CIE Chemistry (US-0439): Specimen Questions with Answers 101 - 104 of 240

Question number: 101

MCQ▾

Question

The number of valence electrons equals the ________ number of the element.

Choices

Choice (4) Response

a.

Group

b.

Period

c.

All of the above

d.

None of the above

Answer

a.

Explanation

The number of valence electrons equals the ‘group’ number of the element.

Question number: 102

Short Answer Question▾

Write in Short

Malonic acid reacts with ethanol to form a colorless liquid which has a ‘fruity’ smell. Its structural formula is given below.

Image of ‘fruity’ smell.

Image of ‘Fruity’ Smell.

Image of ‘fruity’ smell.

Image of compound contains

Image of Compound Contains

Image of compound contains

What type of compound contains the group which is circled?

[1 Marks]

Image of compound contains

Image of Compound Contains

Image of compound contains

Explanation

Carbonyl: A carbon-oxygen double bond. The carbon atom has two bonds left over that can be attached to other atoms.

Question number: 103

Short Answer Question▾

Write in Short

All metal nitrates decompose when heated. A few form a nitrite and oxygen. Most form the metal oxide, oxygen and a brown gas called nitrogen dioxide

Suggest why the nitrate of the metal, named in (a) (i), decomposes less readily than lead (II) nitrate

[2 Marks]

Explanation

Because lead (II) nitrate is supports heating more than lithium nitrate.

Question number: 104

MCQ▾

Question

In the reaction between and , a pungent smelling gas is formed. Identify the gas.

Choices

Choice (4) Response

a.

b.

c.

d.

Answer

c.

Explanation

The reaction between and occurs as follows:

So we get , i. e. ammonia as a gaseous product.

Now ammonia is a pungent smelling gas.

So the pungent smelling gas produced in the reaction between and is NH3.