(a) (i) State three characteristic properties of transition metals.

(ii) What is the oxidation state of manganese In each of the following species? (1) MnCl\(_2\) (II) MnO\(_2\) (III) MnO\(_4^{-}\)

(iii) Explain why manganese conducts electricity in the solid state but manganese chloride conducts only when molten or in solution.

(b)(i) The collision theory suggests that for two particles to react, they must collide. What two factors determine whether or not the collision would lead to formation of products?

(ii) Use an energy profile diagram to illustrate what is meant by the enthalpy change (\(\Delta\)H) and the activation energy (E\(_A\)) of a reaction.

(c) When few drops of aqueous KSCN are added to a solution of iron (III) salt the following equilibrium is set up:

Fe\(^{3}_{(aq)}\) + 3SCN\(^{-}_{(aq)}\) \(\rightleftharpoons\) Fe(SCN)\(_{3(aq)}\) 

yellow       colourless               deep red

The equilibrium mixture has a pale red colour.

(i) Explain what would happen if more KSCN\(_{(aq)}\) were added to the equilibrium mixture.

(ii) Which of the ions in the equilibrium mixture forms an insoluble hydroxide with NaOH\(_{(aq)}\)? Write an equation for the reaction
(iii) State two changes observed on adding NaOH\(_{(aq)}\) to the equilibrium mixture.

(a) i) An organic compound X contains 40% carbon, 6.67% hydrogen, the rest being oxygen. If X has a relative molecular mass of 60, determine its

(i) empirical formula (ii) molecular formula. [H = 1 ; C = 12; O = 16]

(b) An alkanoic acid Y has a relative molecular mass of 74.

(i) State the functional group of Y

(ii) What t of reaction is involved when Y is converted to an alkanoate?

(iii) Determine the structural formula of Y.

(iv) Write an equation for the reaction between Y and sodium

(v) If X in (a) above boils at 118°C and belongs to the same homologous series as Y, state with reason, whether the boiling point of Y will be equal to, higher or lower than 118°C.

(c)(i) What is fermentation?

(ii) Write an equation for the fermentation of glucose.

(iii) What must be added to glucose solution to make it ferment?

(iv) Explain why a tightly corked grass bottle filled to the brim with fresh palm wine shatters on standing.

(a)Give two reasons why aluminium is preferred to copper for making overhead electric cables.

(ii) Describe briefly the electrolytic extraction of aluminium from purified bauxite.

(b) The diagram below represents an electrolytic cell used for the purification of copper.

(i) Which of the electrodes I and II increases in mass during the electrolysis? Give reasons for your answers

(ii) State with reason the site of oxidation

(iii) Identify III and explain why its colour does not change in intensity during the electrolysis.

(c) Calculate the current in amperes that will deposit 8.00 g of calcium from used CaCl\(_2\) in 1 hour 15 minutes. [Ca = 40.0; 1 Faraday = 96500C]

(a) Mention one oxide in each case, which

(i) used in bleaching

(ii) is a redish-brown gas

(iii) reacts with NaOH and also with HCI;

(iv) dissolves in water to give a solution with pH greater than 7;

(v) oxidizes hot, concentrated HCI to chlorine

(b)(i) State three methods that can be used to removo hardness in a sample of water that contains calcium hydrogentrioxocarbonate (IV).

(ii) Explain with the aid of appropriate equation, why it is not advisable to build a house with limestone in an environment polluted by sulphur (IV) oxide.

(c)(i) List two compounds of potassium which yield oxygen when heated strongly

(ii) Calculate the amount (in moles) of gas which occupies 250 cm\(^3\) at s.t.p. [1 mole of gas occupies 22.4 dm\(^3\) at s.t.p]

(iii) If 250 cm\(^3\) of a gas at s.t.p. is heated to 27°C at constant pressure, calculate its new volume.

(iv) Explain in terms of the collision theory what happens as a gas is heated at constant pressure.

(a) State the role of each of the following substances in the treatment of river water for town supply (i) Sand bed. (ii) Alum (iii) Chlorine

(b)(i) Give three major uses of H\(_2\)SO\(_4\)

(ii) Explain the following observation: A strip of blue litmus paper dropped into concentrated H\(_2\)SO\(_4\) becomes charred whereas in dilute H\(_2\)SO\(_4\), it turns red and is not charred.

(iii) Write an equation to show how concentrated H\(_2\)SO\(_4\) reacts with zinc.

(c)(i) List two gaseous pollutants that can be generated by burning coal.

(ii) Explain why coal burns more easily when it is broken into pieces than when it is in lump form.

(ii) What gas is responsible for most of the explosions in coal mines?

(iv) Name: the non-volatile residue left behind after the destructive distlillation of coal

(d)(i) What is meant by allotropy?

(ii) Name two crystalline allotropes of carbon

(iii) Name two elements apart from carbon, which exhibit allotropy

(iv) It is now known that carbon has an allotropic form called fullerene, containing molecules of formula C\(_{60}\). Calculate the mass of one mole of these molecules [C = 12]