NECO Chemistry Past Questions & Answers - Page 10

46.

In which of these groups will all the substances be insoluble in water?

A.

Na2CO3, KNO3,(NH4)2C03

B.

NaHCO3, PbSO4, CaSO4

C.

K2C03, CaSO4, AgNO3

D.

PbCl2, NaCl, ZnCl2

E.

ZnCO3, BaSO4,AgCl

Correct answer is E

No explanation has been provided for this answer.

47.

What is the maximum number of electrons that an f-orbital can accommodate?

A.

2

B.

6

C.

7

D.

10

E.

14

Correct answer is E

No explanation has been provided for this answer.

48.

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.

49.

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.

50.

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.