CHEMISTRY FORM FOUR PRE NECTA-SOLVED EXAMINATION 2026 – JEGOS
QUESTIONS
4. (a) Explain why:
(i) Burning a fuel containing Sulphur as an impurity causes acid rain.
(ii) The presence of too much Sulphur dioxide in the atmosphere has a damaging effect on many buildings made of marble (calcium carbonate).
(b) Sulphur dioxide gas is bubbled through acidified potassium permanganate solution. Using the information provided:
(i) Write the balanced molecular equation for the reaction.
(ii) Identify the type of chemical reaction involved.
(iii) Write the ionic equation for the reaction in (i). (iv) State the colour change observed during the reaction.
5. (a) Which specific separation technique would be most effective to isolate or extract the components of each of the following mixtures?
(i) A mixture of ammonium chloride and sodium chloride.
(ii) A mixture of petrol and diesel from crude oil.
(iii) Fine clay particles suspended in muddy river water.
(iv) Natural pigments from green spinach leaves.
(v) Pure water from a highly concentrated copper(II) sulphate solution.
(vi) Clear honey from pieces of beeswax. (b) Briefly explain three specific industrial or clinical applications of paper chromatography in daily life.
