WAEC Past Questions and Answers - Page 1759

8,791.

Which of the following would increase the rate of reaction of chips of a metal M as shown in the equation below? M(s) + 2HCI(aq) → MCI2(aq) + H2(g)

A.

Diluting the hydrochloric acid

B.

Adding some distilled water

C.

Decreasing the temperature

D.

Grinding the metal into powder

E.

Increasing the pressure

Correct answer is D

No explanation has been provided for this answer.

8,792.

Which of the following is not a property of magnesium oxide?

A.

High melting point

B.

Dissolution in polar solvents

C.

Presence of ionic bonds

D.

Possession of crystal lattice

E.

Low binding energy

Correct answer is E

No explanation has been provided for this answer.

8,793.

In any chemical reaction, the total mass of the products is always equal to that of the reactants. This is statement of the law of

A.

definite proportion

B.

conservation of matter

C.

reciprocal proportions

D.

constant composition

Correct answer is B

No explanation has been provided for this answer.

8,794.

A measure of the degree of disorder in a chemical system is known as the

A.

enthalpy

B.

free energy

C.

activation energy

D.

entrophy

E.

equilibrium

Correct answer is D

No explanation has been provided for this answer.

8,795.

Catalytic hydrogenation of alkenes produces compounds with the general formula

A.

CnH2n+1 OH

B.

CnH2n+1

C.

CnH2n+2

D.

CnH2n-2

E.

Cx(H2O)y

Correct answer is C

In a hydrogenation reaction, two hydrogen atoms are added across the double bond of an alkene, resulting in a saturated alkane