Chemical combination - Jamb Chemistry Past Questions and Answers

Question 76:

• JAMB 1997

35 cm3 of hydrogen was sparked with 12 cm3 of oxygen at 110°C and 760mm Hg to produce steam. What percentage of the total volume of gas left after the reaction is hydrogen?

A. 11%
B. 31%
C. 35%
D. 69%

Question 77:

• JAMB 1997

35 cm3 of hydrogen was sparked with 12 cm3 of oxygen at 110°C and 760mm Hg to produce steam. What percentage of the total volume of gas left after the reaction is hydrogen?

A. 11%
B. 31%
C. 35%
D. 69%

Question 78:

• JAMB 1997

2.85g of an oxide of copper gave 2.52g of copper on reduction and 1.90g of another oxide gave 1.52g of copper on reduction. The data above illustrates the law of?

A. Constant composition
B. Conservation of mass
C. Reciprocal proportions
D. Multiple proportions

Question 79:

• JAMB 1997

An element, X, forms a volatile hydride XH₃ with a vapour density of 17.0. The relative atomic mass of X is?
(H = 1)

A. 34.0
B. 31.0
C. 20.0
D. 14.0

Question 80:

• JAMB 1997

A sample of a substance containing only C and H burns in excess O₂ to yield 4.4g of CO₂
and 2.7 g of H₂O. The empirical formula of a substance is?
(C = 12, O = 16, H = 1)

A. CH₃
B. CH₂
C. CH₄
D. C₂H₂₄