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.

3,276.

CuO(s) + H\(_2\)(g) ↔ Cu(s) + H\(_2\)O(g)
What is the effect of increasing the pressure on the equilibrium reaction above?

A.

The equilibrium is shifted to the left

B.

The equilibrium is shifted to the right

C.

There is no effect

D.

More H2(g) is produced

Correct answer is C

When amount / volume of gaseous reactants equal amount / volume of gaseous products, the change in pressure has no effect on the equilibrium position.

3,277.

A catalyst increase the rate of a chemical reaction by providing a path that?

A.

raise the activiation energy

B.

increase the temperature

C.

lowers the activation energy

D.

increase the concentration

Correct answer is C

The rate of a reaction can be increased by adding a suitable catalyst.

A catalyst is a substance which increases the rate of a chemical reaction but it is not used up (remains chemically unchanged at the end).

It provides an alternative reaction pathway of lower activation energy.

3,279.

Two equal bulbs, one containing ammonia and the other nitrogen are opened mouth - to - mouth to each other at room temperature. The entropy in the mixture of gases is likely to?

A.

remain unchange

B.

increase

C.

decrease

D.

change

Correct answer is B

When two or more gases are mixed together at constant volume, there is an increase in entropy.

3,280.

C(s) + H2O(g) → H2(g) + CO2(g)
ΔG for the reaction above at 1300k is -43KJ. At this temperature, the reaction is?

A.

not feasible

B.

at equilibrium

C.

feasible

D.

exothermic

Correct answer is C

For a reaction to be feasible, ΔG has to be negative.