Waec Chemistry 2007 Past Questions and Answers

Question 36:

• WAEC 2007

Which of the following methods can be used to separate a mixture of two miscible liquids with different boiling points?

A. Decantation
B. Distillation
C. Evaporation
D. Filtration

Question 37:

• WAEC 2007

The following substances are heavy chemicals except

A. Sodium trioxocarbonate (IV)
B. Tetraoxosulphate (VI) acid
C. Lead (lV) tetraethyl
D. Sodium hydroxide

Question 38:

• WAEC 2007

Pig-iron is brittle because it contains

A. A high percentage of carbon as impurity
B. Calcium trioxosilicate (IV)
C. Unreacted haematite
D. Undecomposed limestone

Question 39:

• WAEC 2007

What volume will 0.5 g of H₂ occupy at s.t.p? [H = 1; 1 mole of a gas occupy 22.4 dm³ at s.t.p.]

A. 2.24 dm³
B. 5.60dm³
C. 11.20dm³
D. 44.80dm³

Question 40:

• WAEC 2007

Which of the these metals will not liberate hydrogen from dilute HCI?

A. Copper
B. Iron
C. Magnesium
D. Zinc