(a)(i) What is meant by hydrocarbons?

(ii) A hydrocarbon consists of 92.3% carbon. If it's vapour density is 39, determine its molecular formula. (H = 1; C = 12)

(b)(i) Outline a suitable laboratory procedure for obtaining ethanol from cassava tubers

(ii) List two laboratory reagents used for oxidizing ethanol to ethanoic acid.

(c) What name is given to each of the following processes?:

(i) Conversion of alkanols to alkanoates;

(ii) Breakdown of proteins to amino acids;

(iii) Conversion of oils to fats

(iv) Alkaline hydrolysis of fats and oils.

(a)(i) Determine the maximum number of electrons that can occupy the principal energy level M of an atom.

(ii) Show the changes in the electronic structures of atoms of sodium and fluorine (\(^{23}_{11}\)Na: \(^{19}_{9}F\)) when they combine to form sodium fluoride.

(iii) State: three properties that sodium fluoride would have, based a-n the bond type present in the compound.

(b) Write equations to show  when:

(i) sodium metal burns in limited supply of oxygen;

(ii) water is added to the product in (b)(i) above

(c) Describe a suitable laboratory procedure for comparing the conductance of 1 mol dm\(^{-3}\) aqueous solutions of sodium hydroxide and ethanoic acid.

(a) (i) Define heat of combustion.

(ii) What name is given to the container used for determining tne reaction?

(b) The heat of combustion of carbon in excess air is - 3935 kJ.

(i) Sketch an energy profile diagram for the reaction.

(ii) Calculate the heat change when 60 g of carbon undergoes complete combustion to produce carbon (IV) oxide. (C = 12)

(iii) Explain why the value of the heat of neutralization of strong acids by strong bases is constant.

(c) Give reason for the following:

(i) rusting of iron is regarded as a slow combustion process;

(ii) iron filings rust much more faster than iron nails when exposed to the same atmospheric condition;

(iii) iron is better protected from corrosion by plating it with.zinc than with tin

Classify each of the following as physical change or a chemical change:

(a) fractional distillation of liquefied air;

(b) cracking of petroleum fractions;

(c) conversion of rhombic sulphur to monoclinic sulphur;

(d) chromatographic separation of chlorophyll.

(a) Give one disadvantage of:

(i) hard water

(ii) soft water

(b) Explain why the degree of hardness in a sample of clear lime water is higher than in another sample has that been turned milky by carbon (IV) oxide.