Waec Chemistry 1993 Past Questions and Answers

Question 21:

• WAEC 1993

The component of air that removed when air is bubbled into alkaline pyrogallol solution is

A. Carbon(lV) oxide
B. Oxgyen
C. Water vapour
D. Nitrogen
E. Helium

Question 22:

• WAEC 1993

Which of the following will not affect the degree of hardness in a sample of temporarily hard water?

A. Addition of washing soda
B. Adding of soap
C. Treatment with carbon exchange resin
D. Filtration
E. Distillation

Question 23:

• WAEC 1993

Examples of polymers include the following except

A. Starch
B. Nylon
C. Wool
D. Perspex
E. Glass

Question 24:

• WAEC 1993

When the trioxonitrate (IV) salt of an alkali metal Y is heated, the formula of the residue is

A. Y₂O
B. YNO₂
C. Y₂O₃
D. Y (NO₂)₂
E. YO₂

Question 25:

• WAEC 1993

Which of the following compounds of tin is a strong reducing agent?

A. SnCI₂
B. SnCI₄
C. SnO₂
D. SnH₄
E. Sn(OH)₂