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.

206.

An organic functional group which can likely decolorize ammoniacal silver nitrate is?

A.

alkene

B.

alkane

C.

alkyne

D.

alkanol

Correct answer is C

Terminal alkynes react with Tollens reagent (ammoniacal silver nitrate solution) to form silver alkynides as a white precipitate, whereas internal alkynes do not react with Tollens reagent.

207.

Zn + 2HCL → ZnCl\(_2\) + H\(_2\) 

What happens to zinc in the above reaction?

A.

oxidized

B.

a reactant

C.

reduced

D.

a metal

Correct answer is A

-Zn is a reducing agent, HCl is an oxidizing agent.

-the zinc is oxidized

208.

N\(_2\)O\(_4\) ⇔ 2NO\(_2\)          (Δ = -ve)

From the reaction above, which of these conditions would produce the highest equilibrium yield for N\(_2\)O\(_4\)?

A.

Low temperature and high pressure

B.

Low temperature and low pressure

C.

high temperature and low pressure

D.

high temperature and high pressure

Correct answer is D

high temperature and high pressure favor the highest yield for N\(_2\)O\(_4\)

high temperature favours the production of the reactant since it is endothermic, while high pressure favours the side involving a decrease in volume.

209.

An organic compound with fishy smell is likely to have a general formula?

A.

RCONHR\(^1\)

B.

RCONH\(_2\)

C.

RNH\(_2\)

D.

RCOR\(^1\)

Correct answer is C

Amines possess a characteristic ammonia smell, liquid amines have a distinctive "fishy" and foul smell. 

-Amine. R-NH2

210.

Using the metal activity series, the metal that can liberate hydrogen gas from steam is?

A.

iron

B.

copper

C.

tin

D.

lead

Correct answer is A

Iron reacts with steam to form iron oxide and hydrogen gas.