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.

2,651.

Aluminium is extracted commercially from its ore by?

A.

heating aluminium oxide with coke in a furance

B.

the electrolysis of fused aluminium oxide in cryolite

C.

treating cryolite with sodium hydroxide solution under prressure

D.

heating sodium aluminium silicate to a high temperature

Correct answer is B

No explanation has been provided for this answer.

2,652.

Chlorine is produced commmercially by?

A.

electrolysis of dilute hydrochloric acid

B.

electrolysis of brine

C.

neutralization of hydrogen chloride

D.

heating potassium trioxochlorate (V)

Correct answer is B

No explanation has been provided for this answer.

2,653.

The thermal decomposition of copper (ll)trioxonitrate (V) yields copper (ll) oxide, oxygen and?

A.

nitrogen (ll) oxide

B.

nitrogen (l) oxide

C.

nitrogen (lV) oxide

D.

nitrogen

Correct answer is C

No explanation has been provided for this answer.

2,654.

Suitable reagents for the laboratory preparation nitrogen are?

A.

sodium dioxonitrate (III) and ammonium chloride

B.

sodium dioxonitrate (V) and ammonium chloride

C.

sodium chloride and ammonium chloride

D.

sodium chloride and ammonium diozonitrate (III)

Correct answer is A

No explanation has been provided for this answer.

2,655.

When H2S gas is passed into a solution of iron (III) chloride, the colour changes from yellow to green. This is because?

A.

H(s)S is reduced to S

B.

Fe3+ ions are oxidized by H(s)S

C.

Fe3+ ions are oxidized Fe3+ ions

D.

Fe3+ ions are reduced to Fe2+ ions

Correct answer is D

No explanation has been provided for this answer.