WAEC Chemistry Past Questions & Answers - Page 196

976.

Which of the compounds will leave a metal residue when heated?

A.

Cu(NO 3 )2

B.

AgNO3

C.

K2CO3

D.

CaCO3

Correct answer is B

No explanation has been provided for this answer.

977.

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.

978.

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.

979.

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.

980.

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.