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.

3,266.

In the electrolytic extraction of aluminum, the function of the molten cryolite is to

A.

precipitate aluminium hdroxide

B.

lower the melting point of aluminium oxide

C.

act as a raw materials

D.

act as a solvent

Correct answer is B

No explanation has been provided for this answer.

3,267.

The type of iron that is best suited for welding, making nails, chains and iron rods is?

A.

pig iron

B.

wrought iron

C.

cast iron

D.

iron pyrites

Correct answer is B

uses of wrought iron

  • It is used to make decor items like table base, candle holder, curtain rods etc.
  • It is used in making pipes.
  • It is used in making fences and gates.
  • It is used in making nuts, bolts, rivets etc.
  • It is used in making chains.

3,268.

Copper metal dissolves in concentrated trioxonitrate (V) acid with the resultant evolution of?

A.

CO2

B.

SO2

C.

NO2

D.

CO

Correct answer is C

Oxidation of Copper turnings with concentrated trioxonitrate (V) acid wil

 Cu + 4HNO\(_3\) → CuNO\(_3\) + 2H\(_2\)O +2NO\(_2\).

3,269.

which of the following metals will show the highest metallic character?

A.

Zinc

B.

Copper

C.

Barium

D.

Calcium

Correct answer is C

The reactivity series of metals, also known as the activity series, refers to the arrangement of metals in the descending order of their reactivities.

Na > Ca > Mg > Al > Zn > Fe > Sn > Pb > Cu > Ag.

Considering metallic property which increases down the group, barium will be ranked calcium 

3,270.

Which of the following allotrope of carbon is a constituent of a lead pencil?

A.

Graphite

B.

Diamond

C.

Lampblack

D.

Soot

Correct answer is A

When an element exists in more than one crystalline form, those forms are called allotropes; the two most common allotropes of carbon are diamond and graphite.

Graphite is used in pencils and lubricants. It is a good conductor of heat and electricity. Its high conductivity makes it useful in electronic products such as electrodes, batteries, and solar panels.