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.

3,566.

What mass of K2CrO4 is required to prepare 250cm3 of 0.020 mol dm3 solution?
[K2CrO4 = 194.2g mol-1]

A.

0.97g

B.

9.70g

C.

19.42g

D.

97.10g

Correct answer is A

1 mole m-3 K2CrO4 contains 194.2g mol-1 in 1000cm3
1 mole m-3 K2CrO4 contains 92.2g mol-1 in 500cm3
1 mole m-3 K2CrO4 contains 48.55g mol-1 in 250cm3
If n molm-3 K2CrO4 contain 48.55
0.02 molm-3 will contain (0.02/1) * (48.55/1) = 0.97g

3,567.

A liquid that will dissolve fat is?

A.

Hydrochloric acid

B.

Calcium hydroxide

C.

Kerosene

D.

Water

Correct answer is C

No explanation has been provided for this answer.

3,568.

The structural component that makes detergent dissolve more quickly in water than soap is

A.

-SO3- Na+

B.

-COO-Na-

C.

-SO4- Na+

D.

-COO-K+

Correct answer is A

No explanation has been provided for this answer.

3,569.

Which of the following ions is acidic?

A.

K+

B.

KNO3-

C.

S2-

D.

H3O+

Correct answer is D

Acids are substances which produces hydrogen ions (or protons) as the only positive ion when dissolved in water.

\(H_{3}O^{+} \to 2H^{+} + OH^{-}\)

3,570.

A consequence of global warming is?

A.

air pollution

B.

water pollution

C.

increased humudity

D.

flooding

Correct answer is D

No explanation has been provided for this answer.