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7/28/2019 ASC 0301z - 01- Chemistry, Matter, and Measurement - 54 slides.ppt
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INORGANIC
CHEMISTRY
ASC0301DR SITI SALWA ABD GANI
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Doa Menuntut Ilmu2
Ya Allah! Bukakanlah dan Tambahkanlah
Rahmat daripada KahazanahMu itu kepada
kami. Ya Tuhan, yang Maha Pengasih lagi
Maha Penyayang.
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COURSE TITLE: INORGANIC CHEMISTRY
COURSE CODE: ASC 0301
CREDIT: 2 + 1
LECTURE: 2 HOURS/WEEKLAB: 3 HOURS/2 WEEKS
TUTORIAL: 2 HOURS/2 WEEKS
ASSESSMENT
TEST 1: WEEK 5 15%
TEST 2: WEEK 10 20%
LAB REPORT: 15%
PRESENTATION (TUTORIAL): 10%
FINAL: 40%
REFERENCE BOOK:John W Moore, Conrad L Stanitski and Peter C Jurs, Chemistry -The Molecular Science, 4th. Ed., Brooks/Cole
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6/4/20134
COURSE TITLE: INORGANIC CHEMISTRY
COURSE CODE: ASC 0301
CREDIT: 2 + 1 (120 hrs)
Activities Hours
Lecture 2 hrs x 14 28
Revision 2 hrs x 14 28
Prelab report 1 hr x 7 7Laboratory 3 hrs x 7 21
Group discussion 2 hrs x 7 14
Tutorial presentation 2 hrs x 7 14
Test 1 preparation 2.5
Test 1 1.5
Test 2 preparation 2.5
Test 2 1.5
TOTAL 120
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Chemistry and Matter
6/4/20135
ChemistryClassification of Matter
AtomsMoleculesElements, substances and compoundsMixturesStates and Properties of Matter
Changes of matter
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Learning Outcomes
Classify samples of matter as pure substances,homogeneous mixtures, heterogeneousmixtures, compounds, and elements.
Recognize various form of matters.
Relate names to formulas and charges of simple ions.
Combine simple ions to write formulas and names ofsome ionic compounds.
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Chemistry
What is Science ?SCIENCE is the qualitative and quantitativestudy of nature and the natural laws
What is Chemistry ?CHEMISTRY is a science that examines thecomposition, properties and changes of matter.
What is Matter ?
Anything that have mass and occupy space,and can generally be perceived by our senses(color, texture, odor, hardness, and taste)
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Disciplines of Chemistry
Major traditional chemistry disciplines :
Chemistry Study of
Inorganic Non-carbon-containing substance (ASC0301)Physical Structure and changes of matter (ASC 0302)Organic Substance containing carbon (ASC 0303)Analytical Composition of matterBiochemistry Physical and chemical changes of
living organism
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6/4/20139MINGGU
PENGAJA-
RAN
ASC 0301
TOPIK
1Chemistry and Matter
Unit and Measurement
2The Structure of Atoms
Atomic Mass
3 Mole ConceptConcentrations of Solutions
4 Chemical Reactions
5 Stoichiometry of Reactions
6 Electromagnetic radiationAtomic Model
7
Introduction to Quantum
Theory
Electronic configuration
MINGGU
PENGAJA-
RAN
ASC 0301
TOPIK
8 Periodic Table
9 Periodicity
10
Chemical bonding
Ionic BondCovalent Bond
11Polar Bond
VSPER Theory
12 Valence Bond Theory
13Intermolecular Forces and
Solubility
14
Important Elements in Fertilizer
Important elements in Industry
(PRESENTATION)
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Lower THigher T
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Properties of Matter
Matter exhibits two types of properties :
Physical property is displayed by a sample ofmatter without undergoing any change in itscomposition
It includes mass, color, temperature, volume,density, melting point, etc.
Chemical property is displayed by a sample ofmatter as it undergoes a change in its composition.
This includes flammability, toxicity, reactivity,acidity, corrosiveness, etc.
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Matter
In a physical change, there is no change incomposition; no new substances are formed.
Examples: evaporation, melting, dissolution,crystallization
In a chemical change or chemical reaction,matterundergoes a change in composition; newsubstance are formed.
Examples: corrosion of metals, polymerization of
alkene, fermentation of food.
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Element, Substance and Compound
Substance is matter that has a definite compositionand do not vary from one sample to another.
Substances are either elements or compounds
Element is matter that cannot be broken down intosimpler substances by chemical reaction.
Compound is made up of two or more elements,chemically bonded in definite proportions and can
be broken down into simpler substances.
Terms Substance and Compound are oftenused synonymously
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Mixture
A mixture can contain two or more differentcomponents in varying proportions.
A homogeneous mixture has the samecomposition throughout a sample of matter.Components are indistinguishable. Examples: alloy,air, salt water.
A heterogeneous mixture varies in composition
from one part of the mixture to another.Components are distinguishable. Examples: Mixtureof salt and charcoal.
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Types of Matter6/4/201315
Matter (may be solid, liquid,
or gas): anything that occupiesspace and has mass
Homogeneous matter:uniform composition throughout
Heterogeneous matter:nonuniform composition
Substances: fixedcomposition; cannotbe further purified
Solutions: homogeneousmixtures; uniform composthat may vary widely
Elements: cannot be subdividedby chemical or physical changes
Compounds: elementsunited in fixed ratios
Physically
separable into
Physically
separable into
Chemically
separable into
Combine chemically
to form
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Atoms
The building blocks of matter; the smallest unit ofmatter that participates in a chemical reaction.
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Molecules
A molecule is the smallest particle of an element
that can have a stable independent existence.Usually have two or more atoms bonded together
Examples of molecules:
H2 O2 S8 NaCl H2O CH4 C2H5OH
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Chemical Formulas
Chemical formula shows the chemical compositionof the substance. Ratio of the elements present inthe molecule or compound.
Monatomic elements: He, Au, NaDiatomic elements: O2, H2, Cl2
More complex elements: O3, S4, P8
Compounds: H2O, NaCl, C12H22O11
Substance consists of two or more elements
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Ions
Cations consist of one atom
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.
Group 1 Group 2 Group 3
Li+ , lithium ion Be2+ , beryllium ion Al3+ , aluminium ion
Na+ , sodium ion Mg2+ , magnesium
ionK+ , potassium
ion
Ca2+ , calcium ion
Rb+ , rubidium
ion
Sr2+ , strontium ion
Cs+ , cesium ion Ba2+ , barium ion
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Anions consist of one atom
H-, hydride N3-, nitride O2-, oxide F-, fluoride
C-, carbide P3-, phosphide S2-, sulfide Cl-, chloride
Si4-, silicide As3-, arsenide Se2-, selenide Br-, bromide
Transition Metals and Post-Transition metals
Cr2+, chromium(II) ion
Cr3+
, chromium(III) ion
Sn2+, tin(II) ion
Sn4+
, tin(IV) ion
Mn2+, manganese (II) ion
Mn3+ , manganese (III) ion
Pb2+, lead(II) ion
Pb4+ , lead(IV) ion
Fe2+, iron(II) ion
Fe3+,iron(III) ion
Cu+, copper(I) ion
Cu2+ , copper(II) ion
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Polyatomic ions contain more than one
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Polyatomic ions contain more than one
atom.6/4/201322
NH4+, ammonium CO3
2-, carbonate
H3O+
, hydronium HCO32-
, hydrogen carbonateOH-, hydroxide SO3
2-, sulfite
CN-, cyanide HSO32-, hydrogen sulfite
NO2-, nitrite SO4
2-, sulfate
NO3-, nitrate CrO4
2-, chromate
ClO-, hypochlorite Cr2 O72-, dichromate
ClO2-, chlorite PO4
3-, phosphate
ClO3-
, chlorate HPO42-
, mono hydrogen phosphateClO4
-, perchlorate H2PO42-, dihydrogen phosphate
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Ionic Compounds
Potassium chloride: KCl = K+
+ Cl-
Calcium sulphate: CaSO4= Ca2++ SO4
2-Sodium carbonate: Na2CO3 = 2Na
+ + CO32-
Barium nitrate: Ba(NO3)2 = Ba2+ + 2NO3
-
Ammonium phosphate: (NH4)3PO4 = 3NH4+ +
PO43-
Chromium(III) chloride: Cr(Cl)3 = Cr3+ + 3Cl-
Iron(II) sulphite: FeSO3= Fe2+ + SO3
2-
an ionic compound is a chemical compound inwhich ions are held together in a lattice structure by ionic
bonds. Usually, the positively charged portion consists of
metal cations and the negatively charged portion is
an anion or polyatomic ion.
http://en.wikipedia.org/wiki/Chemical_compoundhttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Ionic_bondhttp://en.wikipedia.org/wiki/Ionic_bondhttp://en.wikipedia.org/wiki/Cationhttp://en.wikipedia.org/wiki/Anionhttp://en.wikipedia.org/wiki/Anionhttp://en.wikipedia.org/wiki/Cationhttp://en.wikipedia.org/wiki/Ionic_bondhttp://en.wikipedia.org/wiki/Ionic_bondhttp://en.wikipedia.org/wiki/Ionhttp://en.wikipedia.org/wiki/Chemical_compound7/28/2019 ASC 0301z - 01- Chemistry, Matter, and Measurement - 54 slides.ppt
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ASC 0301
Imperial System
Metric System
System International (SI)Accuracy and Precision
Significant Figures
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Learning Outcomes
Apply appropriate units to describe the result of
measurement. Explain the difference between precision and
accuracy.
Apply the concept of significant figures.
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Modern Chemistry
As of 1850s onwards, chemists used weighing
balance more systematically to measure mass (aquantity of matter) in their research
Since then, better equipments and devices were
progressively invented and used; then chemistryinvolves doing all sorts of measurements (simpleand complex; visual and aided)
So, what is it that chemists measure?All sort of properties of matter - distance, vol., temp.,time, energy, area, density, velocity, frequency,luminescence, light absorbance ... etc
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Scientific measurement and unit6/4/201328
All measurements contains 2 essential pieces ofinformation:
(i) a number (the quantitative piece)
(ii) a unit (the qualitative piece)
Example:
The number 50 is somewhat meaningless without
Units.Consider this:
Daily wage = RM50/day
wt of an egg = 50g/egg
size of a square paper = 50cm x 50 cm
S l U it d St d d
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Scale, Unit and Standard
Results of a measurement are always expressed in some kindof ascale that is defined in terms of a particular kind of unit
Example : Scale of lengthBritish Imperial system French Colonial system
Inch = base unit Millimetre = base unit12 inch = 1 foot*** 10 mm = 1 cm
3 feet = 1 yard 100 cm = 1 metre***
1760 yards = 1 mile 1000 m = 1 km
For comparison and communication purposes, the scale mustbe defined by astandard ( a reference value forcomparison)
The scales of length are related & interconvertible by aconversion factor
2.54 cm = 1 inch1 cm = 0.3937 inch
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Imperial System of Unit
Still being used in Britain and USA
Weightounce, pound, ton
16 oz = 1 lb; 14 lb = 1 stone; 2240 lb = 1 ton
Lengthinch, foot, yard, mile12 inches = 1 foot; 3 feet = 1 yd; 5280 feet = 1760 yds = 1 mile
Volumecup, pint, quart, gallon
2 cups = 1 pint; 2 pints = 1 quart; 4 quart = 1 gal
Not employed in scientific work since 1960s
Confusing and have to memorize many conversion tables
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M t i S t f M t
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Metric System of Measurement
Basic/fundamental units/types of measurements are :
Type Name SymbolMass gram gLength metre mVolume litre L
Time second sEnergy joule J
Simple and easy system of measurement
Units of measurement can be multiplied or dividedby
a factor 10
Can use prefixes to change size of unit
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Metric System Prefixes
Base units in the Metric System can be convertedinto units that are more appropriate for the quantitybeing measured by adding a prefix to the name ofthe base unit. Common metric prefixes are:
Prefix Symbol Meaningfemto- f x 1/1,000,000,000,000,000 (10-15)
pico- p x 1/1,000,000,000,000 (10-12)nano- n x 1/1,000,000,000 (10-9)micro- x 1/1,000,000 (10-6)milli- m x 1/1,000 (10-3)centi- c x 1/100 (10-2)
deci- d x l/10 (10-1
)kilo- k x 1,000 (103)mega- M x 1,000,000 (106)giga- G x 1,000,000,000 (109)tera- T x 1,000,000,000,000 (1012)
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Systeme Internationale(SI Units of Measure)
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Before 1960, Science uses the Metric System of UnitsAfter 1960, the International System of Units
(SI = Le Systeme Internationale) was proposed.
A modern version of the Metric System of Units.
It is used globally in science, industry and commerce
as a standard/reference measurement units.
The seven base/standard units of the SI system are:
length meter m
mass kilogram kg
time second sElectric current ampere A
Temperature kelvin K
Amount of substance mole mol
Luminous intensity candela cd
U it t id SI t
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Units outside SI systemhonorary units
SI has 7 base/fundamental units 3 more are included as honorary members
Base unit Symbol Dimension1. Litre L 1 L = 1 dm3 = 103 ml
2. Metric tonne t 1 t = 103
kg3. Unified atomicmass unit amu (u) 1 u = 1.66054 X 10-27 kg
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Derived SI units
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Derived SI units[dimension]
Other units of measurement can be derived by combining one
or more of the 10 SI base units. Some of the common non-SI orderived units used in chemistry are :
Physical Quantity Name of derived unit Symboldensity kg/m3
electric charge coulomb C (A.s)
electric potential volt V (J/C)energy joule J (kg-m2/s2)force newton N (kg-m/s2)frequency hertz Hz (s-1)pressure pascal Pa (N/m2)
velocity meters/second m/svolume cubic meter m3
** Symbol of a derived unit is termed the DIMENSION/UNIT of thephysical quantity
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Exact numbers
Exact numbers = numbers that are known/exact by
definition They are called exact values because they are
measured in complete units and are not dividedinto smaller parts.
Examples of exact values: 17 people; 28 cars
Conversion factors have an infinite (never ending)number of significant figures.
Examples:
60 seconds in one minute
1000 meters in one kilometer7 days in one week
1 inch = 25.4 mm
1 yard = 36 inches
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Measured numbers
Measured numbers= an actual estimated
reading:
(a) as shown by meters/detectors of instruments
(b) by visual account from calibrated/graduated
equipment (burette, pipette)(c) from mathematical calculations (average,
standard deviation)
Measurements by these methods have inherentuncertainty or experimental errors
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MeasurementChemistry is an experimental science; it involves
measurements of properties of matter
Measuring properties of matter involves 3 parameters:(a) magnitude/quantity(b) base unit or dimension
(c) uncertainty/error
Example: weighing a sample of salt(a) average magnitude = 5.7076(b) base unit = gram(c) uncertainty (using 4 different balances)
5.6785 g; 5.702 g; 5.65 g; 5.8 g
So, what is the true/real weight of the salt sample?
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ypes o exper men a errors
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ypes o exper men a errors(Lab no 1ASC 0301)
SystematicInstruments not calibrated properlyReagents are not correctly and properly preparedImperfections/limitations of instrument and glasswareCan be improved by proper calibration, adherenceto strict preparation procedures, use more sensitiveand reliable instruments, run control/blanks ... etc
RandomTests done at different times, different room T ... etcPersonal mistakes and carelessnessCan be improved by tight control of environmentalfactors, replication of tests, applying appropriatestatistical analyses on data obtained ...etc
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U t i t i t
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Uncertainty in measurement
Measurement of a property of matter involves 2
parameters(A) PRECISION(B) ACCURACY
(A) PRECISION = degree of reproducibility i.e.
(a) how close are the measurements to each other(b) how well they agree with each other
(B) ACCURACY = how close measurements are to thetrue/accepted value
AIM = experimental measurements must be as preciseand accurate as possible; i.e. least possible errors
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Accuracy vs Precision
Accuracy refers to the proximityof a measurement to the true(accepted) value of a quantity.
Precision refers to the proximity ofseveral measurements to eachother.
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In the real world, we never know whether themeasurement we make is accurate. Why not?
We make repeated measurements; calculate the mean,x and the standard deviation, s,
We hope (but not always correctly) that good precisionimplies good accuracy.
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Accuracy vs Precision
Uncertainty in measurements
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Uncertainty in measurements
Different measuring devices have differentuses and different degrees of accuracy.
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Uncertainty in measurements
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Uncertainty in measurements 6/4/201344The smallest division of this graduatedcylinder is 1 mL. Therefore, our reading
error will be 0.1 mL or 1/10 of the smallestdivision. An appropriate reading of thevolume is 36.5 0.1 mL. An equallyprecise value would be 36.6 mL or 36.4mL.
The smallest division in this buret is 0.1mL. Therefore, our reading error is 0.01
mL. A good volume reading is 20.380.01 mL. An equally precise answerwould be 20.39 mL or 20.37 mL.
Significant figures 6/4/201345
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Significant figures
Topics Determining the number of significant figures
Scientific notation
Addition & Substraction
Multiplication & Division
Rounding off
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Significant figures
When we measure quantities, esp. for the very first time,it is difficult to know if measurement is accurate.
To know if a measurement is accurate, you need toknow its true value. If you knew its true value, then,
you dont need to do the measurement!
But, it is easy to know if your measurements are precise.One indicator of the preciseness of a measurement is
the number of significant figures in a measurednumber.
Significant figures relate to certainty of themeasurement. As the number of significant figures
increases, the more certain is the measurement.
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Number of significant figures
Significant figures = number of digits that expressesthe result to the true measured precision
Example: Consider a number
92.154 (5 sig. Figures)
Start from the left and count the digits. There is5 significant figuresin this number
DO NOT worry about the decimal point !!
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Zeroes in significant figures
Zeroes are special digits
Sometimes they count as a sig. digit, sometimes theydont. It depends on their position.
Example: 0.092060 has 5 significant figures
First two zeroes are not significant, they are justposition holders
So, when counting significant digits, always start fromthe left and don't start counting until you meet the firstnon-zero digit. Then everything after that counts,including the zeroes !!
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6/4/201349
Rules for counting significant figures are summarizedbelow.
Leading zeros are not significant.0.421 has three significant figures.
Zeros within a number are always significant.Both 4012 and 40.05 contain four significant figures.
Trailing zeros in the whole number are not significant.Thus, 470,000 has two significant figures.
Trailing zeros that aren't needed to hold the decimalpoint are significant.For example, 114.20 has five significant figures.
Scientific notation 6/4/201350
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Scientific notation
A good way to avoid problems of significant and non-
significant zeroes is to use scientific notation
Example
920000 = 9.2 x 105 Has 2 sig. figs.
0.092067 = 9.2067 X 10-2 Has 5 sig. figs.
0.092 = 9.2 X 10-2 Has 2 sig. figs.
0.0920 = 9.20 X 10-2 Has 3 sig. figs.
When using scientific notation, all digits includingzeroes are significant
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di ff6/4/201351
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Rounding off
Chemistry is an inexact science
All physical measurements have some error
Thus, there is some inexactness in the last digit of anynumber
Use what ever round-off procedures you so choose
Reasonably close answers are acceptable
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Ro nding significant fig res 6/4/201352
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Rounding significant figures
A salt sample is weighed 3 times:12.4330 g 12.4334 g 12.4335 g 6 sig. figures
Calculate the average:(12.4337 + 12.4334 + 12.4335) / 3 = 12.43353333(calculator display)
Makes no sense to write down all the numbers; averagevalue cannot have sig. figures more than that of themeasurements.
Need to round off the number to the correct number ofsig. figures.
In this caseInsignificant digits 3333 are dropped2.43353333 is rounded off to 6 sig. figures; i.e.12.4335
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Rounding off numbers 6/4/201353
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Rounding off numbers
When insignificant digits are dropped from anumber, the last digit should be rounded for bestaccuracy
Example :
To determine how the last digit should be rounded,
convert the digits to be dropped to a decimal fraction( .333333); then follow the rules for rounding numbers
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Rules for rounding numbers to the 6/4/201354
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Rules for rounding numbers to thecorrect number of significant figures
1. If the decimal fraction is greater than ,
add one to the last digit retained
2. If the decimal fraction is less than ,
do not change the last retained digit
3. If the decimal fraction is exactly ,
add one to the last digit retained if it is odd
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Examples
Round off 9.473, 9.437, 9.450 & 9.750 to 2 sig. figures.
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For 9.473 the last digit retained is 4; decimal fraction is.73. So Rule #1 applies; 9.473 is rounded to 9.5
For 9.437 the last digit retained is 4; the decimalfraction is .37. So Rule #2 applies; 9.437 rounded to 9.4
For 9.450 the last digit retained is 4; the decimalfraction is .50. So Rule #3 applies; 450 is rounded
to 9.4
For 9.750 the last digit retained is 7; the decimalfraction is .50. So Rule #3 applies; 9.750 is rounded
to 9.8
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THANK YOU