If the elements X and Y have atomic numbers 11 and 17 respectively, what type of bond can they form?

• A) Dative
• B) Covalent
• C) Lonic
• D) Metallic

Which group of elements forms hydrides that are pyramidal in structure?

• A. III
• B. IV
• C. V
• D. VI

Consider the reaction represented by the following equation: CuO(s) + H₂SO₄(aq) → CuSO₄(aq) + H₂O(l). Which of the following factors will not affect the rate of the reaction?

• A. Particle size of CuO(s)
• B. Concentration of H₂SO₄(aq)
• C. Temperature of the reacting mixture
• D. Pressure of reaction system

(a)(1) Define each of the following terms: I. deliquescence; II. efflorescence.

(ii) Give one example I substance that undergoes each of the processes in (a)(i).

(b) Outline how three colourless gases suspected to be ethane, ethene and ethyne could be distinguished in the laboratory.

(c)(i) What is water crystallization?

(ii) Hydrated calcium chloride (CaCl\(_2\) = 111, xH\(_2\)O) contains 49.32% water of cystallization. Calm the value of x. [ (CaCl\(_2\) = 111, H\(_2\)O = 18 ]

(d) Name one calcium compound used (i) in the manufactur cement; (ii) as a dessicant; (iii) in the production of plaster of Paris (POP);

(iv) to neutralise acidic soils

(e) A concentrated solution of sodium chloride was electrolysed using graphite electrodes.

(i) State the ions present in the solution

(ii) Name the products at the I. anode, II. cathode.

(iii) Give the by-product of the electrolysis.

For a given solute, the concentration of its saturated solution in different solvents are

• A) the same at the same temperature
• B) different at the same temperature
• C) the same at different temperature
• D) constant

Aluminium containers are frequently used to transport trioxonitrate (V) acid because aluminium

• A) has a silvery-white appearance
• B) has a low density
• C) does not react with the acid
• D) does not corrode

Which of the following results in the fall of acid rain?

• A. Oxides of lead
• B. Particulate matter
• C. Oxides of sulphur
• D. Gaseous hydrocarbon

a)(i) State Graham's law of diffusion.

(ii) Calculate the vapour density of a triatomic gas X if its relative: atomic mass is 16.

(iii) Equal volumes of gases Y and Z are maintained at the same temperature and pressure. If the mass of a molecule of Y is twice that of Z state and explain which of the molecules has the, greater average velocity.

(b) The graph below is the ratio curve for the following reaction carried out in an open vessel.

MgCO\(_{3(s)}\) + 2HCI\(_{(aq)}\) \(\to\) MgCl\(_{2(aq)}\) + CO\(_{2(g)}\) + H\(_2\)\(_{(l)}\).

(i) For how long did reaction occur?

(ii) Why was there a loss in mass?

(iii) State whether reaction rate was fastest at the beginning, the middle or towards the end of the reaction. Give reason for our answer.

(iv) List three reaction conditions that can affect the slope of the curve

(c) Consider the following reaction at equilibrium: PCI\(_{5(g)}\) \(\rightleftharpoons\) PCI\(_{3(g)}\)); \(\Delta\)H = +95 kJmol\(^{-}\)

(i) Write an expression for the equilibrium constant K.

(ii) Predict the effect of the following on the equilibrium position.

I. Increased pressure

II. Increased temperature

III. Removal of chlorine Sketch an energy profile diagram for the forward reaction.

Consider the reaction represented by the equation below: XO + YO → X + YO₂ In the reaction, YO acts as

• A. an acidic oxide
• B. a basic oxide
• C. a reducing agent
• D. a weak base

(a)(i) List four characteristic properties of transition metals

(ii) Name two metals that can be extracted from their ore by electrolysis.

(b)(i) Determine the oxidation number of chromium in Cr\(_2\)O\(^{2-}_{7}\)

(ii) State the colour observed on adding a few drops of dilute tetraoxosulphate (VI) acid to the system representedby the following equation: Cr\(_2\)O\(^{2-}_{7(aq)}\) + H\(_2O_{(l)}\) \(\rightleftharpoons\) 2CrO\(^{2-}_{4(aq)}\) + 2H\(^+_{(aq)}\). Explain your answer.

(c)(i) State and explain what would be observed if hydrogen sulphide gas were bubbled into acidified K\(_2\)Cr\(_2\)O\(_7\). Write an equation for the reaction.

(ii) What precaution should be taken to avoid excessive exposure to hydrogen sulphide gas while it is being generated in the laboratory?