CIE Chemistry (US-0439): Specimen Questions with Answers 168 - 170 of 240

Question number: 168

MCQ▾

Question

Mineral acids in their pure form are ________ in nature.

Choices

Choice (4) Response

a.

tasty

b.

bitter

c.

soothing

d.

corrosive

Answer

d.

Explanation

Mineral acids in their pure form are ‘corrosive’ in nature. It corrodes surfaces and churns our skins if dropped on our body.

Question number: 169

MCQ▾

Question

In which equation is the underlined substance acting as a reducing agent?

Choices

Choice (4) Response

a.

b.

c.

d.

Answer

c.

Explanation

Correct Answer is A i. e. reducing agent is the substance which itself oxidize and reduce other so carbon mono oxide oxidizes to form carbon di-oxide and reduce . In other reaction the underline substance is acting as oxidizing agent.

Question number: 170

MCQ▾

Question

What information can we gather about the elements present in a group of the modern periodic table when the group number is provided?

Choices

Choice (4) Response

a.

Similar chemical properties

b.

Number of valence electrons

c.

Valency of the elements

d.

All the other options

Answer

d.

Explanation

In the modern periodic table, group number denotes the number of valence electrons present in that group.

As number of valence electrons is known so we can determine the valency of the elements.

As chemical properties of an element depend on the number of valence electrons so we can say that the elements present along a group have similar chemical properties.

For example, elements present in group have electrons in their valence shell.

So the valency of the elements is , i. e. 1.

As elements of group VIIA have valence electrons so they exhibit similar chemical properties.

Hence all the given choices are correct.