Chemistry 1991 Waec Past Questions and Answers

Question 36 :

• WAEC 1991

Which of the following is suitable for determining different isotopes present in an element which exhibits isotopy?

A. Sensitive weighing balance
B. Cathoda ray tube
C. Mass spectrometer
D. Geiger muller counter
E. Eudiometer

Question 37 :

• WAEC 1991

State the atoms represented as shown below:

(a) State the relationship between the two atoms.
(b) What is the difference between them?
(c) Give two examples of elements which exhibit the phenomenon illustrated above.

Question 38 :

• WAEC 1991

(a)State three characteristics of a catalyst.
(b) Mention one manufacturing process in which each of the following metals is used as a catalyst:
(i) iron;
(ii) nickel;
(iii) platinum
(c) Give one example of an organic catalyst.

Question 39 :

• WAEC 1991

A colourless and odourless gas X burns in oxygen with a pale blue flame.
(a) Suggest two gases which X could be.
(b) Give one chemical test that could be used to confirm which of the two gases X is.

Question 40 :

• WAEC 1991

Methane is obtained when a powdered mixture of anhydrous sodium ethanoate and soda-lime is heated in a hard glass test tube.
(a) Write an equation for the reaction.
b) Explain briefly why soda-lime is preferred to sodium hydroxide for the preparation.