a. A compound contains 52.2% C, 13.1 % H and Oxygen only. The vapour density of the compound is 23.
    Determine i. its empirical formula; ii. its molecular formula,  [H=1.0, C=12.0, O= 16.0]

iii1). The compound reacts with sodium metal to produce hydrogen gas and when warmed with acidified \(KMnO_{4(aq)}\) gives a solution that turns from purple to colorless. It also forms a sweet-smelling liquid when heated with ethanoic acid  in the presence of concentrated \(H_2SO_4\)
 name the functional group present in the compound; iii2). draw the structural formula of the compound.

b. Outline the chemical equations for the production of ethanol from cooked cassava.

ci. Explain briefly why a piece of aluminum does not react with water.

ii. How can a pure sample of aluminum chloride crystals be prepared from aluminium

d. Describe how water can be separated from aqueous \(CuSO_4\)

a. Starting with calcium chloride, describe briefly how a solid sample of calcium trioxocarbonate (IV) can be prepared in the laboratory.

b. With relevant equations outline the procedure for the purification of impure copper.

c. Copper reacts with concentrated trioxonitrate (V) acid:  i. write a balanced chemical equation for the reaction;

ii. state what would be observed in the reaction,

iii. state why the copper is oxidized;

iv. an excess of copper is added to 25.0 \(cm^3\) of 16.0 mol \(dm^3\) \(HNO_3\). Calculate the volume of the gas formed at s.t.p. [H=1.0, N=14.0, O= 16.0, Cu=63.0; Molar volume of gas at .s.t.p.=22.4 \(dm^3\)]

di. Pure \(HNO_3\), is a colourless liquid but when exposed to air, it turns yellowish-brown in colour. Explain briefly this observation.

ii. Write a balanced equation for the laboratory preparation of hydrogen trioxonitrate (V) acid.

a. Describe how iron and aluminum reacts with each of the following substances: i.  dilute \(H_2SO_4\); ii.   dilute \(HNO_3\)

bi. Write an equation for the burning of sulphur in air.

ii. Name the catalyst used in the contact process.

iii. In the contact process, why is an excess of air used?

iv. Why is it necessary to cool the catalyst used in 5(b)(ii)?

v. Give a reason why the air used in the contact process needs to be as clean as possible.

vi. State two reasons why SO2 should not be discharged into the atmosphere.

ci. State the reagents and conditions used in the laboratory preparation of chlorine.

ii. State two uses of chlorine.

di. Name the drying agents for each of the following gases: 1. Hydrogen; 

i2.  sulphur (IV) oxide; 

i3. Ammonia.

ii1. State the components of the following
      Bronze;  ii2. Brass.