Jamb Chemistry 2014 Past Questions and Answers

Question 26:

• JAMB 2014

If the change in free energy of a system is -899 Jmol^-1 and the entropy change is 10Jmol^-1k^-1 at 250C, calculate the enthalpy change.

A. +2081 Jmol^-1
B. -2081 Jmol^-1
C. -649 Jmol^-1
D. +649 Jmol^-1

Question 27:

• JAMB 2014

In an equilibrium reaction, which of the following conditions indicates that maximum yield of the product will be obtained?

A. Equilibrium constant is very large
B. ∆H - T∆S = O
C. ∆ H > T ∆ S
D. Equilibrium constant is less than zero

Question 28:

• JAMB 2014

In a chemical reaction, the change in concentration of a reactant with time is

A. Entropy of reaction
B. Enthalpy of reaction
C. Rate of reaction
D. Order of reaction

Question 29:

• JAMB 2014

Cr ₂O\(\frac{2 -}{7}\) (aq) + H ₂O(1)⇌ 2CrO \(\frac{2 -}{4}\) (aq) + 2H ⁺ (aq)
What happens to the reaction above when the hydrogen ion concentration is increased?

A. More of the products will be formed
B. The reaction will not proceed
C. The equilibrium position will shift to the right
D. The equilibrium position will shift to the left.

Question 30:

• JAMB 2014

Which of the following will shift to the left from dilute tetraoxosulphate (VI) acid?

A. Lead
B. Magnesium
C. Cpper
D. Gold