• A-Gamma rays
• B-Beta rays
• C-Alpha rays

​An experiment was carried out to prepare crystals of magnesium sulphate. Excess magnesium powder was added to 100 cm3 of dilute sulphuric (VI) acid in a beaker and warmed until no further reaction took place. The mixture was filtered and the filtrate evaporated to saturation, then left to cool for crystals to form.
(a) (i) Write an equation for the reaction. 
(ii) Explain why excess magnesium powder was used. 
(iii) State how completion of the reaction was determined. 
(iv) What is meant by a saturated solution? 
(v) Explain why the filtrate was not evaporated to dryness. 
(b) When bleaching powder, CaOCl2, is treated with dilute nitric(V) acid, chlorine gas is released. This reaction can be used to determine the chlorine content of various samples of bleaching powders and liquids.
(i) Write an equation for the reaction of nitric(V) acid with bleaching powder.
(ii) Calculate the volume of chlorine produced when 10g of CaOCl2 is treated with excess nitric (v) acid. (Ca = 40.0; 0 = 16.0; Cl = 35.5; 1 mole of gas occupies 22.4dm3 at s.t.p) 
(c) Apart from use of chlorine gas in bleaches and water treatment, state two other uses of chlorine gas.

​(a) Complete Table I by indicating the observations, type of permanent or temporary change and name of new compound formed.

(b) Use the set-up in Figure 3 to answer the questions that follow. The flask was covered with a cloth that had been soaked in ice-cold water.

(i)State the observation made on the coloured water. Explain.
(ii) Name the gas law illustrated in Figure 3. 
(c)Use the standard electrode potentials in Table 2 to answer the questions that follow.

​(i)Write the half-cell representation for the element whose electrode potential is for hydrogen. 
(ii) Arrange the elements in order of reducing power, starting with the weakest reducing agent. 
(iii) I Select two half cells which combine to give a cell with the least e.m.f. 
II Calculate the e.m.f of the half cells identified in (iii) I. 

The diagram in figure I shows some natural and industrial processes. Study it and answer the questions that follows

​(a) Identify the processes labelled: 
A...................
B...................
C...................
D...................
(b) State the reagents and conditions required for processes B and D.
(i) Process B:
Reagent................
Conditions ............ 
(ii) Process D:
Reagent................
Conditions ............ 
(iii) Describe how process D is carried out.
(iv) State two additives used to improve the quality of soap.
(c) State the reagents required in steps F and G.
(iii) Draw the structure of terylene.
(d) (i) Name the polymer formed in step C.
(ii) State one disadvantage of the polymer formed in (d) (i).

 (a) Name two ores of iron. 
(b) Describe how the amount of iron in a sample of iron(III) oxide can be determined. 

(a) Give the symbols of the o charged particles emitted by a radioactive isotope.

​mass number 
atomic number:

(a) Define molar heat of displacement. 
(b)The following ionic equation represents the reaction between metal Y and an aqueous solution of Z2+.

Draw an energy level diagram to represent the reaction

Metal X and Y have standard electrode Potentials of —0.13 V and —0.76V respectively .The metals were Connected to form a cell as shown in Figure 4.

(a) Name the part labelled z. 
(b) State one functi0 of the part labelled Z. 
(c) Calculate the e.m.f. of the cell. 

 In the Haber process, nitrogen reacts with hydrogen according to the following equation.

(a)What would be the effect of adding a catalyst on the position of the equilibrium? 
(b) Explain why it is not advisable to use temperatures higher than 773 K in the Haber process.

 Study the flow chart in Figure 1 and answer the questions that follow.

Gas N forms a while suspension with aqueous calcium hydroxide.
(a) Name the anion present in the potassium salt. 
(b) Write an ionic equation for the formation of solid M. 
(c) Give one use of gas N.

 The following are formulae of organic compounds. Use the formulae to answer the questions that follow:

​(a) Select:
(i) two compounds which when reacted together produce a sweet smelling compound.
(ii) an unsaturated hydrocarbon. 
(b) Name the compound selected in (a) (ii).

(a) Define a soluble base. 
(b) Aqueous solutions of 2M ethanoic acid and 2M nitric(V) acid were tested for electrical conductivity. Which solution is a better conductor of electricity? Explain.

The decay rates of a sample of a radioisotope of bismuth at different time intervals is indicated in the following table.

(a)(i) Draw a graph of disintegration rate against time. 
(ii) Determine the half-life of bismuth. 
(iii) What would be the effect on the curve if half the amount of sample of bismuth were used. 
(b) Radioactivity has several applications. State one application of radioactivity in: 
(i) Medicine 
(ii) Agriculture 
(iii) Tracers 
(iv) Nuclear power station 
(c) State two dangers associated with radioactivity. 

The following steps were used to analyse a metal ore.
(i) An ore of a metal was roasted in a stream of oxygen. A gas with a pungent smell was formed which turned acidified potassium dichromate(VI) green.
(ii) The residue left after roasting was dissolved in hot dilute nitric(V) acid. Crystals were obtained from the solution.
(iii) Some crystals were dried and heated. A brown acidic gas and a colourless gas were evolved and a yellow solid remained. (iv) The solid was yellow when cold.
(v) The yellow solid was heated with powered charcoal. Shiny beads were formed.
Name the:
(a) gas formed when the ore was roasted in air. 
(b) gases evolved when crystals in step (iii) were heated. 
(c) yellow solid formed in step (iii). 
(d) shiny beads in step (iv). 
(e) The yellow solid from procedure (iii) was separated, dried, melted and the melt electrolysed using graphite electrodes.
I. Describe the observations made at each electrode. 
II. Write the equation for the reaction that took place at the anode. 
(f) Some crystals formed in step (ii) were dissolved in water, and a portion of it reacted with potassium iodide solution. A yellow precipitate was formed. Write an ionic equation for this reaction. 
(g) To another portion of the solution from (f), sodium hydroxide solution was added drop by drop until there was no further change. Describe the observation made. 
(h) To a further portion of the solution from (f), a piece of zinc foil was added.
I. Name the type of reaction taking place. 
II. Write an ionic equation for the above reaction.

W is a colourless aqueous solution with the following properties:

• I It turns blue litmus paper red.
• II On addition of cleaned magnesium ribbon, it gives off a gas that burns with a pop sound.
• III On addition of powered sodium carbonate, it gives off a gas which forms a precipitate with calcium hydroxide solution.
• IV When warmed with copper(II) oxide powder, a blue solution is obtained but no gas is given off
• V On addition of aqueous barium chloride, a white precipitate is obtained.

(a) (i) State what properties (I) and (III) indicate about the nature of W. 
(ii) Give the identity of W. 
(iii) Name the colourless solution formed in (II) and (III). 
(iv) Write an ionic equation for the reaction indicated in (V).
(b) Element V conducts electricity and melts at 933K. When chlorine gas is passed over heated V, it forms a vapour that solidifies on cooling. The solid chloride dissolves in water to form an acidic
solution. The chloride vapour has a relative molecular mass of 267 and contains 19.75% of V. At a higher temperature, it dissociates to a compound of relative molecular mass 133.5. When aqueous
sodium hydroxide is added to the aqueous solution of the chloride, a white precipitate is formed which dissolves in excess alkali. (V = 27.0 ; CI = 35.5)
(i) Determine the:

• I empirical formula 
• II molecular formula 

(ii) Draw the structure of the chloride vapour and label the bonds. 
(iii) Write an equation for the reaction that form a white precipitate with sodium hydroxide. 

The conductivity of some substances was investigated. The observations made were recorded in
Table 1. Use it to answer the questions that follow.

​(a) (i) Identify a substance that is a metal. Give a reason.
(ii) Substance F does not conduct electricity in solid state but conducts in molten or aqueous state.
Explain. 
(b) Copper(II) sulphate solution was electrolysed using the set up in Figure 1.

​(i) State the observations made during electrolysis. 
(ii) Write the equation for the reaction that occurs at the anode.
(iii) State the expected change in pH of the electrolyte after electrolysis. 
(c) The experiment was repeated using copper electrodes instead of carbon electrodes.
Describe the observations made at each electrode. 
(d) Electroplating is an important industrial process.
What is meant by electroplating. 
(iii) During electroplating of an iron spoon, a current of 0.6 amperes was passed through aqueous silver nitrate solution for 1 1/2 hours. Calculate the mass of silver that was deposited on the spoon. 
(Ag = 108.0 ; I F = 96,500 C /mol)

(a) Name the homologous series represented by each of the following general formulae.

(i) Give the physical state of compound G at room temperature. 
(ii) G is completely hydrolysed by heating with aqueous sodium hydroxide.
I Give the structural formula of the alcohol formed. 
II Write a formula for the sodium salt formed. 
III State the use of the sodium salt.
(c) Ethyne is the first member of the alkyne family.
(i) Name two reagents that can be used in the laboratory to prepare the gas. 
(ii) Write an equation for the reaction. 
(d) Perspex is an addition synthetic polymer formed from the monomer,

​(i) What is meant by addition polymerisation? 
(ii) Draw three repeat units of perspex. 
Give one use of perspex 
(iv) State two environmental hazards associated with synthetic polymers. 

(a) Name two ores in which sodium occurs. 
(b) During extraction of sodium using the down's process, calcium chloride is added to the ore.
Give a reason for the addition of calcium chloride. 
(c) State two uses of sodium.

(a) What is an inert electrode? 
(b) State the products formed when brine is electrolysed using inert electrodes. 
Anode: 
Cathode: 

The following procedure was used to investigate the temperature changes that occur when sodium hydroxide solution is added to dilute hydrochloric acid.
(i) Place the acid in a glass beaker and record its temperature.
(ii) Add a known volume of sodium hydroxide solution.
(iii) Stir the mixture and record the highest temperature reached.
(iv) Repeat steps
(ii) and
(iii) with different volumes of sodium hydroxide solution.
(a) State two factors that must be kept constant in this experiment 
(b) Explain how the use of a polystyrene cup will affect the results. 

Copper(II) ions react with excess aqueous ammonia to form a complex ion.
(a) (i) Write an equation for the reaction that forms the complex ion. 
(ii) Name the complex ion. 
(b) Explain why CH4 is not acidic while HCl is acidic yet both compounds contain hydrogen. 

​(a) State one characteristic of a reaction where equilibrium has been attained. 

A sample of water is suspected to contain sulphate ions. Describe an experiment that can be carried out to determine the presence of sulphate ions. 

The diagram in Figure 1 shows a section of a dry cell. Study it and answer the questions that follow.

​(a) Name the part labelled B. 
(b) The part labelled A is a paste. Give a reason why it is not used in dry form. 
(c) What is the purpose of the zinc container?