WAEC Chemistry Past Questions & Answers - Page 255

1,271.

When naphthalene on heating changes from the solid state directly to the gaseous state it undergoes

A.

evaporation

B.

sublimation

C.

decomposition

D.

combustion

E.

ionisation

Correct answer is B

No explanation has been provided for this answer.

1,272.

Calcium is usually extracted by the electrolysis of its

A.

trioxonitrate (V)

B.

tetraoxosulphate (IV)

C.

oxide

D.

hydride

E.

chloride

Correct answer is E

No explanation has been provided for this answer.

1,273.

Polyatomicity is illustrated by molecules of

A.

sulphur

B.

carbon (IV) oxide

C.

noble gases

D.

liquefied oxygen

E.

liquefied nitrogen

Correct answer is A

No explanation has been provided for this answer.

1,274.

The following will decolourize acidified potassium tetraoxomanganate (VII) solution except

A.

sulphur (lV) oxide

B.

but-3-ene

C.

pentane

D.

hydrogen sulphide

E.

propyne

Correct answer is C

No explanation has been provided for this answer.

1,275.

Tetraoxosulphate (lV) acid is described as strong acid because it is highly

A.

corrosive

B.

concentrated

C.

reactive

D.

soluble in water

E.

ionized in water

Correct answer is E

No explanation has been provided for this answer.