(a) Explain why transition metals
(i) have high melting points
(ii) have variable oxidation states,
(iii) exhibit paramagnetism
(b) (i) Name the impurities present in bauxite
(ii) State how the impurities in bauxite are removed
(ii) Explain why aluminium oxide is said to be amphoteric.
(c) (i) Describe the electrolysis of copper (II) tetraoxosulphate (VI) solution, using copper electrodes.
(ii) Will the colour of the copper (II) tetraoxosulphate (VI) solution change at the end of the electrolysis described in (c)(i) above? Give reasons for your answer.
(a) Write the structural formula of:
(i) 2, 2, 4 - trimethylpentane, (ii) ethylmethanoate, (iii) trans 2, 3 - dimethylbut - 2-ene.
(b) Write the structure of the straight-chain compound that is isomeric with 2,2,4 - trimethylpentane.
(c) Write chemical equations to illustrate the oxidation of: (i) a secondary alkanol (ii) a dihydric alkanol.
(d) When-Crushed cassava was warmed with dilute hydrochloric acid, a sweet-tasting compound, D was obtained. When compcund D was treated with the enzyme, zymase and the mixture distilled a clear and colourleCsliduid, E was obtained. When liquid E was warmed with eth anoic acid i n the presence of a few drops of concentrated tetraoxosulphate (V1) acid, a compound F, with fruity smell was obtained
. (i)To what class of compounds does D belong?
(ii) Name E and F
(iii) Write the fun-ctional group in F
(iv) Write the equation for the reaction between E and ethanoic acid in the presence of concentrated tetraoxosulphate (VI) acid.
(v) Name the type of reaction that takes place between E and ethanoic acid.
(e) Arrange the followingcompounds in their correct order of increasing boiling points: CH\(_3\)CH\(_2\)CH\(_2\)OH, CH\(_3\)CH\(_2\)CH\(_2\)CH\(_2\)CH\(_2\)CH\(_3\) and CH\(_2\)CH\(_2\)CH\(_2\)CH\(_3\); Explain the order.
(a) An element X is represented as \(^{40}_{20} X\)
(i) How many electrons and how many neutrons are present in the atom of X?
(ii) Write the electronic configuration of the atom
(b) Chlorine, whose atomic number is 17, reacts with the element X to form a compound.
(i) What type of bond is formed between X and chlorine?
(ii) Explain how the bond between X and chlorine is formed
(iii) Write the formula of the compound formed and statelhree properties of the compound.
(c) Chlorine has two isotopes of mass numbers 35 and 37 respectively. Suggest the possible relative molar masses of a chlorine molecule.
(d) Calculate the mass of one atom of carbon, given that one mole of carbon weighs 12.0g. (L = 6.02 x 10\(^{23}\))
(a) (i) List the two gaseous fuels produced from coke.
(ii) Which of the two fuels listed in 5(a)(i) is a better fuel?
(iii) Give reasons for your answer in 5(a)(ii)
(iv) Write a balanced equation for the production of each of the fuels. [9 marks]
(b)(i) Differentiate between thermosets and thermoplastics.
(ii) Give one example of:
I. thermosets;
II. thermoplastics.
(iii) State three properties of plastics.
(c)(i) State the method of collecting gases which are denser than air.
(ii) Name two gases that could be used to perform the fountain experiment in the laboratory.
(iii) State the physical properties of the gases named in 5(c)(ii) which makes them suitable for the experiment. [4 marks]
(d) (i) State two compounds that could be used to test for water.
(ii) Give three disadvantages of hard water.
1. (a ) Define the term compound.
(b) State two conditions necessary for the cracking of petroleum fractions.
(c) Name two transition elements that are used as catalyst.
(d) (i) Write an equation for the reaction between zinc dust and trioxonitrate (V) solution.
(ii) Which of the reactants in 1(d)(i) is:
I. reduced;
II. oxidized.
(e) Two isotopes of oxygen 16O and 18O have relative abundance of 90 % and 10 % respectively. Calculate the relative atomic mass of oxygen.
(f) List two ores of iron.
(g) (i) What is biotechnology?
(ii) Name one product that can be obtained using biotechnology.
(h) Define the term element.
(i) State two sources of methane in the atmosphere.
(j) Explain briefly why the trend of the boiling points for group VII elements is in the order I\(_2\) > Brl\(_2\)> Cl\(_2\).
