2012/2013 - Section 2

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2012 / 2013 - Section 2

1b) (I) Explain how, using the results of other people, may help you decide if your investigation is reproducible

Back 1

Answer: It can help because if the results of 3 different classmates come back with results like 5 minutes, 2 minutes and 10 minutes,

you can tell that the it is not reproducible, whereas if all of them are within a close range, it is most likely reproducible.

Front 2

1b) (ii) What was the Independent Variable in the investigation you did?

- What was the range of the independent

variable?

- Explain why this was or was not a suitable range.

Back 2

(ii) The concentration of acid was the

independent variable

- The range was from 0.2 mol/dm3 to 1.0 mol/dm3

- This range was suitable because it covers a wide spectrum of acid concentrations without risking safety needlessly.

Front 3

1c) Did you get any anomalous results?

Explain your answer.

Your explanation should include examples from your results.

Back 3

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Front 4

2014 - Section 1

When you have completed your experimental work, you may be asked to compare your results with others.

Explain the advantages of comparing your results with others.

Back 4

You can identify anomalous results within your own results. If other people have used different variables (different acids), you can see what you should have done better or improved on. It also checks if your results match other people's and fit the data trends.

Front 5

5) Make sure that you hand in your Candidate Research Notes and your blank table for the

results with this paper.

You will be awarded up to two marks for your

table.

(2 marks)

Back 5

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Front 6

2015 - Section 1

1) Write down your hypothesis.

- Explanation

Back 6

Hypothesis: The higher the concentration of acid, the faster the rate of reaction

- Explanation: This is because by increasing the concentration you increase the chances of more successful particle collisions as there is more energy.

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2) Think about the research you did to find out how to test your hypothesis. Identify two sources you used for your research.

- Compare the usefulness of the two sources.

Back 7

1) CGP Revision guide

2) Textbook

I have ranked the revision guide first because it contains condensed, interesting and

simplified information that is easy to

understand. There are clear diagrams that clearly depict how to carry out an experiment similar to my own.

The textbook, on the other hand, was dull and had information that wasn't particularly

necessary. There were no diagrams and the page didn't have much colour. It wasn't useful in providing me with information about my

experiment.

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3) From the research you have done, describe in detail how you are going to do your investigation.

You should include:

- The equipment you plan to use

- How you will use the equipment

- The measurements that you are going to make

- How you will make the investigation a fair test

- A risk assessment

Back 8

Equipment:

- 30ml of Nitric Acid - concentration 0.2 - 1.0mol/dm3

- Bung

- Delivery tube

- Conical Flask

- Magnesium Ribbon x2 pieces of equal length

- Syringe

- Boss stand and clamp

- Stopwatch

Measuring: The effect of the concentration of acid on the rate of reaction

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Method:

1) Assemble the boss stand and clamp

2) Place the syringe securely in the clamp and tighten

3) Attach a delivery tube to the syringe's

nozzle. Ensure it doesn't slip off as it would let gas escape if it did.

4) Pour 30ml of Nitric acid into a conical flask.

5) Quickly put two pieces of Magnesium

ribbon (of equal length) into the acid.

6) Put a bung in the top of the conical flask to stop gases escaping.

7) Immediately start the stopwatch as soon as the Magnesium ribbon is in the acid

8) When the syringe reaches the '50ml' mark, stop the stopwatch and record the time.

Back 9

Fair test: The investigation will be made fair by only changing the concentration of acid by 0.2mol/dm3 each time. Everything else will be the the same.

Risk assessment:

- High acid concentration -

handle carefully as it will

irritate the skin/ blind you if it comes into contact with skin or eyes - Wear safety goggles as a

precaution. If it comes into contact with skin, wash area under cold water immediately.

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- Glass conical flask/ syringe - handle cautiously as broken glass is sharp and can cut - If glass smashes, clean it up with a dustpan and brush and inform the teacher of the smash.

Back 10

9) Repeat the experiment with

concentrations of acid that

increase by 0.2mol/dm3 each time.

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2015 - Section 2

1a) Do your results support the hypothesis you investigated?

You should use any pattern that you can see in your results to support your answer.

You should include examples from your

results.

Back 11

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1d) Most investigations contain errors or

uncertainties.

What do you think was the cause of the largest error in your investigation?

- What could you do to reduce the size of this error or uncertainty if you were to repeat the investigation? Explain you answer.

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Front 13

2015 - Case Study - Temperature + Rate of

Reaction

2a) Draw a sketch graph of the results in Case Study 1. The graph should show how the

temperature rise of the water varies with the mass of Calcium Oxide used.

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Front 14

2b) A food manufacturer is designing a range of food for hikers.

The manufacturer states the following

hypothesis:

"The temperature rise for any food depends on the amount of Calcium Oxide used in the heating pack"

Look at case studies 1, 2 and 3.

Explain whether or not the results in Case Study 1, 2 and 3 support this hypothesis.

To gain full marks, your explanation should include appropriate examples from the results in Case Studies 1, 2 and 3.

Back 14

No. None of them support this hypothesis

because the Case Studies don't relate in any way to food manufacturing or Calcium Oxide. Case Studies 1 and 2 are about the effect of temperature on the rate of reaction and Case Study 3 is about the effects of temperature and concentrations of acids on the rate of reaction.

Front 15

2c) Look at Case Study 4.

Use data from Case Study 4 to explain why these results do not support the manufacturer's

hypothesis.

Back 15

As before, there is no connection for either food and Calcium Oxide in this Case Study. The study is about the effects of temperature on the drying times of car paints.