Waec Chemistry 1988 Past Questions and Answers

Question 31:

• WAEC 1988

Aqueous sodium trioxocarbonate (IV) solution is alkaline because

A. Acid from which it is formed is strong
B. Sodium is an alkali metal
C. Sodium trioxocarbonate (IV) is decomposed by water
D. Sodium trioxocarbonate (lV) is stable to heat
E. Sodium triocarbonate (IV) is hydrolysed in water

Question 32:

• WAEC 1988

Which of the following correctly explains why iodine crystals change directly into the gaseous state when heated?

A. Lodine crystals sublime
B. Lodine atoms are held together by strong forces
C. Lodine molecules are held together by weak forces
D. Lodine molecules are covalent
E. Lodine is a solid at room temperature

Question 33:

• WAEC 1988

Which of the following is a waste product in the Solvary Process for the manufacture of sodium trioxocarbonate (IV)?

A. Ammonium chloride
B. Brine
C. Limestone
D. Calcium oxide
E. Calcium chloride

Question 34:

• WAEC 1988

When copper (ll) chloride solution is treated with excess aqueous ammonia, a deep blue solution results This is due to the presence of

A. (CuNH₄)³⁺ ions
B. (CuCI₄)^2-ions
C. [Cu(OH)₄]^2- ions
D. Cu(H^2-O)₄²⁺ IONS
E. [cU(NH₃)₄] ^ions

Question 35:

• WAEC 1988

The complex salt formed when aluminium dissolves in sodium hydroxide solution is

A. Na₃AI(OH)₄
B. Na₂AI(OH)3
C. NaAI(OH)₃
D. Na₄AI(OH)₄
E. NaAI(OH)₄