Jamb Chemistry 2007 Past Questions and Answers

Question 21:

• JAMB 2007

Dissolving some pellets of NaOH in water would result in

A. A decrease in the free energy of the solution
B. A decrease in the entropy of the solution
C. A lowering of the temperature of te solution
D. An increase in the entropy of the solution

Question 22:

• JAMB 2007

Calculate the number of moles of HCl present in 20cm³ of a 0.75M solution of the acid

A. 0.015 mole
B. 0.038 mole
C. 3.800 moles
D. 1.500 moles

Question 23:

• JAMB 2007

The oxidation state of oxygen in tetraoxosulphate (VI) acid is

A. -4
B. -2
C. +4
D. -8

Question 24:

• JAMB 2007

MnO_2(s) + xHCl_(aq) → MnCl_2(aq) + yH₂O_(l) + zCl_2(g)
In theequation above, what are the values of x, y and z respectively

A. 2, 1, 2
B. 4, 1, 2
C. 4, 2, 1
D. 1, 2, 1

Question 25:

• JAMB 2007

Calculate the mass of chlorine gas which occupies a volume of 1.12dm³ at s.t.p
[Cl = 35.5, molar volume of gas at s.t.p = 22.4 dm³

A. 15.50 g
B. 7.10 g
C. 3.55 g
D. 1.80 g