JAMB Chemistry Past Questions & Answers - Page 221

1,101.

When H2S gas is passed into a solution of iron (III) chloride, the colour changes from yellow to green. This is because?

A.

H(s)S is reduced to S

B.

Fe3+ ions are oxidized by H(s)S

C.

Fe3+ ions are oxidized Fe3+ ions

D.

Fe3+ ions are reduced to Fe2+ ions

Correct answer is D

No explanation has been provided for this answer.

1,102.

Which of the following is used in fire extinguishers?

A.

Carbon (ll) oxide

B.

Carbon (lV) oxide

C.

Sulphur (lV) oxide

D.

Ammonia

Correct answer is B

No explanation has been provided for this answer.

1,103.

Which property of a reversible reaction is affected by a catalyst?

A.

Heat content (enthalphy)

B.

Energy of activation

C.

Free energy change

D.

Equilibrium position

Correct answer is B

No explanation has been provided for this answer.

1,104.

Which of the followingstatements is TRUE?

A.

The dissolution of NaOH(s) in water is endothermic

B.

The heat os solution of NaOH(s) is positive

C.

The NaOH(s) gains heat from the surroundings

D.

The heat of solution of NaOH(s) is negative

Correct answer is D

No explanation has been provided for this answer.

1,105.

Which of the following will produce the greatest increase in the rate of the chemical reaction represented by the equation Na2S2O3(aq) + 2HCl(aq) → 2NaCI(aq) + H2O(I) + SO2(g) + S(g)?

A.

A decrease in temperature and an increase in the concentration of the reactants

B.

An increase in the temperature and a decrease in the cocentration of the reactants

C.

An increase in temperature and an increase in the concentration of the reactants

D.

A decrease in the temperature and a decrease in the concentration of the reactants

Correct answer is C

No explanation has been provided for this answer.