NECO Chemistry Past Questions & Answers - Page 7

31.

Which of these compounds has the greatest ionic character?

A.

AlF3

B.

BF2

C.

CF4

D.

CsF

E.

NaF

Correct answer is E

Sodium fluoride because, of all the metals listed, sodium is the most reactive while fluorine is the most reactive non-metal,  distance between sodium and fluorine in the periodic table also is a factor

32.

What kind of bond exist between carbon and oxygen in C03 2-?

A.

Co- ordinate Covalent

B.

covalent

C.

Electrovalent

D.

Metallic

E.

Van der Waal forces

Correct answer is B

No explanation has been provided for this answer.

33.

Which of the following gases will bleach moist litmus paper?

A.

Cl2

B.

CO2

C.

HCl

D.

N2O

E.

SO3

Correct answer is A

No explanation has been provided for this answer.

34.

Which of the following compounds will undergo thermal dissociation?

A.

AgCl

B.

CaCO3

C.

K2S04

D.

NaOH

E.

NH4CI

Correct answer is E

No explanation has been provided for this answer.

35.

The rate of a reaction usually increases with increase in the concentration of reactants because the

A.

distance between particles of the reactants increases

B.

frequency of collision of particles is lower

C.

particles of the reactants gain energy and move faster

D.

reactants from a complex which decomposes rapidly

E.

reactants occupy a higher energy level

Correct answer is D

No explanation has been provided for this answer.