JAMB Chemistry Past Questions & Answers - Page 55

271.

The IUPAC name of the compound CF\(_3\)CHBrCl is

A.

2-chloro-2-bromo-1,1,1-trifluoroethane

B.

2-bromo-2-chloro-1,1,1-trifluoroethane

C.

1-bromo-1-chloro-2,2,2-trifluoroethane

D.

1,1,1-trifluoro-2-bromo-2-chloroethane

Correct answer is B

No explanation has been provided for this answer.

272.

Hydrocarbons which will react with Tollen's reagent conform to the general formula

A.

C\(_n\)H\(_{2n}\)

B.

C\(_n\)H\(_{2n + 2}\)

C.

C\(_n\)H\(_{2n - 2}\)

D.

C\(_n\)H\(_{2n + 1}\)OH

Correct answer is D

No explanation has been provided for this answer.

273.

2-methylprop-1-ene is an isomer of?

A.

3-methyl but-1-ene

B.

2-methyl but-1-ene

C.

but-2-ene

D.

pent-2-ene

Correct answer is C

somers of Butene: are But-1-ene, But-2-ene, 2-Methylpropene / 2-methylprop-1-ene

274.

A certain hydrocarbon on complete combustion at s.t.p produced 89.6dm\(^3\) of CO\(_2\) and 54g of water. The hydrocarbon should be?

A.

C\(_6\)H\(_6\)

B.

C\(_4\)H\(_{10}\)

C.

C\(_5\)H\(_{10}\)

D.

C\(_4\)H\(_6\)

Correct answer is D

C\(_x\)H\(_y\) + (x + y/4)O\(_2\) \(\to\) x CO\(_2\) + y/2 H\(_2\)O

89.6 dm\(^3\) \(\to\) x moles CO\(_2\)

22.4 dm\(^3\) \(\to\) 1 mole CO\(_2\)

x = \(\frac{89.6}{22.4}\)

= 4 moles CO\(_2\)

54g of H\(_2\)O \(\to\) k moles H\(_2\)O

18g H\(_2\)O \(\to\) 1 mole H\(_2\)O

k = \(\frac{54}{18}\)

= 3 moles H\(_2\)O

From the equation above,

x = 4 

k = y/2 = 3

y/2 = 3 \(\implies\) y = 6

\(\therefore\) The hydrocarbon C\(_x\)H\(_y\) = C\(_4\)H\(_6\)

275.

The IUPAC name for CH\(_3\)CH\(_2\)COOCH\(_2\)CH\(_3\) is

A.

methylpropanoate

B.

ethylethanoate

C.

ethylpropanoate

D.

methylethanoate

Correct answer is C

No explanation has been provided for this answer.