Stoichiometry - Jamb Chemistry Past Questions and Answers

Question 6:

• JAMB 1978

Which of the five atoms can be described by the following properties: Relative atomic mass is greater than 30 but less than 40, it has odd atomic number and forms a unipositive ion in solution?

A. T
B. W
C. X
D. Y
E. Z

Question 7:

• JAMB 1979

How many grams of HBr would exactly be required to react with 2 g of propyne? (C =12, H=1, Br = 80)

A. 4. 1 g
B. 6. 1 g
C. 8. 1g
D. 16.2g

Question 8:

• JAMB 1979

The empirical formula of an oxide of nitrogen containing 30.4 per cent of nitrogen is (N=14.0,O=16.0)

A. N₂O₂
B. NO
C. NO₂
D. N₂O
E. N₂O₃

Question 9:

• JAMB 1979

Phosphorus burns in oxygen according to the equation P₄ + 50₂ → P₄O₁₀. How many litres of oxygen will be required at S.T.P for complete oxidation of 12.4g of phosphorus? [P = 31,O = 16 and molar volume of a gas at S.T.P = 22.4 litres]

A. 5. 20
B. 11. 20
C. 2. 24
D. 20. 20
E. 6. 20

Question 10:

• JAMB 1980

10cm³ of CO is mixed and sparked with 100cm³ of air containing 21% O₂. If all the volumes measured at S.T.P. the volume of resulting gases would be?

A. 90cm³
B. 100cm³
C. 105cm³
D. 110cm³
E. 115cm³