Waec Chemistry 1994 Past Questions and Answers

Question 6:

• WAEC 1994

In any chemical reaction, the total mass of the products is always equal to that of the reactants. This is statement of the law of

A. Definite proportion
B. Conservation of matter
C. Multiple proportions
D. Reciprocal proportions
E. Constant composition

Question 7:

• WAEC 1994

Which of the following is not a property of magnesium oxide?

A. High melting point
B. Dissolution in polar solvents
C. Presence of ionic bonds
D. Possession of crystal lattice
E. Low binding energy

Question 8:

• WAEC 1994

Which of the following would increase the rate of reaction of chips of a metal M as shown in the equation below? M_(s) + 2HCI_(aq) → MCI_2(aq) + H_2(g)

A. Diluting the hydrochloric acid
B. Adding some distilled water
C. Decreasing the temperature
D. Grinding the metal into powder
E. Increasing the pressure

Question 9:

• WAEC 1994

The oxidation number of phosphorus in PO 3/4 is

A. + 1
B. +2
C. +3
D. +4
E. +5

Question 10:

• WAEC 1994

The number of atoms in 1.2g of carbon - 12 isotope is

A. 1.00 x 10 ₂₂
B. 6.02 x 10₂₂
C. 1.20 x 10 ₂₃
D. 1.00 x 10₂₃
E. 6.02 x 10₂₄