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.

2,786.

When a solution of silver (l) nitrate is saturated with hydrogen sulphide, a black precipitate forms which is?

A.

H2S

B.

Ag2S

C.

PbS

D.

HNO3

E.

S

Correct answer is B

No explanation has been provided for this answer.

2,787.

1.00 g of the oxide of metal X (atomic mass = 64) gave 0.80 g of the metal when reduced with hydrogen.
The formula of the oxide is?

A.

X2O

B.

XO

C.

XO2

D.

X2O3

E.

X3O4

Correct answer is B

No explanation has been provided for this answer.

2,788.

In the chemical reaction A + B \(\to\) C + D, more of D is formed?

A.

if the concentrated of A is reduced

B.

if the concentrated of B is reduced

C.

if the concentrated of C is reduced

D.

if the concentration of C is increased

E.

if D is continuously removed from the reaction mixture

Correct answer is E

No explanation has been provided for this answer.

2,789.

In the reaction N2(g) + O(g)
↔ 2NO(g) produced i an increase in the total pressure will?

A.

cause less nitrogen to be produced in the equilibrium mixture

B.

cause less nitric oxide to be produced in the equilibrium mixture

C.

cause more nitric oxide to be produced in the equilibrium mixture

D.

cause more oxygen to be produced in the equilibrium mixture

E.

have no effect

Correct answer is E

If the pressure is increased, the position of equilibrium. moves in the direction of the fewest moles. of gas

However, because there is an equal number of particles on both sides, change in pressure will have no effect on the system.

2,790.

Which of the following CANNOT be obtained by fractional distillation of petroleum?

A.

Ether

B.

Methane

C.

Butane

D.

Ethene

E.

Hydrogen

Correct answer is E

The fractional distillation of crude oil gives several products in liquid and gaseous forms. The products that are in the gaseous form include petroleum gas or LPG (liquefied petroleum gas) e.g. methane, ethane, propane, butane, propylene, butylene, propane, etc.

Therefore the answer to this question is hydrogen.