JAMB Chemistry Past Questions & Answers - Page 296

1,476.

The gas formed when ammonium trioxonitrate (V) is heated with sodium hydroxide is?

A.

hydrogen

B.

nitrogen (IV) oxide

C.

oxygen

D.

ammonium

Correct answer is D

No explanation has been provided for this answer.

1,477.

Which of the following oxides of nitrogen is unstable in air?

A.

NO2

B.

NO

C.

N2O4

D.

N2O5-

Correct answer is B

No explanation has been provided for this answer.

1,478.

Which of the following combination of gases is used for metal welding? i. Oxygen and ethyne, ii. Hydrogen and ethyne, iii. Hydrogen and oxygen, iv. Ethyne, hydrogen and oxygen.

A.

i and ii

B.

ii and iv

C.

i and iii

D.

ii and iv

Correct answer is C

Oxyhydrogen is a mixture of hydrogen and oxygen gases.

This gaseous mixture is used for torches to process refractory materials and was the first gaseous mixture used for welding.

A gas torch that burns a mixture of acetylene and oxygen to produce a high-temperature flame (3,000°C or 5,400°F) that can weld or cut metal.

1,479.

Which of these statements is TRUE about carbon (IV) oxide?

A.

it supports combustion

B.

It is strongly acidic in water

C.

It is very soluble in water

D.

It supports the buring of magnesium to produce magnesium oxide

Correct answer is C

Carbon(iv)oxide does not burn, nor support the combustion of most substance . 

The intense heat produced by burning magnesium,

However, decomposes Carbon(iv)oxide to release oxygen for the further oxidation of magnesium.

Carbon(iv)oxide dissolves in water to form trioxocarbonate(iv) acid ( soda water).

1,480.

For a general equation of the nature xP + yQ ≈ mR + nS, the expression for the equilibrium constant is?

A.

k (p)x (Q)y

B.

(p)x (Q)y / (R)m (S)n

C.

(R)m (S)n / (p)x (Q)y

D.

m(R) n (S) / x(P) y (Q)

Correct answer is C

No explanation has been provided for this answer.