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WAEC Chemistry Past Questions & Answers - Page 171

851.

How many orbitals are in the d-sub shell?

A.

1

B.

3

C.

5

D.

7

Correct answer is C

No explanation has been provided for this answer.

852.

In which of the following processes is biotechnology not applied?

A.

Manufacture of drugs

B.

Treatment of domestic sewage

C.

Production of alcoholic beverages

D.

Electroplating of metals

Correct answer is D

No explanation has been provided for this answer.

853.

Which of the following substance is an alloy of lead?

A.

Brass

B.

Duralumin

C.

Stainless steel

D.

Soft solder

Correct answer is D

No explanation has been provided for this answer.

854.

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(NO3)2(aq)+2NaClPbCl2+2NaNO3 Option A will produce insoluble lead(II) chloride.( precipitate)

855.

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.