English Medium Class 10 - CBSE Question Bank Solutions

What are anti-oxidants?

Identify in the following reaction (a) the substance oxidised, and (b) the substance reduced:

\[\ce{ZnO + C -> Zn + CO}\]

In the following reaction between lead sulphide and hydrogen peroxide:

\[\ce{PbS_{(s)} + 4H2O2_{(aq)} -> PbSO4_{(s)} + 4H2O_{(l)}}\]

1. Which substance is reduced?
2. Which substance is oxidised?

Identify the component oxidised in the following reaction:

\[\ce{H2S + Cl2 -> S + 2HCl}\]

When SO₂ gas is passed through saturated solution of H₂S, the following reaction occurs:

\[\ce{SO2 + 2H2S -> 2H2O + 3S}\]

In this reaction, which substance is oxidised and which one is reduced?

The addition of oxygen to a substance is called ______ whereas removal of oxygen is called ______.

The addition of hydrogen to a substance is called ______ whereas removal of hydrogen is called ______.

When a magnesium ribbon burns in air with a dazzling flame and forms a white ash, is magnesium oxidised or reduced? Why?

In the reaction represented by the equation:

\[\ce{MnO2 + 4HCl -> MnCl2 + 2H2O + Cl2}\]

1. name the substance oxidised.
2. name the oxidising agent.
3. name the substance reduced.
4. name the reducing agent.

Give an example of an oxidation reaction.

Is oxidation an exothermic or an endothermic reaction?

Give one example of an oxidation-reduction reaction which is also a combination reaction.

Give one example of an oxidation-reduction reaction which is also a displacement reaction.

Explain the following in terms of gain or loss of oxygen with one example:

Oxidation

Explain the following in terms of gain or loss of oxygen with one example:

Reduction

When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name

1. substance oxidised, and
2. substance reduced.

Define the following in terms of gain or loss of hydrogen with one example:

Oxidation

Define the following in terms of gain or loss of hydrogen with one example:

Reduction

When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name

1. substance oxidised, and
2. substance reduced.

In the reaction represented by the following equation:

\[\ce{CuO_{(s)} + H2_{(g)} -> Cu_{(s)} + H2O_{(l)}}\]

1. name the substance oxidised
2. name the substance reduced
3. name the oxidising agent
4. name the reducing agent