Use of Techniques, Apparatus and Materials

You are not expected to do any experimental work for this question

Barium carbonate decomposes when heated. The word equation for the reaction is shown.

$$\text{barium carbonate} \rightarrow \text{barium oxide} + \text{carbon dioxide}$$

Plan an experiment to determine the percentage loss in mass when barium carbonate is heated.

Your plan must include the use of common laboratory apparatus and a sample of barium carbonate. No other chemicals should be used.

Your plan must include:

• the apparatus needed
• the method to use and the measurements to take
• procedures to ensure that the percentage determined is as accurate as possible
• how the measurements are used to determine the percentage loss in mass.

You may draw a diagram to help answer the question.

You are not expected to do any experimental work for this question.

Copper(II) carbonate reacts with dilute sulfuric acid at room temperature.

The word equation for the reaction is shown.

$$\text{copper(II) carbonate} + \text{sulfuric acid} \rightarrow \text{copper(II) sulfate} + \text{carbon dioxide} + \text{water}$$

Plan an experiment to determine the volume of carbon dioxide formed when a known mass of copper(II) carbonate completely reacts with dilute sulfuric acid.

Your plan must include the use of common laboratory apparatus, dilute sulfuric acid and copper(II) carbonate. No other chemicals should be used.

Your plan must include:

• the apparatus needed
• the method to use and the measurements to take
• procedures to ensure that the volume measured is as accurate as possible.

You may draw a diagram to help answer the question.

You are not expected to do any practical work for this question.

Muntz metal is an alloy that contains zinc and copper.

Zinc reacts with dilute sulfuric acid. Copper does not react with dilute sulfuric acid.

Plan an investigation to find the percentage by mass of zinc in a powdered sample of Muntz metal which contains only zinc and copper.

Your plan must include the use of common laboratory apparatus, Muntz metal and sulfuric acid. No other chemicals should be used.

Your plan must include:

• the apparatus needed
• the method to use and the measurements to take
• procedures to ensure that the percentage determined is as accurate as possible
• how the measurements are used to determine the percentage by mass of zinc in the sample of Muntz metal.

You may draw a diagram to help answer the question.

You are not expected to do any experimental work for this question.

Baking powder is used to make cakes rise. When water is added to baking powder, carbon dioxide gas is released.

The longer the baking powder is stored, the less carbon dioxide it releases when water is added.

Plan an investigation to show which of two different samples of baking powder has been stored for longer.

Your plan should include the use of common laboratory apparatus, the two samples of baking powder and water. No other chemicals should be used.

Your plan should include:

• the apparatus needed
• the method to use
• the measurements to take
• the variables to control
• how to use the results to determine which sample has been stored for longer.

You may draw a diagram to help you answer the question.

You are not expected to do any experimental work for this question.

Copper(II) sulfate is a salt used to kill pests on plant leaves.

Copper(II) sulfate is prepared by neutralising dilute sulfuric acid with solid copper(II) oxide.

Plan an experiment to prepare pure dry crystals of copper(II) sulfate.

Your plan should include the use of:

• common laboratory apparatus
• dilute sulfuric acid
• solid copper(II) oxide.

No other chemicals should be used.

Your plan should include:

• the apparatus needed
• the method to use.

You may draw a diagram to help answer the question.

Put $\mathbf{Q}$ into the burette.

Pipette a 25.0 $\text{cm}^3$ (or 20.0 $\text{cm}^3$) portion of $\mathbf{P}$ into a flask.

Add $\mathbf{Q}$ from the burette until the red-brown colour fades to pale yellow, then add a few drops of the starch indicator. This will give a dark blue solution. Continue adding $\mathbf{Q}$ slowly from the burette until one drop of $\mathbf{Q}$ causes the blue colour to disappear, leaving a colourless solution.

Record your results in the table, repeating the titration as many times as you consider necessary to achieve consistent results.

Results

Burette readings

Summary

Tick (✓) the best titration results.

Using these results, the average volume of $\mathbf{Q}$ required was ______ $\text{cm}^3$.

Volume of solution $\mathbf{P}$ used was ______ $\text{cm}^3$.

Put $\mathbf{Q}$ into the burette.

Pipette a $25.0\text{ cm}^3$ (or $20.0\text{ cm}^3$) portion of $\mathbf{P}$ into a flask.

Add $\mathbf{Q}$ from the burette until the red-brown colour fades to pale yellow, then add a few drops of the starch indicator. This will give a dark blue solution. Continue adding $\mathbf{Q}$ slowly from the burette until one drop of $\mathbf{Q}$ causes the blue colour to disappear, leaving a colourless solution.

Record your results in the table, repeating the titration as many times as you consider necessary to achieve consistent results.

Results

Burette readings

Summary

Tick (✓) the best titration results.

Using these results, the average volume of $\mathbf{Q}$ required was ______ $\text{cm}^3$.

Volume of solution $\mathbf{P}$ used was ______ $\text{cm}^3$.

Put P into the burette.

Pipette a $25.0\text{ cm}^3$ (or $20.0\text{ cm}^3$) portion of Q into a flask and titrate with P, using the indicator provided.

Record your results in the table, repeating the titration as many times as you consider necessary to achieve consistent results.

Results

Burette readings

Summary

Tick (✓) the best titration results.

Using these results, the average volume of P required was ______ $\text{cm}^3$.

Volume of Q used was ______ $\text{cm}^3$.

Put $\mathbf{P}$ into the burette.

Pipette a $25.0\text{ cm}^3$ (or $20.0\text{ cm}^3$) portion of $\mathbf{Q}$ into a flask and titrate with $\mathbf{P}$, using the indicator provided.

Record your results in the table, repeating the titration as many times as you consider necessary to achieve consistent results.

Results

Burette readings

Summary

Tick (✓) the best titration results.

Using the best titration results, the average volume of $\mathbf{P}$ required was ______ $\text{cm}^3$.

Volume of $\mathbf{Q}$ used was ______ $\text{cm}^3$.

Put $\mathbf{Q}$ into the burette.

Pipette a $25.0\text{ cm}^3$ (or $20.0\text{ cm}^3$) portion of $\mathbf{P}$ into a flask.

Add $\mathbf{Q}$ from the burette until the red-brown colour fades to pale yellow, then add a few drops of the starch indicator. This will give a dark blue solution. Continue adding $\mathbf{Q}$ slowly from the burette until one drop of $\mathbf{Q}$ causes the blue colour to disappear, leaving a colourless solution.

Record your results in the table, repeating the titration as many times as you consider necessary to achieve consistent results.

Results

Burette readings

Summary

Tick (✓) the best titration results.

Using these results, the average volume of $\mathbf{Q}$ required was ______ $\text{cm}^3$.

Volume of $\mathbf{P}$ used was ______ $\text{cm}^3$.