Stoichiometry - Jamb Chemistry Past Questions and Answers

Question 31:

• JAMB 1984

At S. T. P how many litres of hydrogen can be obtained from the reaction of 500 cm³ of 0.5 M H ₂SO ₄ with excess zinc metal?
(Gram molecular volume of H₂ = 22. 4 dm ³)

A. 22.4 dm ³
B. 11 . 2 dm ³
C. 6. 5 dm ³
D. 5. 6 dm ³
E. 0. 00 dm ³

Question 32:

• JAMB 1985

0.499g 0f CuSO₄.xH₂O when heated to constant weight gave a residue of 0.346g. the value of x is? (Cu = 63.5, S = 32.0, O = 16, H = 1)

A. 0.5
B. 2.0
C. 3.0
D. 4.0
E. 5.0

Question 33:

• JAMB 1985

Given that the molecular mass of iron is 56 and that of oxygen is 16, how many moles of iron(iii)oxide will be contained in 1kg of the compound?

A. 25.0 moles
B. 12.5 moless
C. 6.25 moles
D. 3.125 moles
E. 0.625 moles

Question 34:

• JAMB 1986

The number of atoms of chlorine present in 5.85g of NaCl is [Avogaro's Number = 6.02 x 10²³]

A. 6.02 x 10²²
B. 5.85 x 10²³
C. 6.02 x 10²³
D. 5.85 x 10²⁴

Question 35:

• JAMB 1986

How much of magnesium is required to react with 260cm³ of 0.5 M HCl? [Mg = 24]

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