Waec Chemistry Past Questions
Question 31
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 32
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
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 34
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 35
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)
