JAMB Chemistry Past Questions & Answers - Page 358

1,786.

Copper and silver metals are commonly use as coin because they are

A.

easily reduced

B.

not easily reduced

C.

easily oxidized

D.

not easily oxidized

Correct answer is D

No explanation has been provided for this answer.

1,787.

Cu2+(aq) + 4NH3(g) ↔ [Cu(NH3)4]2+(aq)
In the reaction above, what is the effect of precipitating Cu2+(aq) as CuS(s)?

A.

NH3(g) concentration will decrease

B.

more NH3(g)

C.

The equilibrium will shift to the right

D.

There will be no effect

Correct answer is B

No explanation has been provided for this answer.

1,788.

The tincture of iodine means iodine dissolved in

A.

ethanol

B.

bromine chloride

C.

chlorine water

D.

water

Correct answer is A

No explanation has been provided for this answer.

1,789.

Na2S2O3(aq) + 2HCl(aq) → 2NaCl(aq) + H2O(l)
Which of the following would introduce the greatest increase in the rate of the chemical reaction above?

A.

An increase in temperature and decrease in the concentration of the reactant

B.

A decrease in the volume and increase in the pressure of the reactant

C.

A decrease in the temperature and an incease in the concentration of the reactant

D.

An increase in temperature and an increase in the concentration of the reactant

Correct answer is D

No explanation has been provided for this answer.

1,790.

The reddish-brown rust on iron roofing sheets consists of

A.

Fe3+(H2O)6

B.

FeO.H2O

C.

Fe2O3.3H2O

D.

Fe3O4.2H2O

Correct answer is C

No explanation has been provided for this answer.