Waec Chemistry Past Questions For Year 2008
Question 16
Which of the following gases has the lowerst rate of diffusion under the same conditions of temperature and pressure? [H = 1, O = 16, Ne = 20, CI = 35]
- A. Chlorine
- B. Hydrogen
- C. Neon
- D. Oxygen
Question 17
Consider the reaction represented by the following equation: Zn(s) + 2HCI(aq) → ZnCI2(aq) + H2(g) what volume of hydrogen gas is produced at s.t.p. when 3.25 g of zinc reacts with excess dilute HCI? [Zn = 65, Molar gas volume at s.t.p. = 22.4 dm-3]
- A. 1.12 dm3
- B. 2.24dm3
- C. 4.48dm3
- D. 8.96dm3
Question 18
If 5.00cm3 of 0.20 mol dm-3Na2CO3 was diluted with distilled water to obtain 250 cm3 solution, what is the concentration of the resulting solution?
- A. 0.004 mol dm-3
- B. 0.02 mol dm-3
- C. 0.20mol dm-3
- D. 0.40mol dm-3
Question 19
An aqueous solution of CaCI2 is
- A. acidic solution
- B. alkaline solution
- C. a buffer solution
- D. a neutral solution
Question 20
The colour of phenolphthalein indicator in dilute HNO
- A. colourless
- B. orange
- C. pink
- D. purple
