WAEC Past Questions and Answers - Page 1690

8,446.

An increase in the pressure of a gas results in a decrease in its

A.

mass

B.

vapour density

C.

volume

D.

temperature

E.

concentration

Correct answer is C

No explanation has been provided for this answer.

8,447.

If the atomic number of an element X is 11 and that of nitrogen is 7, the most likely formula of the nitride of X is

A.

X3N

B.

XN3

C.

X3N2

D.

N2X

E.

NX2

Correct answer is A

No explanation has been provided for this answer.

8,448.

A sodium atom and a sodium ion have the same

A.

number of neutrons

B.

number of electrons

C.

electric charge

D.

electronic structure

E.

chemical properties

Correct answer is A

No explanation has been provided for this answer.

8,449.

In linear molecules, the bond angle is

A.

90o

B.

140o

C.

109o

D.

120o

E.

180o

Correct answer is E

No explanation has been provided for this answer.

8,450.

What is the most probable group of an element which is a soft, silvery white solid and reacts violently with water?

A.

Group 0

B.

Group 1

C.

Group 4

D.

Group 6

E.

Group 7

Correct answer is B

No explanation has been provided for this answer.