Rusting is a process that causes massive destruction of iron structures.

(a) State one condition that accelerates rusting.            (1mk)

(b) State one advantage of rusting.            (1mk)

Carbon (IV) oxide is one of the gases used in fire extinguishers.

(a) State any other possible use of Carbon (IV) oxide             (1mk)

(b) Name any two reagents that can be reacted together to generate Carbon (IV) oxide      (2mks)

When burning magnesium is lowered into a jar containing nitrogen (I) oxide , it continues to burn forming a white solid.

(a) Name the solid                                         (1mk)

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

(a) State Boyle’s law                                           (1mk)

(b) At 400⁰C , 850cm³ of a gas exerts a pressure of 560mmHg. What volume of the same gas would exert a pressure of 640mmHg at the same temperature?             (3mks)

The following equation shows a reversible reaction.

(a) State and explain the observation that can be made when:

i) Temperature is increased.                         (1¹/₂mks) 

ii) Pressure is reduced.                               (1¹/₂mks) 

Some crystals of sugar cane were placed in a test-tube and a few drops of concentrated sulphuric (VI) acid added to it.

i) State what was observed.               (1mk)

ii) What name is given to the property of concentrated sulphuric (VI) acid in (i) above?     (1mk)

iii) Write an equation for the reaction between glucose C₆H₁₂O₆ and H₂SO₄        (1mk)

In the laboratory , hydrogen sulphide gas is prepared by action of dilute hydrochloric acid an metal sulphides.

(a) Name the metal sulphide that can be in preparing the gas.         (1mk)

(b) Write down the equation  for the reaction in (a) above.          (1mk)

(c) Give one chemical test for hydrogen sulphide gas.               (1mk)

(a) State the Boyle’s law.                 (1mk)

(b) A gas occupies 300cm³ at 23⁰C and 100,000Pa. What will be its volume at 0⁰C and 101325Pa?           (2mks)

The empirical formula of a hydrocarbon is C₂H₃. The hydrocarbon has a relative molecular mass of 54.     (H = 1.0 , C = 12.0)

(a) Determine the molecular formula of the hydrocarbon.          (1mk)

(b) Draw the structural formula of the hydrocarbon.         (1mk)

(c) To which homologous series does the hydrocarbon drawn in (b) above belong?   (1mk)

(a) Identify the following cleansing agents.                   (2mks)

(b) State one disadvantage of using the cleansing agent in (a) (ii) above.         (1mk)