JAMB Chemistry Past Questions & Answers - Page 191

951.

Carbohydrates are large molecules with the molecular formula C\(_x\)(H\(_2\)O)\(_y\). In which of the following pairs is x not equal to y?

A.

glucose and starch

B.

maltose and starch

C.

sucrose and fructose

D.

galactose and starch

Correct answer is B

Glucose = C\(_6\)(H\(_2\)O)\(_6\)

= C\(_6\)H\(_{12}\)O\(_6\)

Maltose = C\(_{12}\) (H\(_2\)O)\(_{11}\)

= C\(_{12}\)H\(_{22}\)O\(_{11}\)

Starch = C\(_6\) (H\(_2\)O)\(_5\)

= C\(_6\)H\(_{10}\)O\(_5\)

Sucrose = C\(_{12}\) (H\(_2\)O)\(_{11}\)

= C\(_{12}\)H\(_{22}\)O\(_{11}\)

Fructose = C\(_6\)(H\(_2\)O)\(_6\)

= C\(_6\)H\(_{12}\)O\(_6\)

 

952.

The isomers of C3H8O ARE

A.

1 - propanol and 2 - propanol

B.

1 - propanol and 1 - propanol

C.

2 - propanol and 2 - propanone

D.

2 - propanol and 1 - propanol

Correct answer is A

No explanation has been provided for this answer.

953.

Alkanals can be distinguished from alkanones by the reaction with

A.

sudan lll stain

B.

starch iodide paper

C.

lithium tetrahydrido aluminate (lll)

D.

fehling's solution

Correct answer is D

No explanation has been provided for this answer.

954.

Geometric isomerism can exist in

A.

hex-3-ene

B.

hexane

C.

prop-l-ene

D.

3-methyl but -l-ene

Correct answer is A

No explanation has been provided for this answer.

955.

Which of the following metals is the least reactive?

A.

Pb

B.

Sn

C.

Hg

D.

Au

Correct answer is D

No explanation has been provided for this answer.