wlwlAspley State High School

Science Department

Subject: Chemistry

ASSESSMENT TASK 4 Identification: EEI

Extended Experimental Investigation

Term 4, Semester 2, 2013Draft Date: / 10 / 2013Due Date: / 11 / 2013Time: 6 weeks

Name:________________________ Class: ________

Teacher: ______________

Assessment Criteria

(details attached)

This Extended Experimental Investigation (EEI) provides the student with an opportunity to:

1. design an investigation (using experiments),

2. locate and collect data,

3. process the data and

4. present the data in an assignment form.

A+AA-B+BB-C+CC-D+DD-E+EE-

KCU

IP

E & C

Metals for camping

Schools out! You are going on a camping trip to the beach for the summer break. New tent pegs are needed for the trip and they are available in four different types of metal:-

Aluminium

Copper

Zinc

Iron

In order to make an appropriate choice for the conditions the chemical and physical properties of the metals must be examined. Through research two metals will be eliminated based on properties that will make them less suitable for the purpose.

To discriminate between the final two metals a series of experiments must be performed and the results used to justify the final selection. The experiments may involve investigating factors that affect corrosion and procedures/treatments/solutions which avoid/reduce corrosion.

Recommendations may also be made to improve the durability/ longevity of the tent peg chosen.

NOTE: You may work individually, with a partner or in a group of 3 to perform the experiments, however each person is responsible for their own individual assignment presentation.

Notes for Assignment Presentation

Ownership of Work

It is the responsibility of every student to ensure the work is your own work. In chemistry you will often be doing experiments in groups and sharing results however the analysis must be completely your own. You must not copy another students work and submit this as your own.

Plagiarism

Plagiarism is copying directly (word for word) from a reference source like a textbook, encyclopaedia or from a website. Plagiarism is not permitted. Instead you are asked to re-arrange the information and put it into your own words. You must still acknowledge the source

BookBrown, J (1999) Science and Society, Sydney: McGraw- Hill

Journal ArticleSparks, M (2001) Science Pracs QST, University of Queensland Press

EncyclopaediaArcheology (1998) The World Book Encyclopaedia pp556-557.

CD RomInsects (cd rom) (1997) Canberra: CSIRO

InternetTools of Exploration [On-line] http://www.nasa.edu/ceps/ (1998)

Any resource listed in the bibliography should be cross-referenced by footnoting.

Please use following footnoting method for referencing. Use quotation marks for direct quotes.

Metal corrosion reactions are all oxidation-reduction reactions.1

(And at the bottom of the page:)

__________________________________________________________________________

1 Farrelly, R., Garnett, P., Irwin, D. and Vitlin, D (2002) Chemistry Contexts 2, Melbourne: Pearson Education Australia Pty. Ltd.

Assignment Format

The assignment should be formatted in the following manner

1. Title page

2. Table of contents

3. Abstract this is a precise summary of the Experimental Report and thus it should be written at the end of the investigation. It should contain details of the metals investigated, the experiments conducted and justification of the metal selected. The abstract is written in past tense and in the third person i.e. do not use I, We etc.

4. Introduction this section outlines the chemistry behind the investigation and contains relevant general information concerning corrosion and the properties of metals.

5. Main Body the main body could be separated into two sub sections. The first may contain specific research information on corrosion and the physical and chemical properties of the metals, and the second the experimental reports.

Experiment Presentation

Each experiment should be written in the appropriate format: Background, Aim, Apparatus, Method, Results, Discussion, Conclusion.

The Background should reveal some theoretical background and describe why the experiment is being conducted. (What is the relationship between ?)

The Aim should be clearly stated Examples: To investigate the relationship between x and y or to investigate the effect of a on b. (Remember you must revisit the aim when considering your results, discussion and conclusion)

The Apparatus must include a complete list of all equipment and chemicals. Remember if using an acid the chemical concentration should be given.

The Method describes all the steps in a logical and descriptive sequence. (Another person should be able to perform the experiment by following the method.)

The Results include the raw data, (eg measurements directly from the experiment), manipulation of this data (eg graphing the raw data) and a written description of the results. The results must be effectively presented, accurate and show appropriate units.

The Discussion should (1) restate the results which (2) then lead to and identify a trend or pattern (3) the pattern or trend will then be compared to the aim and (4) lead towards a conclusion. The discussion should also identify sources of error and areas of weakness which then lead to suggestions for improvement and further experiments. The discussion reveals the authors thought process and problem solving abilities.

The Conclusion sums up the findings. No new information should be introduced at this point. It is a vital component which completes the experiment.

6. Discussion an overall discussion should be written for the Investigation. It should contain details as to the reasons the final metal was selected, (based on experimental findings and research), and may include suggestions as to methods of increasing the longevity of the tent peg. The discussion/recommendations and conclusion should be between 1500-2000 words7. Conclusion This should be succinct and provide details as to the properties that make the selected metal preferable.

8. Reference list a complete list of references used (these must be cited in the text)9. Appendices information used in the appendices must be referred to in the textName: _____________________

Draft CopyExtended Experimental Investigation (EEI)

Metals for Camping

Task: Research and perform experiments to investigate corrosion and properties of metals.

Designing the Extended Experimental Investigation Draft

1.Identify the questions/problems that need to be answered Reword the task in your own words (Hint you may need to clarify and give examples of terms like corrosion and research the relevant properties of metals)

2. Identify sources for secondary data collection

3. Identify experimental ideas

Brief description (include variables to be manipulated)Result collection identify qualitative and quantitative results. Time estimate

Preliminary Experiment/s

Investigate corrosion/properties of metals

Further Experimentation

Design and perform experiment/s based on the results of preliminary investigations.

The results should show differences between the two metals chosen.

Final Experimentation

Design and perform experiment/s that will further discriminate between the two metals.

Procedures and treatments to avoid/reduce corrosion may also be investigated

4. Complete the table below to propose your time management and action plan.

Stage of InvestigationWhat has to be doneWhen and how long this will take

Locating and collecting secondary data

Collecting primary data

(experiments)

NB Exp requests require 24 hours)

Processing Data

Communicating Information

Other relevant information (this may include ideas on problems which may be encountered and how these may be resolved.

Year 11 Chemistry

Experiment Request (48 hours prior to experiment)

Name/s:

Request for:

Day: Date:

Brief description of the experiment:

Chemicals requiredQuantityTick to indicate you have checked the MSDS information are there special instructions for use or disposal?

Equipment:QuantityEquipment:Quantity

Risk Assessment. (self assessment to perform your experiment safely) (tick the box to agree)

I/We have read and understood the procedures for the experiment.

I/We have checked the MSDS information on all the chemicals involved in the experiment.

I/We will wear appropriate protective clothing (lab coats and glasses).

I/We will ensure that potential hazards including spillage, inhalation, absorption, ingestion, sharp objects and combustion ) are identified and will follow the safety procedures to avoid injuries.

I/We will dispose of chemicals appropriately.

Student Ownership Statement.

I declare that:

This assignment is my own work and I have not copied other students work or directly from textbooks or other sources. I have not gained unfair assistance from other students, parents or guardians.

STUDENT SIGNATURE ______________________DATE SUBMITTED: _________________

Carefully cut along the dotted line when you are ready to hand in your assignment.

-----------------------------------------------------------------------------------------------------------

Assignment Receipt

Year 11 Extended Experimental Investigation (EEI)

Metals for Camping

Name: _______________________________

Date: __________________

Received: ________________________________

(Teacher)

MINIMUN STANDARD:THE STUDENT HAS COMPLETED THE FOLLOWING:

Completed practical aspect to demonstrate an understanding of corrosion.

Has written an introduction, materials and method, results and discussion.

Has handed in a scientific journal. COncl

Extended Experimental Investigation (EEI) Corrosion Assessment Criteria

CriteriaGeneral objectivesABCDE

KCURecall & interpret concepts, theories & principles( Abstract

( Overall Introduction

(Experimental introduction Reproduces and interprets complex and challenging concepts, theories and principals about the chemistry behind corrosion, how it occurs, why and ways that are used to prevent it.

References are cited accurately. Reproduces and interprets complex or challenging concepts, theories and principals about the chemistry behind corrosion, how it occurs, why and ways that are used to prevent it.

References are cited accurately. Reproduces concepts, theories and principals about the chemistry behind corrosion, how it occurs, why and ways that are used to prevent it.

Reproduces simple ideas about corrosion, how it occurs, why and ways that are used to prevent it.

Reproduces isolated facts about the chemistry of corrosion.

Describe and explain processes and phenomena of chemistry (Experimental discussions (Experimental conclusionsCompares and explains the complex concepts, processes and phenomena of the experimental investigation in the discussion.

Conclusion is concise and accurate.Compares or explains the complex concepts, processes and phenomena of the experimental investigation in the discussion.

Conclusion is concise and accurate.Explains the simple processes and phenomena of the experimental investigation in the discussion.

Conclusion is concise. Description of simple processes and phenomena of the experimental investigation in the discussion.

Conclusion is statedRecognition of isolated simple phenomena of the experimental investigation in the discussion.

Conclusion is stated.

Link and apply algorithms, concepts, theories and schema of chemistry. (Overall Discussion

(ConclusionLinking and application of algorithms, concepts, principals, theories and schema about corrosion to find solutions to the investigation in a complex and challenging situation, to write the discussion and conclusion.Linking and application of algorithms, concepts, principals, theories and schema about corrosion to find solutions to the investigation in a complex or challenging situation, to write the discussion and conclusion.Application of algorithms, concepts, principals, theories and schema about corrosion to find solutions to the investigation in a simple situation, to write the discussion and conclusion.Application of algorithms, concepts, principals, theories and schema about corrosion to write the discussion and conclusion. Application of simple given algorithm to write the discussion and conclusion.

Investigative Processes Conduct and appraise chemical research Task ( Hypothesis

( Materials & method

(EEI Design

(Evaluation of Methods Formulation of justified significant hypothesis which inform effective and efficient design, refinement and management of the experimental investigation.

Formulation of justified hypothesis which inform effective and efficient design, refinement and management of the experimental investigation.

Formulation of justified hypothesis to select and manage the experimental investigation. Implementation of given experimental investigation.

Guided use of experimental investigation.

Operate chemical equipment and technology safely(Risk assessment (Skills.

(Log BookAssessment of risk, safe selection and adaptation of equipment, and appropriate application of technology to gather record and process valid data. A log book has been used to keep up to date records. Assessment of risk, safe selection of equipment, and appropriate application of technology to gather record and process valid data. A log book has been used to keep up to date records. Assessment of risk, safe selection of equipment, and appropriate application of technology to gather record and data. A log book has been used to keep up to date records. Safe use of equipment and technology to gather and record data. Safe directed use of equipment to gather data.

Use primary and secondary chemical data(Results

(Data analysis in DiscussionSystematic analysis of primary and secondary data to identify relationships between the theory and the investigation. Trends, errors and anomalies are accurately identified. Analysis of primary and secondary data to identify relationships between the theory and the investigation. Trends, errors and anomalies are accurately identified.Analysis of primary and secondary data to identify obvious trends between the theory and the investigation. Obvious errors and anomalies are identified. Identification of obvious patterns and trends. Records data.

Determine analyse and evaluate the chemical interrelationships involved in chemistry(Experimental DiscussionsAnalysis and evaluation of complex scientific interrelationships between the theory of corrosion and the investigation in each of the experimental discussions.Analysis of complex scientific interrelationships between the theory of corrosion and the investigation in each of the experimental discussions.Descriptions of complex scientific interrelationships between the theory of corrosion and the investigation in each of the experimental discussions.Identification of simple interrelationships between the theory of corrosion and the investigation in each of the experimental discussions.Identification of obvious interrelationships between the theory of corrosion and the investigation.

Evaluating & concludingDetermine analyse and evaluate

chemical interrelationships involved in chemistry(Overall Discussion and conclusionAnalysis and evaluation of complex scientific interrelationships between the theory of corrosion and the investigation in the overall discussion.Analysis of complex scientific interrelationships between the theory of corrosion and the investigation in the overall discussion.Descriptions of complex scientific interrelationships between the theory of corrosion and the investigation in the overall discussion.Identification of simple interrelationships between the theory of corrosion and the investigation in the overall discussion.Identification of obvious interrelationships between the theory of corrosion and the investigation in the overall discussion.

Communicate chemical information in a variety of ways

(Overall structure and presentation(Presentation of Data(ReferencesDiscriminating selection, use and presentation of scientific data and ideas to make meaning accessible to intended audiences about corrosion and the experimental investigation that was completed.

Uses innovative range of formats to present the EEI. Selection, use and presentation of scientific data and ideas to make meaning accessible to intended audiences about corrosion and the experimental investigation that was completed.

Uses innovative range of formats to present the EEI. Selection, use and presentation of scientific data and ideas to make meaning accessible to intended audiences about corrosion and the experimental investigation that was completed.

Presentation of scientific data and ideas using a range of formats about corrosion and the experimental investigation.

Presentation of scientific data and ideas.

IntroductionDifferent types of camping pegs are available in the market. But, which is one most suitable for a hot temperatures and beach soil conditions? Four metals will be investigated on their reactivity within different environments that promote corrosion, resembling those of a beach. Various types of metals last better in different soil consistency of the beach. For this report four different metals will tested on their abilty to withstand the conditions of the beach. This report will be made possible with the simulation of three different experiments.Experiment 1: Four metals elimination

Experiment 2: Electroplating (Electrolytic Cell)

Experiment 3: WD-40Properties of metals:

All metals have different properties. The properties are dependant on the typer of metal being used. Some properties of these metals are not relevant to this investigation and may be ignored.

Physical properties of metalChemical properties of metals

Form positive ions easily; do not from covalent bonds easily with the other atomsIn chemical reactions they form cations

Atoms join to form an array of a three dimentional structure known as a lattice is surrounded by delocalized electrons.Most metals react with oxygen in the air to form oxides or layers of oxides

Very good conductivity

Most are malleable

Properties that metals possess are very vital because they determine the rate of corrosion. Some properties include when zinc aluminium react with oxygen readily, these metals have the ability to form protective layers that prevent the metal from further attack from the oxygen molecules and slows down the rate of corrosion.Activity series of metals:

Oxidation and reduction:

Types of corrosion:Corrosion:

Corrosion is a process that produces a new and less desirable substance form the original metal and can result in a loss of function of the metal or the system.

Different types of corrosion:

Galvanic corrosion: This type of corrosion occurs when two different type of metals are placed in contact to each other electrically and the one metal has a higher electronegativity then the other.

Pitting corrosion: Pitting corrosion occurs in materials that have a protective film such as a corrosion product(paint) or when the coating applied on the metal breaks down. The exposed metal gives up electrons very easily and the reaction creates tiny pits into the metal.

Concentration cell corrosion: A crevice is a narrow gap between a piece of metal and another piece of metal or tightly adhering material like plastic or a film of bacterial growth. Most metals and alloys are susceptible to crevice corrosion, For example in stainless steel, crevices are the first and most common place for corrosive attack to begin.

Factors that can speed up corrosion:

1. Presence of water

2. Presence of acid

3. The concentration of the water, acid etc

4. The presence of salt

5. Contact with other metal, or electrical contact with other metalsRedox Reactions:

Electroplating:

Electroplating is a process of coating a metal by the means of electrolysis (or electrical current) . In this process the cathode and the anode are used. A cathode is a element that the negative charge flows through, and vice versa for Anode. The Cathode and the anode are connected in a series circuit in with a battery and the electrolytic bath. When power is applied through the circuit. In this process the electrolytic bath gives up its metal content to the surface of the cathode (the electrode through which charge enter an electrical device).Physical and Chemical properties of the MetalsCorrosion,

Tests to be done to rule out the two best metals for camping pegs.

Strength of the metal

Malleablility

Malleable

Ductile

Density

thermal capacity

melting point

boiling point

thermal conductivity

MalleableDensity(gm/cm3)Specific heat capacity(J/Kg) KelvinsMelting

CelciusBoiling point

CelciusTensile strength

IronNo9.045011402870350

AluminiumNo2.709006602467300

CopperYes8.9639010842475210

ZincYes7.14380419.5910200-250

--Electroplating Experiment

Introduction: Electroplating is usually a process which is executed in order to improve the appearance or the corrosion resistance of the surface of a metal by electrodepositing a thin layer of metal on it. The metal substrate that is to be electroplated is made by the cathode in an electrolytic cell. The cell which is used in electroplating contain an electrolyte which is usually an aqueous solution containing a reasonably high concentration of an ion of the metal which is to be electroplated on the surface he cell anode is usually a piece of the metal to be plated from solution; this enables the anode reaction of metal dissolution to replace the metal ion lost from solution by the cathodic decomposition. Electroplating is a valid experiment in this scenario as, from the first experiment Four metal elimination, The best metal that resisted corrosion and lost the lease amount of mass was zinc and Aluminium. And as for tent pegs, the strength of the metal is also very crucial as it will withstand a lot of pressure, so Iron was chosen as it is the strongest metal of all four metals.Factors:

1) The current that is supplied to electrolysis bath ( increase in the amount of current supplied can affect the amount of substance deposited on the cathode)

2) Time, the Longer this procedure is left to run the more substance will be deposited on the cathode.

3) Distance between both of the electrodes, If the distance between the two electrodes is great, the more distance the zinc ions require to travel to the cathode. If the distance is small, the zinc ions from the zinc stip require less energy to flow.

4) Surface are of the electrodes: The surface area of the electrodes affected the number of the ions that can be lost or gained when the current is supplied. If the surface area of the anode is greater, There will be more zinc available that can be deposited on the cathode.

5) Concentration of the electrolyte (solution) : When the electrodes are placed in the electrolyte, if the concentration of this solution is high, there are more ions that can be discharged in the reaction.

6) Temperature: If the temperature is high, it can give the ions more energy to move. When the temperature is low the ions have less energy to move from the anode to the cathode.

Aim: To find out which metal will electro plate the best, and Not gain too much mass and lose the least amount of mass, after put into the test tube with salt water. And carefully measure the amount of mass that was lost or gained after the metals were in salt water.

Hypothesis: Aluminium can be the best metal in this case, is it has a higher conductivity.

Materials: Distilled water, 12V power pack, two conducting clips, Aluminium strip (cathode), graphite strip(anode), Electrode solution (zinc)

Procedure: 1. Mix grams of zinc salt in the distilled water, until transperant.

2. Clean the cathode, so no other material remains at the surface.

3. Connect both the cathode and the anode to the alligator clips and Connect the anode to the positive terminal and the metal to be coated to the negative terminal( cathode) .

4. Then dip the Cathode and anode in the electrolyte and keep them at a reasonable distance for best results.

5.Turn on the power pack and wait 5-10 minutes.

6. Turn off the power pack and take the Zinc and Iron coated with zinc out of the solution

7. record the mass of the copper strip and compare it to the mass of the strip before experiment was conducted.

8. Then repeat this for other metals that is necessary.

9. After the metal has been coated, with zinc. Put the metal back into salt water test tube and leave it there for another 3-6 days, then record results of mass of iron with electroplating. Also measure the mass of the anode (zinc) before and after the experiment.

10. This time Aluminium will be coated with Zinc

11. Repeat same procedure above, this time Connect Aluminium (cathode) and Zinc(Anode) to the power pack, Zinc to the Positive terminal and Aluminium to the negative terminal.

12. Fill beaker with electrolyte ( Zinc Nitrate)

13. Place both metal strips to the opposite of each other in the beaker

14. turn on the electrolytic bath

15. let this procedure continue for 5 minutes then turn it off. After this procedure put the Aluminium electroplated with zinc, in the salt water solution.

16. Record results.

Diagram Of experiment:

Results:

MetalsZinc electroplated on aluminiumZinc electroplated on ironAluminium electroplated onto Iron

Mass Before put into salt solution0.99g2.02g1.86g

Mass After put into salt solution0.97g2.011.82g

Percentage lost(%)2.02%0.5%2.15%

Discussion:

Iron Electroplated with Zinc

The iron nail, instantly turned silver, which is colour of zinc. Small bubbles were also observed which seemed to be sticking to the surface of the cathode (Iron nail), these were the ions disassociated from the zinc and started to coat the iron . After about 5 minutes, the iron nail possessed a layer of zinc of about 0.5 mm. The electroplated only lost a percentage of 0.5 % after the reaction was very successful. This also proved the hypothesis correct as zinc is a resistant metal to corrosion, and Iron on the other hand was the strongest metal and very dense that it will be able to withstand the pressure of the tent.Aluminium Electroplated with zinc

This process took longer then the process of Iron electroplate with zinc. The cathode (aluminium) started to turn black, and small bubbles were found on the surface of the cathode. The layer of zinc on aluminium, was not as thick as the zinc with iron, and if observed it would not be evident that the aluminium was electroplated. After the aluminium was electroplated with zinc, It was put into the salt solution, which has the same concentration as the four metal elimination experiment. After it had reacted with the salt solution for 2 weeks, it lost 0.02g of mass and about 2.02% of overall mass. It showed, some signs of visual corrosion.Iron electroplated with AluminiumThis was the worst scenario, as the electroplating was very thin after the 5 minutes had passed. The colour of electroplated aluminium was black. No precipitate formed at the bottom of the test tube. After the electroplated nail was removed from the test tube, no visible changes were observed but the mass difference was 2.15% which the greatest of all the other electroplated metals.The purpose of this experiment was to find the effects of electroplating on Iron and Aluminium. The metal that were chosen for these metals to be electroplated with are zinc and Aluminium. Zinc was chosen to be one of the metals that will be the anode in these experiment because it reacts with oxygen to form a overly protective layer, this layer acts as a barrier for further corrosion. The other metals approximately lost4 times the mass lost in the zinc onto iron electroplating. The electroplating layer felt stronger on the zinc onto iron electroplating, which in the end was assumed to be the difference in the electrical conductivity difference between the iron, that was higher than that of the other metal ( aluminium).Errors:

1) Need to be done on a larger scale

Conclusion: When iron was plated onto the zinc, it lost the least amount of mass, and also very least amount of corrosion was noted, as the electroplating had protected the metal. No precipitates were noted, which also suggested that no loss of mass, that was unaccounted for. It was also noted that small bubbles were observed when the metal was taken out of the test tube for weighing. This suggests that the hydrogen ions tyring to penetrate the surface. And if was left long enough would have developed crevices onto the metal. (Then tell how the other metals lost more mass, and had precipitate on bottom, and the electroplating was scattered and weak). The experiment was very successful, with the utilization of all the results and observations, the most resistant to corrosion combination of electroplating and pure metal is galvanised iron.----Four metal elimination Experiment----

Introduction: In this experiment all the four main metals will be tested against, different scenarios susceptible to rusting.

Aim: To rule out two metals have are least reactive to Air, Rain water, Distilled water, Sand +water and Tap water by measuring the mass before and after the experiment and to measure the reaction rate of corrosion, to know what affects the reaction rate of these metals the most and that solution will be used for further experimentation.

Hypothesis: The aluminium and the zinc will be least reactive and will lose the least amount of mass.

Materials: 20 test tubes, 5 test tube racks, distilled water, salt water, rain water, Tap water, sand, Measuring scales, Metal clipper, ruler and all the four metals : Zinc, Aluminium, copper, Iron

Variables:

1) Air:

2) Distilled:

3) Saltwater solution:

4) Rain Water:

5) Tap Water:

6) Salt and Sand:

Procedure: 1) Measure out all the quantities for the liquid and the metals

AluminiumZincIronCopperSand WaterSalt

0.08g2.00g1.84g0.15g10g15ml7g/200ml

2) Place all the test tube in the racks and label each rack with the name of the metal, one metal = one rack

3) There are five test tubes in each rack, so place 5 pieces of each metal into each test tube.

4) For Aluminium, one test tube containing just the aluminium. The next containing the Aluminium and the Distilled water. The next one nncontaining the Alumnium and the salt water, the next containing the Rain water and the next containing the aluminium and the Tap water.

5) For zinc, one test tube containing just the zinc as this the Air test tube. The next containing the Zinc and the Distilled water. The next one containing the Zinc and the salt water, the next containing the Rain water and the next containing the zinc and the Tap water.

6) after about 1 week, take the metals out of the test tubes and measure the mass accurately and note in the table of results, then scrape the residue left on the metal and measure the mass again.

Results: Observed changes in the experiment (precipitate)

Test tube 1Test tube 2Test tube 3Test tube 4Test tube 5Test tube6

Rack 1(cu)No precipitateNo precipitateSmall amount of precipitateNo precipitateSmall amount of precipitateVery small amount of precipitate (most amount of precipitate)

Rack 2 (fe)No preceipitateSmall sign of precipitateSmall sign of precipitateSmall amount of precipitate Small amount of precipitateBig amount of precipitate around the iron nail(most amount of precipitate)

Rack 3 (zn)No signs of precipitateSmall sign of precipitateVery small amount of white precipitateVery small amount of white precipitateVery small amount of precipitate(most amount of precipitate)Small sign of precipitate

Rack 4 (Al) No observed signs of precipitateNo precipitateNo precipitateNo precipitateSmall amount of precipitateMost amount of precipitate

Oxidization (observations)

Test tube 1Test tube 2Test tube 3Test tube 4Test tube 5Test Tube 6

Rack 1(Cu)No oxidizationNo oxidizationMetal has faded, some amount of oxidization ( most amount of oxidization)Small amount of oxidization and faded colour of metalSmall amount of oxidzationSmall amount of oxidization

Rack 2 (Fe)No oxidizationSmall amount of oxidization, Fading of clour and cloudy waterSmall amount of oxidizationSmall amount of rust, fading of colourSmall MOUNT of oxidization Most amount of rust and fade of colour

Rack 3 (Zn)No physical change in the appearance of metalSmall amount of oxidizationSmall amount of oxidizationVery less amount of oxidizationVery less signs of oxidizationMost amout of oxidization, color has faded

Rack 4 (Al)No physical change in the appearance of the metalNo oxidizationMetal shows small signs of corrosion No OxidationSmall amount of oxidizationMost amount of oxidation

Aluminium

DistilledSalt WaterRain WaterTap waterSand +SaltWater +OilAir

Before reaction0.080.080.080.080.080.080.08

After reaction0.110.140.070.050.10.100.08

After Sanding0.070.050.060.050.060.070.08

Mass Lost0.010.030.0100.020.010

Percentage lost(mass lost/initialmass x 100)12.537.512.502512.50

On average lost 14%

Iron

DistilledSalt WaterRain WaterTap waterSand +SaltWater +OilAir

Before reaction1.341.921.921.921.921.841.84

After reaction1.321.881.851.821.901.861.84

After Sanding1.251.831.801.821.811.8041.84

Mass lost0.090.090.120.100.110.0380

Percentage lost6.7%5%6%5.3%6%2%0%

Average amount lost4.42%

Copper

DistilledSalt WaterRain WaterTap waterSand +SaltWater +OilAir

Before reaction0.300.300.300.300.300.300.30

After reaction0.270.250.250.270.260.260.30

After Sanding0.250.210.230.220.240.270.30

Mass lost0.050.090.070.080.060.030

Percentage lost1630232620100

17.85

Zinc

DistilledSalt WaterRain WaterTap waterSand +SaltWater +OilAir

Before reaction1.302.2022222

After reaction1.332.22.242.151.961.92

After Sanding1.272.161.902.141.901.82

Mass lost0.030.040.100.010.100.20

Percentage lost2.32%5%0.55%10%0

Average percent lost3.45%

Average mass lost in Percentage in each matal . pie graph

Figure 1This pie graph illustrates that copper was the most reactive material and lost the most amount of mass.Visible Corrosion (Average):

Day 2Day4Day6Day8Day10Day 12 Day14

Aluminium(overall)Small AmountNo change

Iron(overall)Visible signs of rust already observedCrevices noted on the surface of the metal, brown precipitate starting to form

Copper(overall)No amount of rust noticed

Zinc(overall)No rust noticed

According to the law of conservation of mass, the increased mass of nail and rust is the amount of oxygen.

Corrsion rates = [the increased amount of product] / [time]

= [the consumed mass of oygen] / [time]

= [Metals's Change in mass] / [time in the unit of days]

Discussion: The two metals which was most resistant to corrosion, in their natural form were found using the preliminary testing.(GRAPHS OF VISIBLE CORROSION, REACTION RATE and AVERAGE MASS LOST ALSO THE INITIAL AND MASS AFTER SANDING COPARISON GRAPH)

Conclusion: Reffering to background knowledge, Iron showed to have the maximum amount of tensile strength, which is vital for a tent peg, considering it did not corrode as much as it was expected to at an average. Aluminium also has the second most amount of tensile strength and is suitable for a tent peg, and is very resistant to corrosion. The hypothesis were proved to be correct and the experiment has proved very useful, in order to accumulate the best metals that resist corrosion. On the other hand aluminium also, submitted evidence of very low corrosion, very los amount of precipitate distribution. Aluminium also seemed to lose a lot of colour, and also possesses very good tensile strength. So in this case, Iron and aluminium seem to be the most suitable for the manufacturing of a tentpeg, to be used in hot and cold conditions. Iron and aluminium, will move forward for further experimentation.------Experiment three WD-40-----Theory: The oil in formula(WD-40) displaces water. The surface tension of the water is broken by the oil, and the water cannot stick to the surface that WD-40. As water is polar and the oil in WD-40 is non-polar, the water also has no attraction to the oil. It also creates a protective layer which protects the metal from reacting with the oxygen.

Aim: To see which metal of the two remaining ( Iron and Aluminium) are least resistant to corrosion, with Water displacement 40th attempt applied to them

Material: Strips of same size as Experiment 1 and the same mass, Iron and Aluminium, WD-40, Two testubes with salt water

Procedure:

1) Cut both metals exactly of that of experiment 1 and weigh them. (Aluminium and Iron)

2) Cut all the surface of both metal of both metals and coat with WD-40

3) Weigh the metal strips after WD-40 is applied

4) Carefully drop both metals into the test tube

5) After about 6 days, remove metals from the test tubes and weigh them. And compare the mass before and after the experiment.

Results:

MetalsIron WDZinc

WD

Mass before ( sanding)1.21grams1.75grams

Mass (after sanding)1.20grams1.74grams

Percentage lost(%)0.8% lost0.5% lost

Analysis:

Reaction Rate: According to the law of conservation of mass, the increased mass of nail and rust is the amount of oxygen.

Corrosion rates = [the increased amount of product] / [time]

= [the consumed mass of oygen] / [time]

= [Metals's Change in mass] / [time in the unit of days]

= Metals change in mass = 0.01

Time =7 days

Corrosion Rate: 0.01/7= 0.00142gm/day

Both metals were rusting at the same amount.

As the other experiment were conducted over the period of 14 days, but because of the lack of the time, this was only done for 7 days. But the using the reaction rate a rough estimate, of the mass lost over the 14 days can be made.

Mass lost over 14 days = 0.0014214

= 0.02g

0.02 g would have been lost if the metals were left in the salt solution over 14 days.

Discussion: A very small amount of metal was corroded, at an average of 0.01 grams. But it was suspected that as time went by the coating will wear off week by week and it will not be affective any more., as it wont be coating the Iron and Aluminium strip. The Iron showed less evidence of WD-40 Wearing of and lost only lost 0.01 gm to corrosion. After the reaction time had passed, the Metals strips had a bubbles formed around the metals, it was also observed that the WD-40 oil was distributed on the bottom, and slowly the WD-40 was wearing off the metals. It was also assumed, that the corrosion rate was the same rate for both metals, so the type of metal does not effect corrosion after WD-40 is applied.

Conclusion:WD-40 seems to be effective solution to resist corrosion on all metals, but coatings must be checked and reapplied week to week as, redox reactions will keep happening, and will damage the coating. But this not very practical and innovative, as the metals will be buried into the ground and the WD-40 coating will not last very long, as most of it will be lost when installing the tent peg into the ground.Errors:

1) Since WD-40 was applied with a spray bottle, this way some areas on the metals could have been left exposed when the metal was put into the solution, this could have made small differences on the final mass of the metal.2) Some areas could have been heavily coated, and the excess Wd-40 oil may have not been properly removed." Your discussion is your CONCLUSION. It is the most important part of the lab. In your discussion, you want to prove that you learned a lot from doing the experiment. Even if you didn't find out what you planned or your experiment went horribly wrong, you still learned something. If you don't write about how hard you worked and how very much you've learned your favorite science teacher won't give you the great grade you deserve. Write a lot! Read it again and write some more!" You should write about the following: > Answer the question you started with (your purpose). Use the #s/pictures/information you collected to prove what you say. > Explain your data. Were there any patterns in the data? Summarize all the data you collected. > Was your hypothesis correct? Explain why or why not. Use your data to prove what you say! > Where might there have been errors in your experiment? Do you trust your Data? How might your errors change your data? > Where did you have the most problems? What was the most difficult part to do? > What could you change to make this experiment better next time? # HOW COULD YOU USE WHAT YOU LEARNED IN THIS EXPERIMENT TO DEVELOPE A NEW, DIFFERENT EXPERIMENT?