English Medium Class 10 - CBSE Question Bank Solutions

When copper powder is heated strongly in air, it forms copper oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.

Define oxidation in terms of gain or loss of hydrogen with one example.

Define reduction in terms of gain or loss of hydrogen with one example.

When a magnesium ribbon is heated, it burns in air to form magnesium oxide. Write a balanced chemical equation for this reaction. Name (i) substance oxidised, and (ii) substance reduced.

In the reaction represented by the following equation: 

CuO (s) + H₂ (g) → Cu (s) + H₂O (1)

(a) name the substance oxidised
(b) name the substance reduced
(c) name the oxidising agent
(d) name the reducing agent

In the context of redox reactions, the removal of hydrogen from a substance is known as:
(a) oxidation
(b) dehydration
(c) reduction
(d) dehydrogenation

In order to prevent the spoilage of potato chips, they are packed in plastic bags in an atmosphere of:
(a) Cl₂
(b) H₂
(c) N₂
(d) O₂

The process of respiration is:
(a)  an oxidation reaction which is endothermic
(b) a reduction reaction which is exothermic
(c) a combination reaction which is endothermic
(d) an oxidation reaction which is exothermic

You are given the following chemical equation:

Mg (s) + CuO (s) → MgO (s) + Cu (s)

This equation represents:
(a) decomposition reaction as well as displacement reaction
(b) combination reaction as well as double displacement reaction
(c) redox reaction as well as displacement reaction
(d) double displacement reaction as well as redox reaction

Identify the substances that are oxidised and the substances that are reduced in the following reaction.

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

 Explain the following in term Reduction of gain or loss of oxygen with two example.

The colours of aqueous solutions of CuSO₄ and FeSO₄ as observed in the laboratory are:

(A) pale green and light blue respectively

(B) light blue and dark green respectively

(C) dark blue and dark green respectively

(D) dark blue and pale green respectively

Explain the following in term of gain or loss of oxygen with two examples.

Oxidation

Explain the following in term of gain or loss of oxygen with two examples.

Reduction

Name and state the rule of determine the direction of force experienced by a current carrying straight conductor placed in a uniform magnetic field which is perpendicular to it. 

Answer the following question.
While studying the dependence of potential difference ( V) across a resistor on the current (I) passing through it, in order to determine the resistance of the resistor, a student took 5 readings for different values of current and plotted a graph between V and t. He got a straight line graph passing through the origin. What does the straight-line signify? Write the method of determining the resistance of the resister using this graph. 

Two bulbs of 100 W and 40 W are connected in series. The current through the 100 W bulb is 1 A. The current through the 40 W bulb will be ______.

The following diagram shows two parallel straight conductors carrying the same current. Copy the diagram and draw the pattern of the magnetic field lines around them showing their directions. What is the magnitude of the magnetic field at a point 'X' which is equidistant from the conductors? Give justification for your answer.

Rusting of iron involves a chemical reaction which is a combination of:

Which of the following statements about the given reaction are correct?

\[\ce{3Fe_{(s)} + 4H2O_{(g)} -> Fe3O4_{(s)} + 4H2_{(g)}}\]

(i) Iron metal is getting oxidised.

(ii) Water is getting reduced.

(iii) Water is acting as the reducing agent.

(iv) Water is acting as oxidising agent.