JAMB Chemistry Past Questions & Answers - Page 329

1,641.

N2O4(g) ↔ 2NO2(g) ΔH = +ve
In the reaction above, an increase in temperature will

A.

increase the value of the equilibrium constant

B.

decreases the value of the equilibrium constant

C.

increase in the reactant production

D.

shift the equilibrium to the left

Correct answer is A

No explanation has been provided for this answer.

1,642.

Which of the following noble gases is commonly found in the atmosphere?

A.

Xenon

B.

Neon

C.

Helium

D.

Argon

Correct answer is D

Argon, with the symbol Ar which is the third noble gas, in group 18 makes up about 1% of the Earth's atmosphere, making it the most common noble gas on Earth.

1,643.

A suitable solvent for iodine and naphthalene is

A.

carbon (IV) sulphide

B.

ethanol

C.

water

D.

benzene

Correct answer is B

No explanation has been provided for this answer.

1,644.

Hardness of water is mainly due to the presence of

A.

calcium hydroxide or magnesium hydroxide

B.

calcium trioxocarbonate (IV) or calcium tetraoxosulphate (VI)

C.

sodium hydroxide or magnesium hydroxide

D.

calcium chloride or sodium chloride salts

Correct answer is B

Salts of Calcium and Magnesium are responsible for hardness of water. Bicarbonates, Carbonates, Chlorides and Sulfates of Calcium and Magnesium causes temporary and permanent hardness.

1,645.

What type of bond exits between an element X with atomic number 12 and Y with atomic number 17?

A.

Electrovalent

B.

Metallic

C.

Covalent

D.

Dative

Correct answer is A

No explanation has been provided for this answer.