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.

1,381.

What is the value of n in the following equation? Cr2O72- + 14H+ + ne- → 2Cr 3+ + 7H2O

A.

2

B.

3

C.

6

D.

7

Correct answer is C

No explanation has been provided for this answer.

1,382.

Consider the following reaction equation: X(g)
+ Y(g) ⇌ XY(g); ∆H = + 220KJ mol-1 If the temperature of the system is increased, the

A.

backward reaction would be favoured

B.

forward reaction would favoured

C.

reaction would stop

D.

reaction would be at equilibrium

Correct answer is B

No explanation has been provided for this answer.

1,383.

On evaporation to dryness, 250 cm3 of saturated solution of salt X with relative molar mass 101 gave 50.5g of the. What is the soluility of the salt?

A.

1.0 mol dm-3

B.

2.0 mol dm-3

C.

4.0 moldm-3

D.

5.0 moldm-3

Correct answer is B

50.5g 0f salt X is contained in 250cm3,

what mass of X is contained in 1000cm3 

= (50.5 x 1000) ÷ 250 = 202g

no of moles of salt x = mass÷ molar mass

= 202÷ 101 = 2.0mol/dm3

1,384.

Which of the following metallic oxides is amphoteric?

A.

AI2O3

B.

Fe2O3

C.

MgO

D.

Na2O

Correct answer is A

No explanation has been provided for this answer.

1,385.

When NH 4CI was dissolved in water, the container was cold to touch. This implies that

A.

the process is endothermic

B.

the process is exothermic

C.

NH4CI is highly soluble in water

D.

NH 4CI forms a saturated solution

Correct answer is A

No explanation has been provided for this answer.