Waec Chemistry 1993 Past Questions and Answers

Question 41:

• WAEC 1993

Mention the respective properties of the following allotropes of carbon that account for their uses as indicated:
(a) diamond used for drilling rocks;
(b) diamond used as jewels;
(c) graphite used as electrodes;
(d) graphite used for slowing down neutrons in nuclear reactors;
(e) wood charcoal used in gas masks.

Question 42:

• WAEC 1993

State which of the following can exhibit geometric isomerism:

Give reason for your answer

Question 43:

• WAEC 1993

(a) X and Y belong to the same period in the Periodic Table is a group I element while Y belongs to group VII. State which of the elements would
(i) be a good oxidizing agent
(ii) have the smaller atomic volume
(iii) have the higher ionization potential
(b) Explain your answer in (a)(i) above.

Question 44:

• WAEC 1993

The compound whose formula is written below is a major component of a soft fatty substance:

(a) State the change that would be observed in the physical state of the fatty substance if hydrogen were bubbled through it for long time in the presence of finely divided nickel at about 180\(^o\)C
(c) Determine the amount (in mole) of hydrogen that would be consumed if one mole of the component reacted completely with hydrogen.
(c) State the product of the reaction of the fatty substance with hot concentrated sodium hydroxide solution

Question 45:

• WAEC 1993

(a)(i) Distinguish between a strong acid and a concentrated acid.
(ii) What is meant by amphoteric oxide? Give one example.

(b)(i) Describe the manufacture of tetraoxosulphate (VI) acid by contact process.
(ii) Write one equation each to show the action of tetraoxosulphate (VI) acid respectively as a dehydrating agent and as an oxidizing agent.
(iii) Give the reason why tetraoxosulphate classified as a heavy chemical.