CIE Chemistry (US-0439): Specimen Questions with Answers 220 - 222 of 240

Question number: 220

MCQ▾

Question

For purification of common salt we use ________ acid.

Choices

Choice (4) Response

a.

Sulphuric acid

b.

Vinegar

c.

Nitric acid

d.

Hydrochloric acid

Answer

d.

Explanation

For purification of common salt we use hydrochloric acid.

Question number: 221

MCQ▾

Question

The equation shows the formation of from .

Statements refer to this reaction.

1. sulfate is reduced to sulfate.

2. The (II) in the name refers to the oxidation state of the metal.

3. The reaction is reversible.

Which statements are correct?

Choices

Choice (4) Response

a.

b.

c.

d.

Answer

d.

Explanation

Correct option is D i. e. only (The reaction is reversible) because water driven is off from anhydrous Copper sulfate and endothermic energy is done and when it heated it form again forms anhydrous copper sulfate. So the reaction is reversible.

Question number: 222

MCQ▾

Question

Iron rusts when it reacts with …………

Rusting can be prevented by covering the iron with a more reactive metal, such as ………… Which words correctly complete gaps 1 and 2?

Choices

Choice (4) Response

a.

Image of Iron rust:Choice A

Image of Iron Rust: Choice A

Image of Iron rust: Choice A

b.

Image of Iron rust:Choice B

Image of Iron Rust: Choice B

Image of Iron rust: Choice B

c.

Image of Iron rust:Choice C

Image of Iron Rust: Choice C

Image of Iron rust: Choice C

d.

Image of Iron rust:Choice D

Image of Iron Rust: Choice D

Image of Iron rust: Choice D

Answer

d.

Explanation

Correct option is D because iron rust when it react with oxygen and water and it can be prevented by magnesium not copper better because magnesium is more reactive than copper.