(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.
(a) Nucleons are the particles found in the nucleus of an atom, that is, the protons and neutrons.
(b) Graham's law of diffusion: at constant temperature and pressure, the rate of diffusion of a gas is inversely proportional to the square root of its density (or of its molar mass).
\[\text{rate} \propto \frac{1}{\sqrt{\rho}}\]
(c) Aluminium does not corrode easily because it forms a thin, tough, coherent and impervious layer of aluminium oxide on its surface. This oxide layer sticks firmly to the metal and prevents air and moisture from reaching the metal underneath, protecting it from further attack.
(d) Three periodic properties: atomic radius, ionization energy and electronegativity (electron affinity and metallic/non-metallic character are also acceptable).
(e) Two reasons real gases deviate from ideal behaviour:
- The molecules of a real gas have an appreciable (finite) volume, which is not negligible compared with the volume of the container, especially at high pressure.
- There are intermolecular forces of attraction between real gas molecules, especially at high pressure and low temperature.
(f) Three industrial uses of fractional distillation: refining of crude petroleum into its various fractions; separation of liquid air into oxygen and nitrogen; separation of ethanol from a water-ethanol mixture (rectification of spirits).
(g) Factors that determine selective discharge of ions during electrolysis: the position of the ion in the electrochemical (discharge) series, the concentration of the ion in the electrolyte, and the nature of the electrode used.
(h) Types of reaction:
- (i) \(C_2H_6 + Br_2 \rightarrow C_2H_5Br + HBr\) is a substitution reaction.
- (ii) \(C_2H_4 + Br_2 \rightarrow C_2H_4Br_2\) is an addition reaction.
(i) When butane burns in a limited supply of air, incomplete combustion occurs, giving carbon(II) oxide (and carbon/soot) and water vapour.
(j) Three methods of separating a solid from a liquid: filtration, evaporation and decantation (centrifugation and crystallization are also acceptable).
(a) Nucleons are the particles found in the nucleus of an atom, that is, the protons and neutrons.
(b) Graham's law of diffusion: at constant temperature and pressure, the rate of diffusion of a gas is inversely proportional to the square root of its density (or of its molar mass).
\[\text{rate} \propto \frac{1}{\sqrt{\rho}}\]
(c) Aluminium does not corrode easily because it forms a thin, tough, coherent and impervious layer of aluminium oxide on its surface. This oxide layer sticks firmly to the metal and prevents air and moisture from reaching the metal underneath, protecting it from further attack.
(d) Three periodic properties: atomic radius, ionization energy and electronegativity (electron affinity and metallic/non-metallic character are also acceptable).
(e) Two reasons real gases deviate from ideal behaviour:
- The molecules of a real gas have an appreciable (finite) volume, which is not negligible compared with the volume of the container, especially at high pressure.
- There are intermolecular forces of attraction between real gas molecules, especially at high pressure and low temperature.
(f) Three industrial uses of fractional distillation: refining of crude petroleum into its various fractions; separation of liquid air into oxygen and nitrogen; separation of ethanol from a water-ethanol mixture (rectification of spirits).
(g) Factors that determine selective discharge of ions during electrolysis: the position of the ion in the electrochemical (discharge) series, the concentration of the ion in the electrolyte, and the nature of the electrode used.
(h) Types of reaction:
- (i) \(C_2H_6 + Br_2 \rightarrow C_2H_5Br + HBr\) is a substitution reaction.
- (ii) \(C_2H_4 + Br_2 \rightarrow C_2H_4Br_2\) is an addition reaction.
(i) When butane burns in a limited supply of air, incomplete combustion occurs, giving carbon(II) oxide (and carbon/soot) and water vapour.
(j) Three methods of separating a solid from a liquid: filtration, evaporation and decantation (centrifugation and crystallization are also acceptable).
