Stoichiometry - Jamb Chemistry Past Questions and Answers

Question 46:

• JAMB 1990

0.1 faraday of electricity deposited 2.95 g of nickel during electrolysis of an aqueous solution.
Calculate the number of moles of nickel that will be deposited by 0.4 faraday?
(Ni = 58.7)

A. 0.20
B. 0.30
C. 0.04
D. 5.87

Question 47:

• JAMB 1991

An iron ore is known to contain 70.0% Fe₂O₃. The obtain from 80kg of the ore is?
(Fe = 56, O = 16)

A. 35.0 kg
B. 39.2 kg
C. 70.0 kg
D. 78.4 kg

Question 48:

• JAMB 1991

Calculate the volume of carbon (IV)oxide measured at s.t.p, produced when 1 kg of potassium hydrogen trioxocarbonate (IV) is totally decomposed by heat?
(G.M.V. at s.t.p 22.4 dm³, K = 39, O = 16, C = 12, H = 1)

A. 28 dm³
B. 56 dm³
C. 112 dm³
D. 196 dm³

Question 49:

• JAMB 1991

A given quantity of a gas occupies a volume of 228 cm³ at a pressure of 750mm Hg. What will be its volume at atmospheric pressure?

A. 220 cm³
B. 225 cm³
C. 230 cm³
D. 235 cm³

Question 50:

• JAMB 1991

A sample of a gas exerts a pressure of 8.2 atm when confined in a 2.93 dm³ container at 20°C. The number of moles of gas in the sample is?
(R = 0.082 litre atm / deg mole)

A. 1.00
B. 2.00
C. 3.00
D. 4.00