Chemistry questions and answers

Chemistry Questions and Answers

Learn more about the properties, composition, and structure of substances (elements and compounds) with these Chemistry questions and answers. This Test can be used by students preparing for Chemistry in JAMB, WAEC, NECO or Post UTME.

3,616.

When dissolved in water, NaOH flakes show

A.

An endothermic change

B.

An exothermic change

C.

A slow reaction

D.

A rapid reaction

Correct answer is B

No explanation has been provided for this answer.

3,617.

The Arrhenius equation expresses the relationship between the speed of a reaction and its

A.

Molecular collision

B.

Heat of reaction

C.

Catalyst

D.

Activation energy

Correct answer is D

No explanation has been provided for this answer.

3,618.

When H2S is passed into a solution of iron (III) chloride, the solution turns

A.

Pale green

B.

Pale red

C.

Brown

D.

Colourless

Correct answer is A

A reaction between Iron (iii) chloride and Hydrogen sulphide leads to the reaction

2FeCl3(aq) + H2S(g) → 2FeCl2(aq) + 2HCl(aq) + S(s)

The colour change is from REDDISH BROWN to PALE GREEN.

3,619.

PCl5(g) ↔ PCl3(g) + Cl2(g)
In the reaction above, a decrease in pressure will

A.

Decelerate the reaction

B.

Increase the yield of PCl3

C.

Increase the yield of PCl5

D.

Accelerate the reaction

Correct answer is B

No explanation has been provided for this answer.

3,620.

Which of the following equations show that a reaction is in equilibrium?

A.

ΔG < O

B.

ΔG = ΔH – TΔS

C.

ΔG > O

D.

ΔG = O

Correct answer is D

No explanation has been provided for this answer.