1. Find the values of a, b, c and d such that the following equation would be balanced:
aAl2S3 + bH2O → cAl(OH)3 + dH2S
2. Christian Schoenbein discovered ozone, O3, in 1839.
Ozone in air can be detected using paper strips that have been soaked in a mixture of starch and potassium iodide solution. The paper changes colour when ozone is present.
Ozone reacts with potassium iodide and water to form iodine, oxygen and potassium hydroxide.
Write the balanced chemical equation for this reaction.
3. In many bathroom cleaning products, the bleaching agent is the hypochlorite ion, ClO–(aq).
Hypochlorite bleaches can be made by reacting sodium hydroxide with chlorine. Sodium hypochlorite, sodium chloride and water are formed.
Write a balanced equation for the reaction.
4. Hydrogen has been named as a ‘fuel for the future’. In a recent article researchers reported success in making hydrogen from glycerol:
C3H8O3(l) → CO2(g) + CH4(g) + H2(g)
Balance this equation.
5. Methane is produced in the reaction of aluminium carbide with water.
Al4C3 + H2O → Al(OH)3 + CH4
Balance the above equation.
6. Carbon monoxide can be produced in many ways.
One method involves the reaction of carbon with an oxide of boron.
B2O3 + C → B4C + CO
Balance this equation.
7. Nitrogen dioxide gas can be prepared in different ways.
It is manufactured industrially as part of the Ostwald process. In the first stage of the process, nitrogen monoxide is produced by passing ammonia and oxygen over a platinum catalyst.
NH3(g) + O2(g) → NO(g) + H2O(g)
Balance the above equation.
8. When exploded, glycerol trinitrate decomposes to give nitrogen, water, carbon dioxide and oxygen.
Balance the equation for this reaction.
C3H5N3O9(l) → N2(g) + H2O(g) + CO2(g) + O2(g)
9. Acid-base reactions are common in chemistry.
Write the balanced equation for the reaction between copper(I1) oxide and nitric acid.
