(i) Boyle's law states that the volume of a given mass of gas is inversely proportional to its pressure if the temperature remains constant.
(ii) P \(\propto\) 1 or PV = K or V \(\propto\) \(\frac{1}{P}\)
(iii)

\(\frac{P_1V_1}{T_1} = \frac{P_2V_2}{T_2}\)
\(V_2 = \frac{P_1V_1T_2}{P_2T_1}\)
\(V_2 = \frac{6.5 \times 10^4 \times 500 \times 273}{(273 + 30) \times 1.01 \times 10^5}\)
\(V_2 = 290 cm^3\)

(c) An inflated balloon expands in warm water because in air, particles in the balloon acquire more kinetic energy. There is an increase in the pressure inside the balloon. In order to keep the pressure constant the balloon expands.
(d) (i) Vapour density is the number of times a given volume of a gas or vapour is as heavy as an equal volume of hydrogen gas at the same temperature and pressure.
(ii) molar mass of SO\(_2\) = 32 + 16 x 2 = 64g mol\(^{-1}\).
Vapour density x 2 = relative molar mass
Vapour density = \(\frac{64}{32}\)
= 32

(e) (i) I. upward delivery = NH\(_3\)
II. downward delivery = SO\(_2\)
(ii) I. acidic II. basic/alkaline
(iii) SO\(_2\) – oxidizing agent NH\(_3\) - reducing agent.

(f) (i) – bronze – typemetal – soft solder
(ii) bronze – for making coins, - metals/other ornaments
typemetal – for printing
soft solder – for plumbing/welding.