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.

2,116.

The earthly impurities in iron ore are removed in the blast furnace by the reaction

A.

CO2 + C →2CO

B.

Fe2O3 + 3CO →2Fe + 3CO2

C.

SiO2 + CaO →CaSiO3

D.

CaCO3 → CaO + CO2

E.

C +CO2 → CO2

Correct answer is C

No explanation has been provided for this answer.

2,117.
2,118.

Which of the following statements best explains cracking ? It is a process

A.

in which an alkene adds on itself repeatedly to form long chain polymers

B.

in which large hydrocarbon molecules are broken into smaller units

C.

for measuring theoctane number of petrol

D.

in which carbon chain results in a zigzag arrangement

E.

in which aromatic hydrocarbons are produced

Correct answer is B

No explanation has been provided for this answer.

2,119.

Which of the following reactions represents the laboratory preparation of hydrogen?

A.

C(s) + H 2 O(l) → CO(g) + H2(g)

B.

2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g)

C.

Zn(s) + 2HCI(aq) → ZnCI2(aq) + H2(g)

D.

Cu(s) + H2O(l) → CuO(s) + H2(g)

E.

2AI(s) + 3H2O(l) → Al2O3(s) + 3H2(g)

Correct answer is C

No explanation has been provided for this answer.

2,120.

The major raw material in a plastic industry is

A.

ethanol

B.

sulphur

C.

methylethanoate

D.

ethene

E.

ethane

Correct answer is D

- Earlier, molasses act as a raw material which yield ethanol from which ETHENE (gotten is used to) produce a range of poly(ethene) plastics.

- Nowadays, starting new raw materials are obtained by the fractional distillation of crude oil or petroleum.

- During the thermal cracking of petroleum; long chain alkanes are converted into smaller chain alkanes, ALKENES (with Ethene being the predominate), etc.

- The Alkenes such as Ethene and Propene can be made into Poly(ethene) / plastic, nylon, etc.