WAEC Chemistry Past Questions & Answers - Page 180

896.

Which of the following pairs of solutions will produce a precipitate when mixed?

A.

Pb(NO3)2(aq) and NaCI(aq)

B.

MgSO4(aq) and HCI(aq)

C.

ZnCI2(aq) and NaSO4(aq)

D.

NaOH(aq) and HNO3(aq)

Correct answer is A

\(Pb(NO_3)_{2(aq)} + 2NaCl → PbCl_2 + 2NaNO_3\) Option A will produce insoluble lead(II) chloride.( precipitate)

897.

Hardness in water can be removed by adding

A.

copper (ll) tetraoxosulphate (IV)

B.

sodium trioxocarbonate (IV)

C.

sodium chloride

D.

alum

Correct answer is B

No explanation has been provided for this answer.

898.

Ethyne undergoes the following reactions except

A.

polymerisation

B.

addition

C.

substitution

D.

esterification

Correct answer is D

No explanation has been provided for this answer.

899.

Fats are classified as

A.

hydrocarbons

B.

alkanoates

C.

alkanols

D.

carbohydrates

Correct answer is B

No explanation has been provided for this answer.

900.

The colour of the solution formed when ethyne reacts with an acidic solution of potassium tetraoxomanganate (VII) is

A.

purple

B.

colourless

C.

green

D.

pink

Correct answer is B

No explanation has been provided for this answer.