Waec Chemistry Past Questions For Year 2007

Question 11

14.8 g of a salt (z)dissolved in 250 cm³ of distilled water gives a concentration of 0.80 mol dm^-3. Calculate the molar mass of the salt (z).

waec 2007

• A. 13.5 g mol^-1
• B. 18.5 g mol^-1
• C. 47.4 g mol^-1
• D. 74.0 g mol^-1

Question 12

Which of the following species does not contain a co-ordinate bond?

waec 2007

• A. AI₂CI₆
• B. CCI₄
• C. H₃O⁺
• D. NH ⁺ ₄

Question 13

Which of the following compounds has hydrogen bonds between its molecules?

waec 2007

• A. HF
• B. HBr
• C. HCI
• D. HI.

Question 14

Consider the reaction represented by the equation: Ca(OH)_2(aq) + CO _2(g) → CaCO3_(s) + H ₂O_(l)

in the reaction above, CO ₂ acts as

waec 2007

• A. an acidic oxide
• B. an oxidizing agent
• C. a basic oxide
• D. a dehydrating agent

Question 15

In which of the following compound (s) will heat be absorbed on adding water?

l. KNO\(_3\) II. Concentrated H\(_2\)SO\(_4\) III. NH\(_4\)CI

waec 2007

• A. I only
• B. lll only
• C. l and lll only
• D. ll and lll only