Get premium membership and access questions with answers, video lessons as well as revision papers.
(i) Pour 5 cm of the acids in the table below into test-tubes. Place a piece of metal foil in
each test-tube. Note the formation of hydrogen and compare the different rates at which
the bubbles are formed.
Rate of formation of hydrogen gas - very rapid, rapid, slight, very slight, none
Metal (b) 3M hydrochloric acid (c) 3M sulphuric acid
Magnesium (b) Very rapid (c) Rapid
Aluminium (b) Slight (c) None
Zinc (b) Moderate (c) Slight
Iron (b) Very slight (c) Very slight
Tin (b) None (c) None
Lead (b) None (c) None
Copper (b) None (c) None
(ii) Recover the zinc after the reaction has ceased. Evaporate the solution to leave zinc
sulphate crystals. Dissolve the colourless zinc sulphate crystals in water and put two carbon
electrodes (central poles of dry cell batteries) in the solution. Connect the electrodes to a
6-volt or 12 volt DC supply. Zinc forms rapidly on the cathode.
sharon kalunda answered the question on April 12, 2019 at 08:36
- Describe how sodium reacts with water.(Solved)
Describe how sodium reacts with water.
Date posted: April 12, 2019. Answers (1)
- Describe an experiment to show how copper is displaced from aqueous solution of copper ions.(Solved)
Describe an experiment to show how copper is displaced from aqueous solution of copper ions.
Date posted: April 12, 2019. Answers (1)
- Describe the electrolysis of water.(Solved)
Describe the electrolysis of water.
Date posted: April 12, 2019. Answers (1)
- Describe the electrolysis of solutions of ionic salts.(Solved)
Describe the electrolysis of solutions of ionic salts.
Date posted: April 12, 2019. Answers (1)
- Describe the electrolysis of lead bromide.(Solved)
Describe the electrolysis of lead bromide.
Date posted: April 12, 2019. Answers (1)
- Describe how electrolysis is used to determine the salts which conduct electricity in solution form.(Solved)
Describe how electrolysis is used to determine the salts which conduct electricity in solution form.
Date posted: April 12, 2019. Answers (1)
- Describe an experiment to show that some liquids conducts electricity.(Solved)
Describe an experiment to show that some liquids conducts electricity.
Date posted: April 12, 2019. Answers (1)
- Explain how to identify Solids that conduct electricity in the laboratory.(Solved)
Explain how to identify Solids that conduct electricity in the laboratory.
Date posted: April 12, 2019. Answers (1)
- Describe an experiment to estimate the size of an oil molecule.(Solved)
Describe an experiment to estimate the size of an oil molecule.
Date posted: April 12, 2019. Answers (1)
- Describe an experiment to show how diffusion in liquids occurs.(Solved)
Describe an experiment to show how diffusion in liquids occurs.
Date posted: April 12, 2019. Answers (1)
- Explain how the diffusion rates of ammonia and hydrogen chloride gases can be compared.(Solved)
Explain how the diffusion rates of ammonia and hydrogen chloride gases can be compared.
Date posted: April 12, 2019. Answers (1)
- Describe an experiment to show how diffusion of a heavy carbon dioxide gas occur in an upward direction.(Solved)
Describe an experiment to show how diffusion of a heavy carbon dioxide gas occur in an upward direction.
Date posted: April 12, 2019. Answers (1)
- Describe various experiments to show how crystals grow. (Solved)
Describe various experiments to show how crystals grow.
Date posted: April 12, 2019. Answers (1)
- Explain how plant extracts can be used to indicate whether a substance is acidic or basic.(Solved)
Explain how plant extracts can be used to indicate whether a substance is acidic or basic.
Date posted: April 12, 2019. Answers (1)
- Describe how you can extract coloured substances from plants.(Solved)
Describe how you can extract coloured substances from plants.
Date posted: April 12, 2019. Answers (1)
- Give an experimental procedure to investigate what combines with iron during rusting. (Solved)
Give an experimental procedure to investigate what combines with iron during rusting.
Date posted: April 12, 2019. Answers (1)
- Describe an experiment to determine the conditions for rusting and to establish the best metal which can be used to prevent rusting among zinc, copper...(Solved)
Describe an experiment to determine the conditions for rusting and to establish the best metal which can be used to prevent rusting among zinc, copper and tin.
Date posted: April 12, 2019. Answers (1)
- Explain how carbon dioxide is used in cooking.(Solved)
Explain how carbon dioxide is used in cooking.
Date posted: April 12, 2019. Answers (1)
- Describe how Carbon dioxide is prepared,collected and tested in the laboratory.(Solved)
Describe how Carbon dioxide is prepared,collected and tested in the laboratory.
Date posted: April 12, 2019. Answers (1)
- Describe how Ammonia gas is prepared,collected and tested in the laboratory.(Solved)
Describe how Ammonia gas is prepared,collected and tested in the laboratory.
Date posted: April 12, 2019. Answers (1)