibration curve is made by using zinc solutions withknown concentration and then the zinc concentration of the sample solution can be determined by using the calibration curve The zinc content of the sample (effervescent tablets) is calculated from the concentration of the sample solution3 Apparatus31 Equipment311 Instruments

bull Calibrated analytical balancebull Atomic absorption spectrometer (Type eg SHIMADZU AA-680)

312 Glasswarebull 100 mL volumetric flasks (calibrated as Class lsquoArsquo)bull 200 mL volumetric flasks (calibrated as Class lsquoArsquo)bull 1000 mL cylinderbull 5 mL pipette (calibrated as lsquoClass Arsquo)bull 10 mL pipette (calibrated as lsquoClass Arsquo)bull 10 mL burettebull 1 mL syringebull 200 mL beaker (tall)bull Weighing funnelsbull Funnelsbull Beakerbull Watch-glass

313 Other equipmentbull Filtering standbull Filtering ring

32 Materials and their CAS numbers see Table 1

Table 1 Materials and their CAS numbersName CAS

Zinc oxide 1314-13-2 (egFluka zinc oxide pss p a)Concentrated hydrochloric acid(egFluka hydrochloric acid fuming pss p a)7647-01-0

33 Reagent solutions331 ZnCl2 standard solution (1 mg mL Zn2+ content)

Weigh 01245 g of ZnO on an analytical balance as precisely as possible and dissolve it in 5 mL concentrated hydrochloric acid Wash this solution into a 100 mL volumetric flask using distilled (or ion exchanged) water fill it to the mark and mix well

Note Working with concentrated hydrochloric acid is very dangerousThe operator must know and obey the safety rules332 ZnCl2 solution (005 mg mL Zn2+ content)


This is made with a 20 times dilution of the ZnCl2 standard solution pipette 5 mL of the ZnCl2 standard solution wash it into a 100 mL volumetric flask using distilled water fill it to the mark and mix well

333 Hydrochloric acid solution (002 mol L)About 1 mL concentrated hydrochloric acid (using a 1 mL syringe) is diluted to 600 mL in a cylinder with distilled water and mixed well

4 Preparation41 Preparation of apparatus411 Calibration of the analytical balance

Calibrate the analytical balance according to the instruction manual412 Calibration of the volumetric flasks and pipettes

See on a separate part of the web site42 Preparation of sample

Weigh each of the tablets in the box on an analytical balance and calculate the average mass (m) Put one of the tablets (make a note about its mass) into a tall 200 mL beaker fill the beaker up to 13 of its height with distilled water cover it with a watch-glass and wait until it is completely dissolved Wash all the material spattered on the watch-glass into the solution with distilled water mix the solution and wash it into a 200 mL volumetric flask Fill the flask to the mark with distilled water and mix wellIf the solution is completely clear and sediment-free pipette 10 mL of it into a 100 mL volumetric flask and then fill it up to the mark with 002 molL hydrochloric acid (This way we model the effect of the hydrochloric acid found in the stomach) In this case the preparation of the sample is finished If the solution is not completely clear and sediment-free shake the contents of the 200 mL volumetric flask thoroughly and pour about half of the solution into a 3 200 mL beaker put it onto a magnetic stirrer While stirring pipette 10 mL of the solution into a 100 mL volumetric flask fill it up to the mark with 002 molL hydrochloric acid and mix well (Thus we model the case when the consumer drinks the stirred solution)Let the remaining solution settle in the 200 mL beaker Carefully pipette 10 mL of the solution into a 100 mL volumetric flask (so that the sediment is not stirred up) fill it up to the sign with 002 molL hydrochloric acid and mix well the solution (This way we model the case when the consumer drinks the settled solution without its sediment)

43 Preparation of the series of the calibrating solutionsThis is done by diluting the 005 mgmL ZnCl2 solution so that we have a series of calibrating solutions with the mass concentration of 1 2 3 and 4 mgL Zn2+ respectively This means that using a 10 mL burette we have to measure 2 4 6 and 8 mL parts of the 005 mg cm-3 ZnCl2 solution into 100 mL volumetric flasks fill them up to the mark with 002 molL hydrochloric acid mixing well

5 ProcedureThe atomic absorption spectrometer is switched on and the zinc lamp is adjusted if necessary After the warming up time and the self-test of the instrument the necessary parameters (eg lamp number lamp current wavelength slit measuring method integration time concentrations of the calibration solutions etc) are set and then the measurement is startedAtomise (vaporize) the 002 molL hydrochloric acid solution as BLANK thecalibrating solutions as STANDARDs and then (once the calibration is finished)the UNKNOWN solution(s) (the one with sediment and the other without


sediment in the latter case of the point 42) As well the absorbance theinstrument gives the measured mass concentration (ρ [mgL])

7 Expression of resultsThe results of the measurements are given in [mg Zn2+tablet] units eg 36 mg Zn2+tablet


QuestionsChoose the correct answer1 The temperature of the acetylene ndash air flame is

a) 1500 - 2000 Kb) 2000 - 2500 Kc) 2500 - 3000 Kd) 3000 - 3500 K

2 How does the solution under investigation get into the flamea) A pump presses itb) Its flow is helped by gravityc) The gases feeding the flame suck itd) An auxiliary gas sucks it

3 The lamp used in atomic absorption spectrometers is aa) tungsten bulbb) deuterium lampc) mercury vapour lampd) hollow cathode lamp

4 The wavelength of the absorbed lighta) depends on the type of flameb) is characteristic of the quality of the substance under investigationc) is characteristic of the quantity of the substance under investigationd) does not depend on the quality of the substance under investigation

5 The absorbancea) depends only on the concentrationb) is proportional to the concentrationc) is inversely proportional to the concentrationd) does not depend on the concentration

Choose the answer that is incorrect6 Among the following events which is the one that is not caused by the heat of the flame

a) The evaporation to dryness of the solutionb) The evaporation of the substancec) The atomisationd) The excitations of the atoms

7 Choose the statement that is not true Using metal halogenide compounds in atomic absorption spectrometry is advantageous because

a) they are not corrosive substancesb) they usually dissolve easilyc) they evaporate easilyd) they can be easily atomised

8 Choose the incorrect statement It is not good if large drops get into theflame because

a) the flame cools downb) the evaporation and the atomisation will be unevenc) too many atoms get into the flamed) the substance is atomised to an unsatisfactory extent


Determination of ethanol in beer using GCmethod internal standard1 ScopeThe goal of this analytical procedure is to determine the percentage ethanol in beer and other beverages Dutch normal beer must contain no more than 5 vol ethanol

2 PrincipleWe add the same amount of 1-propanol to each solution to be measured Theanalyte is injected into a GC with polar column The height of two peaks for ethanol and propanol is measured By calculating the ratio (height ethanol height propanol) the result does not depend on the injection volume or any air bubbles present in the needle during injection Comparing the ratio with a calibration of a known ethanol concentration will give the exact amount of ethanol in the sample

3 Apparatus31 Equipment311 Instruments

Gas chromatograph with polar column Carbowax or Tenax Nitrogencarrier gas and FID detector (capillary column could also be used)

312 Glassware and other equipment6x25 mL volumetric flasks (calibrated as Class lsquoArsquo)pipettesGC injection syringe 0-5 micro litre

32 Materials and their safety codesName No Remarksethanol 64-17-5 absolute or 100 ethanol is not recommended

95 vol is satisfactory1-propanol 71-23-8 99 vol is satisfactory free of other alkanolesacetone 67-64-1

4 PreparationPrepare the gas chromatograph as described in the user manual Make sure that temperatures of oven injector and detector are stabilisedColumn 16 metre Carbowax 20 M by GC- use

Carrier gas Nitrogen 20 mL per minuteOven 100 oCDetector FID 150 oCInjector 150 oCRange 10-9

Attenuation 1-1024 to give max peak heightsNote Use the attenuator to give the largest peaks possible This will give better measurements of the peak heights on paper Since both peaks will be equally larger or smaller at different degrees of attenuation this will have no effect on the ratio


5ProcedurePreparation of calibration curve

Take 4 volumetric flasks of 25 mL and pipette into each flask 1 mL 1-propanolPut respectively 05 1 2 and 3 mL ethanol in the flasks Fill up with distilled water and mix well

Preparation of the beer sampleDe-gas 30 cL Heineken beer (in can or small flask) by adding a few drops of acetone Pipette 2x 20 mL into two volumetric flasks of 25 mLAdd 1 mL 1-propanol to each flask and fill up with distilled waterInject 1 μL of the calibration solutions from low to high ethanol volMeasure the height of both peaksInject 1 μL of the duplo sample Heineken BeerMeasure the height of both peaks

6 Expression of resultsThe results will be given in the by volume (vv) of beer sampleA conclusion should be drawn whether the average of the duplo does not exceed 5 vol

7 PrecisionThe precision of this method is 10 based on 20 student results


8 Questions

1The main goals of gas chromatography are to

I Separation of mixtures into their componentsII quantative determination of components

a Normally first I followed by IIb Normally II first followed by Ic Its doesnrsquot matter in what order III or IIId I and II both are not main goals

2For good separation the injector must be heated

a For better gas flowb To evaporate the samplec To remove any fluctuations in temperatured For warmer components

3When the sample contains polar components thena A polar stationary phase will lead to better separationb A polar stationary phase will decrease retention timesc A non-polar stationary phase will increase retention timesd Polar or non-polar it doesnrsquot make any difference

4The injector temperature and detector temperature must be set a Lower than the column temperature to avoid condensationb Equal in temperature to the columnc Higher than the column temperature to avoid condensationd to any temperature lower of higher

5I Using a FID any water in the sample will cause an extra peakII Using a catharometer (TCD) will give a air-peak from any air in the needle

a I is right but II is wrongb II is right and II is wrongc Both I and II are rightd Both I and II are wrong

6A sample containing both ethanol and 1-butanol is analysed on a polar column

a Ethanol will come out firstb 1-butanol will come out firstc They will come out at the same timed It cannot be predicted

7The use of the internal standard method is often used because


a Standards for chromatography are cheapb It will save the amount of used chemicalsc It doesnrsquot make any difference when injecting less or more sampled It is rarely used because it is a bad method

8When drawing the calibration graph with horizontally concentration ethanol and vertically is set to the quotient of areas

a buthanol ethanolb area ethanolc it doesnrsquot make any difference all are fined ethanol butanol

9A sample liquid is analysed by GC using internal standard The measurement is performed using 10 mL liquid and put it into a volumetric flask of 25 mL adding the internal standard and filling up to the mark From this solution a chromatogram is used to determine the ethanol concentration In the calibration graph the student reads 500 vol ethanol The original liquid will contain

a 200 vol b 500 vol c 100 vol d 125 vol

10When the ethanol used for the standard is common denaturised ethanol this means that

a The ethanol is produced chemically and not in a natural wayb Men cannot drink it because butanol is addedc Extra methanol is added to make it undrinkabled It is a brand name like Merck or Sigma

11When denaturised ethanol is used an extra peak might appeara This extra peak is due to air bubblesb This is caused by some methanol in the ethanolc This means the student has not injected rapidly enoughd This is due to a electrical failure

12The best injection technique is to Fill the syringe with the sample solution and press it out Repeat this three times to clean the inside of the syringeThen

a Fill the syringe with sample clean the needle suck some air inbring slowly into the injector press rapidlyb Fill the syringe with sample suck some air in bring in rapidly and inject slowlyc Fill the syringe with sample bring in the needle slowly and inject rapidly


d Fill the syringe with sample bring in the needle rapidly and inject slowly

13When a peak is drawn on paper using the attenuator on 32 (actually 2^32) the peak is to small To get the peak twice as large the next injection should be taken at

a 2^64b 2^32c 2^16d neither of the above is correct

14When using the internal standard method a student injects by accident 50 more sample so instead of 2 micro litre he injects 3 micro litrea This effects the ethanol and butanol area so it will be a bad analysesb This effects the ethanol and butanol heights so it will be a bad analysesc This doesnrsquot effect the analyses since the quotient ethanolbutanol will stay the samed This doesnrsquot effect the analyses as long a the peaks stay separated

15I To give acceptable results the peaks must be clearly separated (no overlap) II When peaks are symmetrical and thin the peak heights can be used as well as peak areas

a I is true but II is notb II is true but I is notc Both I and II are trued Both I and II are false

16

I When operating the gas chromatograph the gas flow should be optimisedfor better separationII When the separations of the alcohols is performed on a longer columnthe separation will be worse and retention times will be longer

a I is true and II is falseb II is true and I is falsec Both I and II are trued Both I and II are false


Determination of phosphate in diet Coca Cola usingvisible spectrophotometry

1 ScopeThis method is used for the determination of phosphate in diet Coca Cola

2 PrinciplePhosphate is an example of phosphorus derivatives that most of us use everyday of our lives Phosphates are of great importance they are used to make animal skeletons ie bone and teeth they are used to make ribonucleic acids the genetic code they are used as pH buffers both in body fluids such as blood and in the laboratory They are important ingredients in fertilizer Refreshing cola drinks contain phosphoric acid It adds tartness to their flavourPhosphate ions with iron(II) and molybdate ions form a blue coloured complex absorbing around 750 nmThe phosphate content in the diet Coca Cola is determined by interpolation from a calibration curve


Analytical balance accuracy = 01 mgSpectrophotometer (VIS)1 cm glass cuvetteApparatus for degassing and filtering

312 Glassware and other equipmentVolumetric flasks (class A)Transfer or one-bulb pipettesGraduated cylinders

32 Materials

Name Grade CAS-NoAmmonium heptamolybdate tetrahydrate reagent 12054-85-2Ammonium iron(II) sulphate hexahydrate reagent 7783-85-9Sulphuric acid reagent 7664-93-9 Potassium dihydrogen phosphate pa 7778-77-033 Reagent solutions331 10 g100 mL ammonium heptamolybdate tetrahydrate in 4 molLsulphuric acid332 Dissolve 5 g ammonium iron(II) sulphate hexahydrate in 8 mL1 molL sulphuric acid dilute the solution to 100 mL333 Reagent R one (1) volume of ammonium heptamolybdatesolution(331) and nine (9) volumes of iron(II) solution (332)This solution should be freshly prepared334 Potassium dihydrogen phosphate (KH2PO4) pa

4 Preparation41 Preparation of apparatus


Switch on the spectrophotometer42 Preparation of sampleDegass the diet Coca Cola sample by shaking and filteringboiling or use an ultrasonic bath

5 Procedure51 Preparation of the calibration curve and sampleProcess the sample and the calibration curve solutions simultaneouslyCalibration curve

Prepare a standard solution using potassium dihydrogenphosphate (KH2PO4) paThe calibration curve solutions should contain 0 ndash 10 mgL phosphate (PO4

3- ) Use 50 mL volumetric flasksDo not make up to the mark yet

Sample preparationThe Coca Cola sample contains approximately 500 mgL phosphate (PO4

3-)Transfer the correct amount of the degassed Coca Cola sample in a 50 mL volumetric flask The absorption of the sample should be in the midpoint of the calibration curveDo not make up to the mark yet

Add to all the volumetric flasks 10 mL reagent R (333) then make up to the mark with distilled water and mix well

52 MeasurementMeasure the absorbance of the sample and the solutions of the calibration curve with the spectrophotometer using a wavelength of 750 nm

6 Quality requirementsAll glassware must be rinsed well some detergents contain phosphate

7Expression of resultsThe results will be given in mgL-1 PO4

3-

8PrecisionThe standard deviation of the results of 10 students is 28


9Questions1 3000 mg potassium dihydrogenphosphate is dissolved in 5000 mL2500 mL is transferred in a 1000 mL volumetric flaskThe concentration of the potassium dihydrogenphosphate is then

a 15 mgLb 150 mgLc 75 mgLd 125 mgL

2 10971 g ammonium iron(II) sulphate hexahydrate is dissolved in 2500 mLOf this solution 1000 mL is transferred to a 2500 mL volumetric flaskFrom this volumetric flask 500 mL is transferred to a 500 mL volumetricflaskThe concentration of the iron(II) ions is then


3 How much potassium dihydrogen phosphate do you weigh for a 10000 mLstandard solution when a dilution of 500 mL of this standard solution in1000 mL has a concentration of 10 mgL phosphor

a 879 mgb 934 mgc 6805 mgd 879 mg

4 If the absorption of a solution is 05 the transmission is a 316b 170c 316d 500



1 ScopeThis method is used for the determination of caffeine in diet Coca ColaIt is also applicable for the determination of caffeine in other beverages

2 PrincipleCaffeine (137-trimethylxanthine) is a stimulant that is commonly found in many foods and drinks that we consume Caffeine has a mildly addictive effect on the body it is therefore interesting to know exactly how much caffeine is in certain beveragesOne way to analyse caffeine content in beverages is by using high-performance liquid chromatography (HPLC)Caffeine an alkaloid from the group of xanthine derivates can be determined with HPLC The cola sample is after dilution and degassing suitable for HPLC analysis on a C-18 reversed phase columnIn this experiment a calibration curve is used the peak height or the peak area is measured and plotted against the concentration of caffeine in the standard solutionsThe caffeine content is determined from the plot


Analytical balance accuracy = 01 mgHPLC with a C-18 reversed phase column like Hypersil C18 Zorbax C18 250x4 mmparticle size 3-5 μma 20 L sample loopand UV-detector 254 nmIntegrator or recorderApparatus for degassing and filtering

312 Glassware and other equipment100 mL and 1000 mL volumetric flasks (class A)transfer or one-bulb pipettes (5 10 20 and 50 mL)045 m porosity syringe filter (nylon PVDF)

32 Materials

Name Grade CAS-NoCaffeine Reagent 58-08-2Methanol HPLC 67-56-1Acetic acid HPLC 64-19-7Water HPLC 7732-18-5

33 Reagent solutions331 500 mgL caffeine solution

Weigh out accurately about 500 mg reagent grade caffeine anddissolve in eluent

332 Eluentmethanol = 10 in acetic acid 1 molL-1


4Preparation41 Preparation of apparatus

HPLCFlow eluent 1 mLmin-1

UV detector detection range to be determined42 Preparation of sampleDegass the diet Coca Cola sample by shaking and filtering

5 ProcedureSample preparation

Transfer 5000 mL of the degassed Coca Cola sample into a 100 mL volumetric flaskMake up to the mark with distilled water and mix well

Preparation of the calibration curveTransfer 500 1000 and 2000 mL of the standard caffeine solutioninto 100 mL volumetric flasksMake up to the mark with distilled water and mix well

MeasurementUse 045 m syringe filters (nylon PVDF) to filter the solutions before injection Record the chromatograms of the calibration curve solutions and the sample solution

6Expression of resultsThe results will be given in mgL-1



8Questions

1 An non-polar component in a sample is separated on a reversed-phasecolumn The mobile phase is 30 (mm) acetone in petroleum etherIncreasing the percentage of acetone in the mobile phase will

a lengthen the retention time of the non-polar componentb shorten the retention time of the non-polar componentc not change the retention time of the non-polar component

2 Predict the order of elution for a normal-phase separation a benzene n-hexanol n-hexaneb n-hexanol benzene n-hexanec n-hexane benzene n-hexanol

3 For a HPLC separation the distribution constant for component A is 35for B 15 and for C 25The component that will first pass at the end of the column is a Ab Bc C

4 For the HPLC determination of vitamin C in a soft drink we have thefollowing resultsCalibration results Concentration (gL-1) AreaVitamin C 125 632Saccharin 144 304Sample preparation 1000 mg saccharin is added to 250 mL soft drinkthe total volume is made up to 1000 mLSample results Area

Vitamin C 466Saccharin 195

The concentration vitamin C in the soft drink is a 10 gL-1

b 399 gL-1

c 368 gL-1

LiteratureSkoogHollerNieman Principles of Instrumental Analysis 5th

editionSaunders College PublishingChapter 28 High performance Liquid ChromatographyInternet page ugrad - wwwcscoloradoedupopfactshtml


Determination of fat content of coffee creamusing extraction

1 ScopeThe method is suitable for the extraction and quantitative determination of fat in coffee creamers using dichloromethane and methanol It is in accordance with the method by Bligh and Dyer (1959)

2 Principle The extraction of fat from several (food) products under mild conditions


Turrax (Ultra turrax )CentrifugeRotary evaporator

312 Glassware and their equipmentFolding filters (SampS Oslash 150 mm 595frac12)Separation vessel 250 mlRound bottom vessel 250 mlLaboratory glass

32 Materials and their safety codesName CAS no

Dichloromethane 75-09-2Methanol 67-56-1Potassium chloride 7447-40-7Sodium sulphate 7757-82-6

4 ProcedureCheck beforehand that all equipment meets current regulationsWeigh in a 250 ml cup a min of 10 g and max of 50 g of the sample(depending on the expected fat content) Add 50 ml 10 potassium chloride and mixAdd successively 100 ml dichloromethane and 50 ml methanolHomogenise with the turrax for 3 minutes at appr12000 rpmDirectly after homogenisation pour the mixture into a separation vessel and wait for a visible separation Collect the dichloromethane (lower layer) in a 250 ml cup add some sodium sulphate and stirFilter the dichloromethane over a folding filter into a weighed round bottom vessel of 250 ml Evaporate the dichloromethane in a rotor evaporator at 45 degC discard the dichloromethane from the collection vessel and extend the evaporation for 30 minutes Weigh the vessel with the fat (m3 g)Determine the oil extracted and fat content of the sample by gravimetry

RemarksIf no separation occurs in the separation vessel pour the mixture into somecentrifuge vessels Centrifuge for 5 minutes at 1500 rpm Separate the upper layer and filter the lower layer over a folding filter into a cup Add some sodium sulphate and filter the solution into a round bottom vessel


Proceed with evaporating the dichloromethane as described above

5 Expression of resultsThe results will be given in mass

6 PrecisionThe relative standard deviation of the results of 4 students is 10


7 Questions1 Which solvents are non-polar

a cyclohexaneb methanolc acetonitriled tetrahydrofuran

2 The density of dichloromethane isa equalb higherc lowerthan water

3 Fat is aa di-ester of a fatty acid and glycerolb di-ester of a fatty acid and glycolc tri ester of an unsaturated fatty acid and glycerold tri ester of a saturated fatty acid and glycerol


Determination of citric acid in Hubba-Bubba chewing gum usingacid-base titration

1 ScopeThe aim of this analytical procedure is to determine the citric acid content in Hubba Bubba bubble gum This bubble gum is available in the UK and most parts of Europe It is manufactured by Wrigley in Plymouth UK The method described here is based on an analytical procedure used by the Wrigley company in their Plymouth laboratories For more information about Hubba Bubba products see httpwwwwrigleycoukHubbaBubbaIndexcfm

2 PrincipleThe determination is based on an acidbase reaction between the citric acid in the bubble gum and standard sodium hydroxide The citric acid content of the bubble gum can be calculated from titration results

3 Apparatus

31 Equipment1048707 kitchen pastry roller1048707 250 cm3 conical flask1048707 250 cm3 graduated flask1048707 100 cm3 graduated flask1048707 magnetic stirrer and follower1048707 10 cm3 burette (reading to nearest 002 cm3)1048707 top pan analytical balance

32 Materials and their CAS numbers

Orange flavoured Hubba Bubba was used (lsquoAwesome Orange Its an orange attack Let your mouth go wild with this awesome flavourrsquo)1048707 Sodium hydroxide 1310-73-21048707 Phenolphthalein 77-09-8

33 Reagent solutions1048707 Standard 0100 molL sodium hydroxide If this is not available dissolve1000 g of sodium hydroxide in about 100 mL of pure water Wash carefully to a250 mL graduated flask and make up to the graduation mark Homogenise thesolution Standardise by titration with 0100 molL hydrochloric acid itselfstandardised against solid potassium hydrogencarbonate1048707 Phenolphthalein indicator Weigh out 020 g of phenolphthalein and dissolve inabout 50 mL of methanol Transfer solution to a 100 mL graduated flask andmake up to the graduation mark with methanol and homogenise the solution

4 Procedure1048707 Take one orange flavoured Hubba Bubba bubble gum piece unwrap it and place onto a wood block1048707 With a lsquokitchen rolling pinrsquo roll the bubble gum into a very thin strip approximately160 x 30 x 05 mm1048707 Cut the thin strip into small pieces about the size of long grain rice1048707 Weigh out 100 g of orange flavour Hubba Bubba bubble gum bits


1048707 Add to 100 mL of pure water contained in a 250 mL conical flask Add amagnetic follower and stopper1048707 Stir vigorously for 30 minutes making sure bubble gum bits donrsquot lump together1048707 Add 05 mL of phenolphthalein indicator and titrate with 01 mol dm-3 sodiumhydroxide contained in a 10 mL burette End point is pink1048707 Repeat twice more and average all three results

5 Expression of resultsGive the mass of citric acid monohydrate in Hubba Bubba bubble gum in percentage by mass (mass of citric acid monohydrate in 100 g of bubble gum)The manufacturerrsquos allowed range is 19 ndash 21 percentage by mass


Determination of citric acid in Hubba-Bubba chewing gum usingacid-base titration Questions

1 Citric acid is a tribasic acid What is the correct formula for citric acidmonohydrate

a CH2COOHCH(OH)CH2COOHb CH2COOHCH(OH)CH2COOHH2Oc CH2COOHC(OH)(COOH)CH2COOHH2Od CH2COOHCH2CH2COOHH2O

2 In what mole ratio do sodium hydroxide and citric acid monohydrate reacta 11b 21c 31d 41

3 In the reaction between sodium hydroxide solution and citric acid solution which pair are the spectator ions (ie ions which do not change during the reaction)a sodium ions and hydroxide ionsb sodium ions and hydrogen ionsc sodium ions and citrate ionsd hydrogen ions and hydroxide ions

4 25 mL of sodium hydroxide required 238 mL of 0108 molL hydrochloricacid What is the concentration of the alkali (in molL)a 0094b 0099c 0103d 0113

5 The calculation says ldquoUsing the following to calculate the percentage by mass of citric acid monohydrate in the Hubba Bubba bubble gumEach cubic centimetre of 01 molL sodium hydroxide is equivalent to 70 mg of citric acid monohydraterdquoExplain how this statement is obtained by answering these questions

a How many moles of sodium hydroxide are there in 1 mL of 01 molmL

sodium hydroxide solutionb In what mole ratio do citric acid and sodium hydroxide reactNote This is not the same as Question 2 but you can use that answerto help youc How many moles of citric acid will react with 1 mL of 01 molLsodium hydroxide solutiond What is the relative molar mass of citric acid monohydratee What mass of citric acid monohydrate will react with 1 mL of01 molL sodium hydroxide solution



1 ScopeThe total acid content in a sample of the fruit juice is determined by titration with a standardized sodium hydroxide solution The sample could be pineapple or grape fruit juice The acid content of fruit juices consists of organic acids as citric acid malic acid ascorbic acid (Vitamin C) and others We take all acids as if they were monobasic

2 PrincipleTotal acidity as the sum of monoprotic acids in a sample is determined bygradually adding sodium hydroxide solution to produce sodium salts of all fruit acids and waterHA(aq) + NaOH(aq) rarr NaA(aq) + H2OHA means all fruit acids NaA means sodium salts of all fruit acids

3 Apparatus31 Equipment- ordinary laboratory equipment32 Glassware- conical flask 250 mL 3 pieces- transfer pipette 20 mL 1 piece- burette 50 mL33 Materials and their safety codesName CAS No RS codesSodium hydroxidesolution c(NaOH)01 molL(fixanal)1310-73-2 R3638S26-37Phenolphthaleinindicator 2solution inmethanol77-09-8 R11-2325S 7-16-24

4 ProcedureMeasure 2000 mL of fruit juice Transfer it in a 250 mL conical flask Addroughly 75 mL distilled water and three drops of phenolphtalein indicator andtitrate the analyte with the sodium hydroxide solution to the permanent pinkish -red colourAttentions1 NaOH standard solution must be free of carbonate and the water used fordilutions must be boiled (and cooled) freshly before use to eliminate CO2content2 The measurement cannot be performed in strongly coloured or heavilyturbid fruit juices with pulp because the appearance of the pink colourcannot be seen properly

5 ResultSample c(acids) molL

Questions


1 Which of the laboratory glassware listed below is not used with the titration

a desiccatorb volumetric flaskc pipettesd burettes

2 The sodium hydroxide solution could be standardised witha hydrochloric acidb sodium hydrogen carbonatec standardised hydrochloric acid

3 FIXANAL is an ampoule of solutiona with the same concentration as sampleb with an accurate amount of titrant in ampoulec which must be standardised

4 Which of these acids is not an acid in fruit juicea acetic acidb citric acidc ascorbic acidd oxalic acid

5 During a titration a 2000 mL sample of fruit juice consumed 1232 mL ofsodium hydroxide solution of c(NaOH) = 01020 molLThe total acidity of sample is

a 0063 molLb 006283 molLc 006282 molL

6 The total acidity of a fruit juice is 0075 molL Calculate the consumptionof sodium hydroxide solution c(NaOH) = 00980 molL for a 2000 mL sampleThe correct answer isa 1531 mL b 1530 mL c 1535 mL



1 ScopeThe determination of phosphoric acid is based on the acid ndash base reaction ofphosphoric acid with sodium hydroxide All types of Coca ColaPepsi Cola contain phosphoric acid

2 PrincipleThe determination is based on the 1 1 mole reaction of phosphoric acid with sodium hydroxide The equation of the reaction isH3PO4 + OH- rarr H2PO4

- + H2O

3 Apparatus31 Equipment311 InstrumentsCalibrated analytical balance accuracy = 01 mgPotentiometer with glass and reference (AgAgClCl-) electrode312 Glassware and other equipmentbeaker 150 mLmagnetic stirrermotor driven burette or burette32 Materials and their safety codes

Name CAS noSodium hydroxide 1310-73-2Potassium hydrogen phthalate 877-24-7

32 Reagent solutionsStandard sodium hydroxide solution 004 molL

4 ProcedureSample preparationTake about 150 mL Coca Cola in a round bottomed flask of 250 mL equipped with a reflux condenser and heat the flask for 2 hours After cooling pipette 50 mL refluxed Coca Cola into a beaker and place a glass and a reference electrode in the solutionStir the mixture and titrate with 004 molL sodium hydroxide solution until the first equivalent point Titrate further to measure the S ndash shape Titrate with 01 mL increments around the equivalent point

Standardisation of sodium hydroxide solutionWeigh accurately about 100 mg potassium hydrogen phthalate on an analytical balance transfer it to a glass beaker and dissolve it in ca 50 ml water that has been boiled and allowed to cool Put a glass and reference electrode into the solution Stir the mixture and titrate with 004 molL sodium hydroxide solution Titrate with 01 mL increments around the equivalent point


5 Expression of resultsThe results will be given in mg H3PO4 L Coca Cola



7 Questions

1 50 mL Coca Cola which contains 950 mg H3PO4 L needs mLNaOH c(NaOH) = 004204 molL to reach the first equivalent point

a 3568b 1386c 9540d 1153

2 The pH in the equivalent point of the solution see question 1 is aboutKa (H3PO4H2PO4

- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99

3 The pH of Coca Cola is abouta 70b 32c 82d 102

4 Coca Cola must be refluxeda To remove CO2

b To remove caffeinec To remove low boiling acids



1 ScopeThe quality (sugar content) of commercial sugar products semi-white sugarsugar or white sugar extra-white sugar is determined using polarimetry Themethod is widely used in sugar trade Also the name saccharimetry is used when determining the quality of sugar We adopted it from the Institute for Public Health Ljubljana Slovenia

2 PrincipleIn polarimetry we make use of one of the phenomena occurred when light strikes a matter Here we observe the passage of polarized visible light through the solution of a substance (sugar) which rotates it Namely certain compounds mostly organic (notably those containing asymmetric carbon atoms) rotate the plane of polarized light The phenomenon is called optical rotation and such substances optically active compoundsMeasuring angle of rotation the concentration of a substance in a solution isdeterminedHow is a polarized light produced Most of the light we encounter every day is a chaotic mixture of light waves vibrating in all planes which are perpendicular to the direction of propagation Such a combination of light waves is known as unpolarized light If the light passes through certain materials (example calcite) which shows the phenomenon of double refraction (you see double line when you put a crystal on a line) two beams are leaving crystal and both are composed of polarized waves That means waves of light are now vibrating in only one plane Specially cut into a prism (Nicole prism) calcite functions as polarizer giving a polarized beam of light in a polarimeter Polarized beam travels through our solution with an optically active substance and is absorbed by analyser a second Nicole prism depending on the relative position of both prisms to each other and on the substance in betweenSo using a polarimeter we detect and measure a change in the plane ofpolarisation (rotation) induced by optical active samplesThe measured angle of rotation depends upon many variablesbull The type or nature of sample (example sugar solution)bull Concentration of the optical active componentsbull The length of the sample tubebull The wavelength of the light sourcebull Temperature of the sampleWe describe the nature of a sample by introducing the specific optical rotatorypower (or specific rotation) of a substance defined as

in SI units rad m2 kg-1 (Notice 2π rad = 360 0 (deg)where α is the angle of rotation in radγ is the mass concentration in kgm3and l is the length of the sample tube in m Specific rotation is determined at a specified temperature Θ (usually 20 oC) and a wavelength of light source (usually sodium lamp with its D line at 589 nm)Some substances rotate the light to the right (or clockwise) as viewed lookingtowards the light source we sign this rotation and α as + some to the left (oranticlockwise) signing α as -In practical measurements readings are taken at different units


α in o (deg)γ in gcm3l in dmand so

is usually tabulated in o cm3 g dmFor exampleSucrose (cane sugar) solution [ ] 200

= + 665 o dm at a concentration of 1 gcm3

3 Polarimetry of sugar solutionsPolarimetry is frequently used for determining the quality of sugar productsMeasurements are made by polarimeters or saccharimeters with the scale inangle degrees (o) and sugar degrees (oZ) Angle of rotation depends linearly on concentration of sugar in the solution other parameters (temperature lightsource length of the tube) being the sameSugar industry with its International Commission for Uniform Methods of Sugar Analysis (ICUMSA) introduces International Sugar Scale (ISS) in oZ units 10000 oZ units (sugar degrees) belong to Normal Sucrose Solution prepared from exactly 26000 g of sucrose dissolved in pure water to 100 cm3 At 20 oC and D sodium lamp rotation for this solution in a tube of 200 mm will be α = +34626 o (deg) The ISS is linearly divided ie a rotation of +17313 o (13 g100 cm3) equals to a reading of 5000 oZ The 0 oZ point in ISS is fixed by the indication given by the saccharimeter forpure waterNormal Sucrose Solution was used to calibrate and standardize polarimetricmethods and instruments Sugar solutions are not very stable and have to berenewed regularlyToday quartz control plates are used as a standard for the calibration ofpolarimeters More find in Techniques (Polarimetry)Interrelation between both scales is defined from a straight line (y = ax)equationoZ = 1000034626 o (deg) = 2889 o (deg)

4 Apparatus41 Saccharimeter graduated for the normal 26 g sucrose or polarimeter- The instrument should be installed in a room where the temperature ismaintained close to 20 0C Calibrate the instrument against standard quartzplates- Light source consisting of sodium vapour lampPrecision polarimeter tubes length 200 mm error does not exceeded plusmn 002 mm- Analytical balance accurate to within 01 mg- Individually calibrated 100 mL volumetric flask with stopper A flask with real capacity in the range 10000 plusmn 001 mL may be used without correctionFlask with a capacity outside those limits is used with an approximatecorrection to adjust the capacity to 100 mL- Water-bath controlled thermostatically to 20 plusmn 01 oC42 Materials in their safety codesName CAS No RS codesLead acetate trihydrate Pb(CH3COO)2 middot 3 H2OMr = 379396080-56-4 R61-33-48cedil48221-5053-62 S 531-45-60-61


Diethyl ether (C2H5)2O60-29-7 R6-12161920 S179151633These chemicals are needed to clarify the sugar solution which is notalways necessary43 Reagents- Clarification agent lead acetate solution (poisonous solution)Add 560 g of dry lead acetate trihydrate to about 1000 mL of freshly boiledwater Boil the mixture for 30 minutes and then leave it to stand overnightDecant the supernatant liquid and dilute with freshly boiled water to obtain asolution with density 125 gmL at 20 oCProtect this solution from a contact with the air- Diethyl ether (very inflammable)5 Procedure51 Preparation of sample solutionWeigh as quickly as possible 26 plusmn 0002 g of the sample and transfer itquantitatively into a 100 mL volumetric flask with approximately 60 mL ofwater- Dissolve by swirling but without heating- Where clarification is necessary add 05 mL of lead acetate reagent Mix thesolution by rotating the flask and wash the walls until the meniscus is about10 mm below the calibration mark- Place the flask in the water-bath controlled to 20 plusmn 001 oC until thetemperature of the sugar solution is constant- Eliminate any bubbles formed at the surface of the liquid with a drop ofdiethyl ether- Make up to volume with water- Stopper and mix thoroughly by inverting the flask at least three times- Allow to stand for five minutes52 Measurement of rotation- Maintain temperature 20 plusmn 02 0C for all subsequent operations- Obtain the zero correction of the apparatus- Filter the sample through the filter paper Discard the first 10 mL of thefiltrate Collect the next 50 mL of the filtrate- Wash the polarimeter tube by rinsing twice with the sample solution- Fill the tube carefully at 20 plusmn 01 oC with the sample solution- Remove all bubbles when sliding the end plate in position Place the tube inthe cradle of the instrument- Read the rotation to within 005 oZ or 002 angular degrees Repeat fourtimes Take the mean of the five readings6 Calculation61 The results are expressed in oZ to nearest 01 oZTo convert the angular degrees into degrees Z the following formula is used0Z = 2889 o (deg)Details are explained in Polarimetry under Techniques62 RepeatabilityThe difference between the two results of two determinations when carried out simultaneously or in rapid succession on the same sample by the same analyst under the same conditions and each representing the mean of five readings must not exceed 01 oZ


Questions

1 When light passes through a material and on leaving it vibrates in only one plane it is said to bea) polarizedb) reflectedc) refracted

2 Look at the two displayed formulae for glucose in its non-cyclic form Number the asymmetric C-atom which is typed in boldC-atoms are numbered from the aldehyde group ndashCHO on

CHO |H-C-OH |

HO-C-OH |H-C-OH | H-C-OH | CH2OH

D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose

Which of the following is the correct answera) 2b) 3c) 4d) 5

3 What is the mass concentration of sucrose in a solution at 20 oC if the length of the tube is 100 mm and the measured angle is +665 o a) 1 gmLb) 05 gmLc) 100 mgmL

4 What angle will be measured with the sample prepared in this experimentThe length of the polarimeter tube is 200 mma) 3458 o b) 173 o


c) 346 o

5 What is the name of the phenomenon that a substance exhibits and which is used to determine the concentration of that substance in a solutiona) refractionb) polarizationc) optical rotationd) absorption of light


Determination of zinc in multivitamin tablet using atomicabsorption spectrophotometry

1 ScopeThe method is suitable to determine the zinc content of effervescent multivitamin tablets (max 8 mgtablet) that usually contain several metal ions and other substances (sugar sweeteners etc) as well2 PrincipleThe tablets under investigation are dissolved in water The zinc content ismeasured by atomic absorption spectrometer (AAS) after adding hydrochloricacid to the solution A calibration curve is made by using zinc solutions withknown concentration and then the zinc concentration of the sample solution can be determined by using the calibration curve The zinc content of the sample (effervescent tablets) is calculated from the concentration of the sample solution3 Apparatus31 Equipment311 Instruments

bull Calibrated analytical balancebull Atomic absorption spectrometer (Type eg SHIMADZU AA-680)

312 Glasswarebull 100 mL volumetric flasks (calibrated as Class lsquoArsquo)bull 200 mL volumetric flasks (calibrated as Class lsquoArsquo)bull 1000 mL cylinderbull 5 mL pipette (calibrated as lsquoClass Arsquo)bull 10 mL pipette (calibrated as lsquoClass Arsquo)bull 10 mL burettebull 1 mL syringebull 200 mL beaker (tall)bull Weighing funnelsbull Funnelsbull Beakerbull Watch-glass

313 Other equipmentbull Filtering standbull Filtering ring

32 Materials and their CAS numbers see Table 1

Table 1 Materials and their CAS numbersName CAS

Zinc oxide 1314-13-2 (egFluka zinc oxide pss p a)Concentrated hydrochloric acid(egFluka hydrochloric acid fuming pss p a)7647-01-0

33 Reagent solutions331 ZnCl2 standard solution (1 mg mL Zn2+ content)

Weigh 01245 g of ZnO on an analytical balance as precisely as possible and dissolve it in 5 mL concentrated hydrochloric acid Wash this solution into a 100 mL volumetric flask using distilled (or ion exchanged) water fill it to the mark and mix well

Note Working with concentrated hydrochloric acid is very dangerousThe operator must know and obey the safety rules332 ZnCl2 solution (005 mg mL Zn2+ content)















a) 1500 - 2000 Kb) 2000 - 2500 Kc) 2500 - 3000 Kd) 3000 - 3500 K





























8 Questions































16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o
















a) 1500 - 2000 Kb) 2000 - 2500 Kc) 2500 - 3000 Kd) 3000 - 3500 K





























8 Questions































16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o







a) 1500 - 2000 Kb) 2000 - 2500 Kc) 2500 - 3000 Kd) 3000 - 3500 K





























8 Questions































16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o




a) 1500 - 2000 Kb) 2000 - 2500 Kc) 2500 - 3000 Kd) 3000 - 3500 K





























8 Questions































16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o




















8 Questions































16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o









8 Questions































16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o



8 Questions































16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o




















16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o









16










32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o









32 Materials














3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o













3-








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o








a 879 mgb 934 mgc 6805 mgd 879 mg









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o









32 Materials
















8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o













8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o



8Questions








b 399 gL-1

c 368 gL-1



























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o


























3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o















3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o











3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o






3 Apparatus


























Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o






















Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o



















Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o









Questions














- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o















- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o






- + H2O










7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o






7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o



7 Questions


a 3568b 1386c 9540d 1153


- ) = 10-213

Ka ( H2PO4-HPO42- )= 10-721

a 47b 70c 87d 99


















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o
















Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o











Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o





Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o



Questions



CHO |H-C-OH |


D(+)-glucose

CHO |

HO-C-OH |

H-C-OH |

HO-C-OH |

HO-C-OH | CH2OH

L(-)-glucose





c) 346 o



c) 346 o


Documents

1lab.scalda.nl/doc/EVPW6.doc · Web viewSeparation vessel 250 ml Round bottom vessel 250 ml Laboratory glass 3.2 Materials and their safety codes Name CAS no. Dichloromethane 75-09-2