JAMB Chemistry Past Questions & Answers - Page 135

671.

The I.U.P.A.C name for the compound is

A.

isopropylethene

B.

acetylene

C.

3- methylbutane

D.

2-methylbutane

E.

5-methylpentane

Correct answer is D

No explanation has been provided for this answer.

672.

Use the diagram above to answer this question Which of the following structural formula is NOT isomeric with the others?

A.

A

B.

B

C.

C

D.

D

E.

E

Correct answer is D

Isomers have the same molecular structures(but different structures). so whatever the structures are, they must contain the same amount of carbon, the same amount of hydrogen, and the same amount of oxygen as in this case. Just count the number of hydrogens (including the hydrogen in OH). you should get 10 hydrogens from A, B, C, and E. in total, you should have C4H10O. options A, B, C, and E have this in common. but the option D has only C4H8O.

673.

USE THE DIAGRAM ABOVE TO ANSWER THIS QUESTION. Which of the following represents a carboxylic acid?

A.

A

B.

B

C.

C

D.

D

E.

E

Correct answer is A

A carboxylic acid is an organic acid that contains a carboxyl group attached to an R-group. The general formula of a carboxylic acid is R−COOH or R−CO₂H, with R referring to the alkyl, alkenyl, aryl, or other group.

674.

The name of the compound above is

A.

acetic acid

B.

propanal

C.

propanol

D.

ethanoic acid

E.

propanoic acid

Correct answer is E

the compound is propanoic acid, it contains the carboxyl group COOH.

675.

The diagram above (Fig.3) shows the energy profile for the reaction A + B + = C + D From this diagram, it is clear that the reaction is

A.

spontaneous

B.

isothermal

C.

adiabatic

D.

exothermic

E.

endothermic

Correct answer is D

No explanation has been provided for this answer.