Waec Chemistry Past Questions For Year 1989
Question 1
Which of the following statements best explains cracking ? It is a process
- A. in which an alkene adds on itself repeatedly to form long chain polymers
- B. in which large hydrocarbon molecules are broken into smaller units
- C. for measuring theoctane number of petrol
- D. in which carbon chain results in a zigzag arrangement
- E. in which aromatic hydrocarbons are produced
Question 2
Which of the following reactions represents the laboratory preparation of hydrogen?
- A. C(s) + H 2 O(l) → CO(g) + H2(g)
- B. 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)
- C. Zn(s) + 2HCI(aq) → ZnCI2(aq) + H2(g)
- D. Cu(s) + H2O(l) → CuO(s) + H2(g)
- E. 2AI(s) + 3H2O(l) → Al2O3(s) + 3H2(g)
Question 3
The major raw material in a plastic industry is
- A. ethanol
- B. sulphur
- C. methylethanoate
- D. ethene
- E. ethane
Question 4
The following are miscible with water except
- A. ethylethanoate
- B. methanol
- C. ethanoic acid
- D. methanoic acid
- E. ethanol
Question 5
The most suitable method to use when separating an insoluble solid from a liquid is
- A. evaporation
- B. filtration
- C. magnetization
- D. sublimation
- E. distillation
