JAMB Chemistry Past Questions & Answers - Page 380

1,896.

An isomer of C5H12 is

A.

Butane

B.

2 – methylbutane

C.

2 – methylpropane

D.

2 – ethylbutane

Correct answer is B

Isomers of Pentane include : 2 methyl-butane and 2-Dimethylpropane.

So Option B is most viable.

1,897.

The alkyl group can be represented by the general formula

A.

CnH2n+1

B.

CnH2n

C.

CnH2n+2

D.

CnH2n-2

Correct answer is A

No explanation has been provided for this answer.

1,898.

Oxyacetylene flame is used for iron-welding because it

A.

Makes the iron metals solidify very quickly

B.

Combines with oxygen to give a pop sound

C.

Evolves a lot of heat when burnt

D.

Dissociates to produce carbon (IV) oxide and oxygen

Correct answer is C

No explanation has been provided for this answer.

1,899.

Sodium metal is always kept under oil because it

A.

Readily reacts with water

B.

Is reduced by atmospheric nitrogen

C.

Reacts vigorously on exposure to air

D.

Reacts with oxygen and carbon (IV) oxide

Correct answer is C

No explanation has been provided for this answer.

1,900.

Transition metals possess variable oxidation states because they have

A.

Electrons in the d orbitals

B.

Electron in the s orbitals

C.

A variable number of electrons in the p orbitals

D.

Partially filled p orbitals

Correct answer is A

No explanation has been provided for this answer.