Stoichiometry - Jamb Chemistry Past Questions and Answers

Question 1:

• JAMB 2019

56.00cm³ of a gas at S.T.P. weighed 0.11g. What is the vapour density of the gas?
[Molar volume of a gas at S.T.P = 22.4dm³

A. 11.00
B. 22.00
C. 33.00
D. 44.00
E. 55.00

Question 2:

• JAMB 2019

Which is the temperature of a given mass of a gas initially at and 9 atm, if the pressure is reduced to 3 atm at constant volume?

A. 91K
B. 182K
C. 273K
D. 819K
E. 429K

Question 3:

• JAMB 2019

Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
From the equation above, the mass of magnesium required to react with 250cm³ of 0.5M HCl is [Mg = 24]

A. 0.3g
B. 1.5g
C. 2.4g
D. 3.0g

Question 4:

• JAMB 2019

A gaseous metallic chloride MCl_x consists of 20.22% of M by mass. The formula of the chloride is [M = 27, Cl = 35.5]

A. MCl
B. MCL₂
C. MCL₃
D. M₂Cl₆

Question 5:

• JAMB 1978

An element X forms the following compounds with chlorine; XCl₄, XCl₃, XCl₂. This illustrates the

A. Law of multiple proportions
B. Law of chemical proportions
C. Law of simple proportions
D. Law of conservation of mass
E. Law of definite proportions