Calculating Oxidation Number

Q.

The oxidation number of an element can be zero.

1. True

2. False

Q.

The oxidation number of carbon in carbon dioxide is:

1. Can't say

2. some negative number

3. Zero

4. some positive number

Q.

Which of the following elements have the ability to behaves as both oxidising and reducing agents?

1. H₂SO₄

2. SO₂

3. H₂S

4. HNO₃

Q.

$H_2{O}_2$ is used as what?

1. An oxidant only

2. A reductant only

3. An acid only

4. An oxidant, a reductant and an acid

Q.

Which is the weakest oxidising agent among the following?

1. O2

2. I2

3. None of these

4. KMnO4

Q.

Among the following elements, which is the strongest reducing agent?

1. Lithium

2. Beryllium

3. Chlorine

4. Magnesium

Q.

The oxidation state shown by silicon when it combines with strongly electropositive metal is

1. –2

2. –4

3. +4

4. –2

Q.

A reducing agent is a substance which can donate electrons.

1. Accept electron

2. Donate electrons

Q.

In $C+H_{2}O⟶CO+H_2,H_{2}O$ acts as a:

1. Oxidising agent

2. Reducing agent

3. (a) and (b) both

4. None of these

Q.

The oxidation number of sulphur in sulphur dioxide$S{O}_2$ and sulphuric acid$H_{2}S{O}_4$ is respectively

1. +6 and +4

2. +4 and +6

3. +4 and +4

4. +6 and +6