(a) What are nucleons? (b) State Graham's law of diffusion. (c) Explain briefly why aluminium does not corrode easily. (d) State three examples of periodic properties. (e) State two reasons why real gases deviate from ideal gas behaviour. (f) List three uses of fractional distillation in industry. (g) What factors determine the selective discharge of ions at the electrodes during electrolysis? (h) State the type of reaction represented by each of the following equations: (i) C\(_2\)H\(_6\) + Br\(_2\) ---> C\(_2\)H\(_5\)Br + HBr; (ii) C\(_2\)H\(_4\) + .Br\(_2\) ---> CH\(_4\)Br\(_2\)
(i) Name the products formed when butane burns in limited supply of air. (j) List three methods of separating a solid from a liquid.
Explanation
(a) Nucleons refer to the protons and neutrons that are found in the nucleus OR Nucleons are nuclear particles which are protons and neutrons. (b) Graham's law of diffusion states that, at constant temperature and pressure, the rate of diffussion of a gas is inversely proportional to the square root of its density or molar mass or vapour density (c) Aluminum oxide layer forms on the surface of the metal. The oxide layer forms a potective coating layer which does not flake off. (d) — atomic radius, Ionic radius, ionization energy. —redox potentials, electronegativity, electron affinity. — melting point, boiling point, electrical conductivity. (e) — Molecules of real gases have significant attractive forces between them. — The volume of the molecules of real gases is not negligible. --- Collision between the molecules are not perfectly elastic.
(f) — Separation of crude oil into its components / petroleurn refining. —Purification of ethanol. —Separation of liquefied air (g) —Position of the ions in the electrochemical series —Concentration of the ions in the electrolyte —Nature of the electrodes used. (h)(i) Substitution reaction. (ii) Addition reaction. (i) — Carbon or soot, Carbon two oxide (carbon II oxide), Water. (j) Filtration, Crystallisation, Evaporation, decantation, centrifugation
