WAEC Past Questions and Answers - Page 1811

9,051.

Which of the following formula is that of a dicarboxylic acid?

A.

(CH3CH 2)2CHCOOH

B.

CH2(OH)2

C.

CH3CH(OH)COOH

D.

CH2(COOH)2

E.

CH3COCOOH

Correct answer is D

No explanation has been provided for this answer.

9,052.

Brass is an alloy of copper and

A.

iron

B.

chromium

C.

zinc

D.

tin

E.

magnesium

Correct answer is C

No explanation has been provided for this answer.

9,053.

CH2 = CH2 + H2SO4 → CH3 - CH2 -OSO3H. The reaction illustrated by the equation above is an example of

A.

substitution

B.

oxidation

C.

reduction

D.

addition

E.

displacement

Correct answer is D

No explanation has been provided for this answer.

9,054.

Which of the following elements can from more than one acidic oxide?

A.

Hydrogen

B.

Sulphur

C.

Carbon

D.

Alumium

E.

Iron

Correct answer is B

No explanation has been provided for this answer.

9,055.

Which of the processes represented by the following equations has the greatest positive entropy change?

A.

C6H3(l) → C6H 6 (g)

B.

H2O (s) → H2O(l)

C.

CuO(s) + H2(g) → Cu(s) + H2

D.

Na2CO3(s) + nH2O(l) →Na 2CO3nH2O(s)

E.

S(s) → S(l)

Correct answer is A

we have the greatest entropy when a substance changes from the liquid phase to the gaseous phase this is because the particles of gases are very loosely packed so they have the freedom to move around.