Waec Chemistry 1993 Past Questions and Answers

Question 16:

• WAEC 1993

Consider the reaction represented by the following equation CaCI_2(aq) + H ₂C₂O _4(aq) ⇌ CaC ₂O_4(s) + 2HCI_(aq). Which of the following would dissolve the precipitate of CaC ₂O₄ formed?

A. Stirring the mixture vigorously
B. Adding more calcium chloride solution
C. Lncreasing the concentration of the ethanedioic acid
D. Adding concentrated hydrochloric acid
E. Adding some distilled water

Question 17:

• WAEC 1993

The following gases decolorize bromine water except

A. C₂H₆
B. C₂H₄
C. C₂H₂
D. C₃H₄
E. C₃H₆

Question 18:

• WAEC 1993

What volume of distilled water should be added to 400cm3 of 2.0 mole dm-3 \(H_{2}SO_{4}\) to obtain 0.20 mole dm-3 of solution>

A. 600cm-³
B. 800cm-³
C. 1,000cm-³
D. 3,600cm-³
E. 4,000cm-³

Question 19:

• WAEC 1993

Which of the following indicates the correct increasing order of oxidizing power of the halogens?

A. F < CI < Br < l
B. L < Br < CI < F
C. I < CI < Br < F
D. Br < I < CI < F
E. CI < F < I < Br

Question 20:

• WAEC 1993

Which of the following substances is a peroxide?

A. Na₂O₂
B. CuO
C. PbO₄[/sub]
D. Fe₂O[/sub]
E. AI₂O[/sub]