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.

1,646.

CuSO4 5H2O can be obtained from an aqueous solution of copper (ll) tetraoxosulphate (VI) by

A.

evaporation to dryness

B.

using chromatography

C.

precipitation

D.

crystallization

Correct answer is D

No explanation has been provided for this answer.

1,647.

Equal amounts of marble chips are reacted separately with 100cm3 of hydrochloric acid of different concentrations . if all the marble chips reacted, which of the following remained the same in each case?

A.

Average rate of evolution of gas

B.

Total mass of gas evolved during the reaction

C.

Time taken for the reaction to reach completion

D.

lnitial reaction rates

Correct answer is B

No explanation has been provided for this answer.

1,648.

What will happen if more heat is applied to the following system at equilibrium? X2(g) + 3Y 2(g) ⇌ 2XY3(g); ∆H =-kJmol -1

A.

the yield of XY 3 will decompose

B.

more of XY3 will decompose

C.

More of X2 will react

D.

the forward reaction will go to completion

Correct answer is B

No explanation has been provided for this answer.

1,649.

Which of the following salt solutions will have a pH greater than 7?

A.

NaCl(aq)

B.

Na2CO3(aq)

C.

Na2SO4(aq)

D.

NaHSO4(aq)

Correct answer is B

No explanation has been provided for this answer.

1,650.

Calculate the mass of sodium hydroxide in 5.00 dm3 of a 0.125 mol dm-3 solution [NaOH = 40 g mol]

A.

0.0156 g

B.

0.625 g

C.

1.00 g

D.

25.0 g

Correct answer is D

1 mole of NaOH per dm3 has a mass of 40g mass of NaOH in 0.125 mole = 0.125 x 40 = 5g mass in 5.00 dm3 of the solution = 5 x 5 = 25.0g