Waec Chemistry Past Questions For Year 1991
Question 1
The separation of a mixture of calcium trioxocarbonate (lV) and sodium trioxocarbonate (IV) is most easily carried out by using the differences in their
- A. physical states
- B. melting points
- C. Rf. values
- D. solubility
- E. boiling points
Question 2
In which of the following is the oxidation number of nitrogen zero?
- A. SO2 and NH3
- B. NaNO3
- C. HNO2
- D. NOI3
- E. N2
Question 3
The metal extracted from cassiterite is
- A. calcium
- B. copper
- C. tin
- D. sodium
- E. lead
Question 4
CH2 = CH2 + H2SO4 → CH3 - CH2 -OSO3H. The reaction illustrated by the equation above is an example of
- A. substitution
- B. oxidation
- C. reduction
- D. addition
- E. displacement
Question 5
Which of the following elements can from more than one acidic oxide?
- A. Hydrogen
- B. Sulphur
- C. Carbon
- D. Alumium
- E. Iron
