NECO Chemistry Past Questions & Answers - Page 11

51.

A measure of the degree of disorderliness in a chemical system is known as the

A.

activation energy

B.

enthalpy

C.

entropy

D.

equilibrium

E.

free energy.

Correct answer is C

No explanation has been provided for this answer.

52.

A substance is said to be hygroscopic when it

A.

absorbs atmospheric moisture and then goes into solution

B.

absorbs atmospheric moisture but does not go into solution

C.

changes colour

D.

is not affected by atmospheric moisture

E.

losses its water of crystallization

Correct answer is B

No explanation has been provided for this answer.

53.

The electrode potential in volts of 2H+(aq) / H2(q) system is

A.

-2.87

B.

-2.71

C.

0.8

D.

1.68

Correct answer is E

No explanation has been provided for this answer.

54.

Chromatography is used to separate components of mixtures which differ in their rates of

A.

diffusion

B.

migration

C.

reaction

D.

sedimentation

E.

sublimation

Correct answer is B

No explanation has been provided for this answer.

55.

During the electrolysis of sodium Chloride solution, hydrogen is discharged at the carbon cathode because

A.

hydrogen ions are in greater concentration than sodium ions.

B.

hydrogen is higher than sodium in the electrochemical series.

C.

hydrogen is lower than sodium in the electrochemical series.

D.

of the nature of the electrodes.

E.

the concentration of sodium ions is greater than that of the hydrogen ion in the electrolyte.

Correct answer is C

No explanation has been provided for this answer.