JAMB Chemistry Past Questions & Answers - Page 214

1,066.

In which of the following is the oxidation state of oxygen different from its value in water?

A.

OH-

B.

H3O+

C.

O-

D.

H2O2

E.

SO2

Correct answer is D

No explanation has been provided for this answer.

1,067.

When dilute hydrochloric acid is added to iron(ll)sulphide, the gas evolved will?

A.

turn moist red litmus paper blue

B.

turn lime water milky

C.

blacken lead acetate paper

D.

rekindle a glowing splint

E.

burn a sqeakly pop

Correct answer is C

The gas liberated is H\(_2\)S which  in the presence of  lead acetate paper gives a black coloration

1,069.

Which of the following is acceptable as the organic product of the reaction of ethanoic acid and ethanol with an acid catalyst?

A.

Ethyl ethanoate

B.

Methyl ethanoate

C.

Ethyl methyl ketone

D.

Butanol

E.

None

Correct answer is A

This is an ESTERIFICATION REACTION of Alkanoic acid and Alkanol to yield an Ester

1,070.

20 cm3 of 1 M H\(_2\)SO\(_4\) is mixed 20 cm\(^3\) of 1 M NaOH. The resulting solution is?

A.

acidic with a molarity of 0.50 M H2SO4

B.

acidic with a molarity of 0.25 H2SO4

C.

neutral

D.

alkaline with a molarity of 0.25 M NaOH

E.

alkaline with a molarity of 0.50 M NaOH

Correct answer is A

The balanced equation for the reaction is:

\(2NaOH + H_2 SO_4 \to Na_2 SO_4 + 2H_2 O\)

\(\therefore 1M H_2 SO_4 \to 2M NaOH\)

\(1M NaOH \to 0.5M H_2 SO_4\)

The resulting solution is Acidic with 0.5M H\(_2\)SO\(_4\).