JAMB Chemistry Past Questions & Answers - Page 139

691.

zn + 2HCl → ZnCl2 + H2

The rate of the above reaction will be greatly increased if

A.

the zinc is in the powered form

B.

a greater volume of the acid is used

C.

a smaller volume of the acid is used

D.

the reaction vessel is immersed in an ice-bath

E.

the zinc is in the form of pellets

Correct answer is A

No explanation has been provided for this answer.

692.

The equilibrium reaction between copper (l) chloride and chlorine at 25oC and 1 atmosphere is represented by the equation:
2CuCl +Cl2 ⇌ 2 CuCl2 ∆H = - 166 KJ. Which of the following statements is TRUE for the reaction, pressure remaining constant?

A.

more CuCl is formed at 40oC

B.

more CuCl2 is formed at 10oC

C.

Less CuCl2 is formed at 10oC

D.

there is no change in the amount of CuCl2 formed at 40oC and10oC

E.

more CuCl is consumed at 40oC

Correct answer is B

No explanation has been provided for this answer.

693.

When sodium dioxonitrate (lll) (NaNO2) dissolves in water, ∆H is positive. The process of dissolution is

A.

exothermic

B.

endothermic

C.

isothermal

D.

isomeric

E.

hygroscopic

Correct answer is B

No explanation has been provided for this answer.

694.

Which of the following statements is FALSE?

A.

Copper (ll) ion can be reduced to copper (l) ion by hydrochloric acid and zinc

B.

Sodium metal dissolves in water giving oxygen

C.

Nitrogen is insoluble in water

D.

Carbondioxide is soluble in water

E.

lead has a higher atomic weight than copper

Correct answer is B

No explanation has been provided for this answer.

695.

Liquid X, reacts with sodium trioxocarbonate (IV) (Na2CO3) to give a gas which turns calcium chloride solution milky X is

A.

Na2SO4(aq)

B.

Kl (aq)

C.

an alkali

D.

an acid

E.

a hydrocarbon

Correct answer is D

No explanation has been provided for this answer.