Question 1 Report
(a)(i) List two elements which react with steam at red heat to produce hydrogen.
(ii) Explain why an aqueous solution of potassium bromide turned reddish brown on bubbling chlorine through it.
(iii) Write an equation for the reaction in (a)(ii).
(b)(i) Name two types of chemical industry that use limestone as raw material.
(ii) Give one example of hygroscopic substances.
(iii) Copy and complete the table below.
| Salt to be prepared |
Starting material | Method of preparation |
| PbSO\(4\) | Pb(NO\(_3)_{2(ag)}\) | - |
| KNO\(_3\) | KOH | Neutralization |
| CaCl\(_2\) | CaCO\(_3\) | - |
| FeCl\(_3\) | Fe\(_(s)}\) | - |
| CuSO\(_4\) | CuO | - |
(c) In the contact process for the manufacture of tetraoxosulphate (VI) acid;
(i) State how sulphur (IV) oxide is obtained;
(ii) Write an equation for the reaction that takes place in the catalyst chamber;
(iii) Give the steps required to convert sulphur (VI) oxide to acid.
(d)(i) List two disadvantages of hard water.
(ii) Mention three methods which can be used to remove both permanent and temporary hardness in water at the same time.
(iii) State the role of alum and chlorine respectively in the purification of water for town supply.