(a) Name two allotropes of sulphur             (2mks)

 (b) In an experiment to investigate a certain property of sulphur, Maina added few drops of conc HNO3 to sulphur in a test tube and warmed the mixture

i) State one observation made                     (1mk)

ii) Write a chemical equation of the reaction that occurred (1mk)

A hydrocarbon can be represented as: C₂H₂

(a) Name the hydrocarbon       (1mk)

(b) State two reagents that can be reacted together to generate the hydrocarbon       (2mks)

(c) Identify the group of hydrocarbons into which C₂H₂ belongs to      (1mk)

The reduction potentials of elements M and N are;

Using the above reduction potentials, predict whether a reaction would occur between N⁺_(aq) and M_(s) (3mks)

(a) Define the term half-life                            (1mk)

(b) Name two particles likely to be emitted when a radioactive nuclide undergoes radioactivity    (2mks)

(c) The half-life of a radioactive nuclide is 3 hours. Given that its initial mass is 288g, determine the remaining mass after 12 hours.                 (2mks)

During the electrolysis of dilute copper (II) chloride using carbon electrodes, a current of 1.5A was passed through the solution for 2 hours and 30 minutes

(a) Write the ionic equation of the reaction that occurred at the cathode (1mk)

(b) Given R.A.M of copper = 64 and 1F = 96500C, calculate the change in mass of the cathode (3mks)

(a) Define the term , dynamic equilibrium               (1mk)

(b) A reaction at equilibrium can be represented as

State and explain the observation made when;

i) NaOH is added to the equilibrium mixture           (2mks)

ii) HCl is added to the equilibrium mixture                  (2mks)

A reaction can be represented as;

Given that the bond energies of C-H , C=C , C-C , C-Br and H-Br as 20Kj/mol , 580Kj/mol , 446Kj/mol , 438Kj/mol and 396Kj/mol respectively. Determine the heat of formation of C₂H₅Br.                 (3mks)

A polymer can be represented as.

(a) Name and draw the structure of the monomer.         (2mks)

(b) What type of polymerization is the above case?        (1mk)

(b) Given that the molecular mass of the polymer is 25620, how many units of the monomer make the polymer (2mks)

Explain why molten sodium chloride conducts electricity , but solid sodium chloride does not.     (2mks)

At 60⁰C , 38 grams of lead (II) nitrate saturate 56cm³ of water. Determine the solubility of lead (II) nitrate at this temperature.         (2mks)