JAMB Chemistry Past Questions & Answers - Page 148

736.

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.

737.

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.

738.

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.

739.

A jet plane carrying 3,000 kg of ethane burns off all the gas forming water and carbondioxide. if all the carbondioxide is expelled and all the water formed is condensed and kept on board the plane, then the gain in weight is

A.

1,800 kg

B.

900 kg

C.

600 kg

D.

2,400 kg

E.

1,200 kg

Correct answer is D

2\(C_2H_6 + 7O_2 →4CO_2 + 6H_2O\)

addition of oxygen causes weight gain, expelled \(CO_2\) results in weight loss

for oxygen added;

2moles \(C_2H_6\) = 7moles \(O_2\)

2(30)g  \(C_2H_6\) = 7(2)(16)g \(O_2\)

3000kg  \(C_2H_6\) = X kg \(O_2\)

cross multiplying X = 11200kg

for \(CO_2\) expelled;

2moles  \(C_2H_6\) = 4moles \(CO_2\)

2(30)g  \(C_2H_6\) = 4(44)g  \(CO_2\)

3000kg \(C_2H_6\) = Y kg  \(CO_2\)

cross multiplying Y = 8800kg

since X > Y, the plane has a net weight gain.

Net weight gain = X - Y = 11200-8800 = 2400kg.

740.

Which of the following is a neutralization reaction?

A.

Addition of sodium chloride solution to potassium chloride solution

B.

Addition of trioxonitrate (V) acid (nitric acid) to distilled water

C.

Addition of trioxonitrate (V) acid (nitric acid) to tetraoxosulphate (IV) acid (sulphuric acid)

D.

Addition of trioxonitrate (V) acid (nitric acid) to potassium trioxonitrate (V) (potassium nitrate) solution

E.

Addition of trioxonitrate (V) acid (nitric acid) to potassium hydroxide solution

Correct answer is E

No explanation has been provided for this answer.