a)They are readily oxidized by atmospheric oxygen when exposed to air.

wrong symbols

(a). Effervescence occurs, due to production of carbon (IV) oxide½ since lemon juice is acidic.½ 2

(b). No effervescence½ copper is below hydrogen in the activity series and therefore does not ½ displace hydrogen.

(a). A –Lead nitrate / Pb (NO3)2 1

D – Zinc sulphate /Zn SO4 1

C - Distilled water 1

(a). Weak acid – one that dissociates /ionises partially in water.

Strong acid – one that dissociates /ionises completely in water. 3

(b). Rapid effervescence occurs in strong acid but slow in weak acid.

Add dilute acid to each substance separately. produces which has a chocking smell/turns potassium dichromate paper from orange to green.

which has no smell /turns lime water turbid /forms a white precipitate.

(a). A white precipitate is formed.

has a giant ionic½ structure in which ions are held together by strong electrostatic attraction while PCl3 has simple molecular structure ½ in which molecules are held together by weak van der waal’s forces.

Has one electron in its outer most energy level which it can lose to form an ion with (H+)+ charge and can also gain to form an ion with with

(a). Substitution chlorination

A black precipitate of lead sulphide is formed.

(b). A – represents the solvent front.

(c). Application of chromatography:

- In pharmaceutical industry to control quality of drugs.

-Food industry to determine acceptable food colours.

-In research and quality control of foodstuffs, by standard bodies.

-Analyzing blood samples to determine use of illegal drugs by sportsmen /women

-To nitric acid add excess of ½lead (i) carbonate.

-Filter to obtain lead (ii) nitrate solution as filtrate.½

-Add dilute hydrochloric acid to lead (ii) nitrate.½

-Filter to obtain lead (ii) chloride solid.½

(a). When gases react, they do so in volumes which bear a simple whole number ratio to one another and to the volume of the product if gaseous.

(a). Nitrogen (1) oxide.

(b).Withdraw delivery tube from water to prevent sucking back.½ OR – Stop heating while ½ some ammonium nitrate still remains to avoid an explosion.

(a).To force the molten sulphur and water up

(b). 1700C10 atm

(a). Gases which prevent dispation of heat across the atmosphere resulting in increased atmospheric temperatures. 3

(b). Chlorine is a component of CFC’S½

When released to the atmosphere, they breakdown ½ into chlorine and flourine atoms. The free atoms under the influence of½ U.V. light accelerate the disintegration of the ozone layer.½

Mixture turns brown /intensity of brown colour increases. Addition of H+ reduces ½the concentration of OH- ions shifting equilibrium to the left.½