Chemical Reactions and Equations Part-1

NCERT solutions for Class 10 Science Chemical Reactions and Equations 

NCERT Class 10 Science Chapter wise Solutions

• 1 – Chemical Reactions and Equations
• 2 – Acids, Bases and Salts
• 3 – Metals and Non-metals
• 4 – Carbon and Its Compounds
• 5 – Periodic Classification of Elements
• 6 – Life Processes
• 7 – Control and Coordination
• 8 – How do Organisms Reproduce?
• 9 – Heredity and Evolution
• 10 – Light Reflection and Refraction
• 11 – Human Eye and Colourful World
• 12 – Electricity
• 13 – Magnetic Effects of Electric Current
• 14 – Sources of Energy
• 15 – Our Environment
• 16 – Management of Natural Resources

NCERT Solutions for Class 10 Science Chemical Reactions and Equations Part 1

1. Why should a magnesium ribbon be cleaned before burning in air?

Ans. Magnesium ribbon is cleaned before burning to remove the protective layer of basic magnesium carbonate from the surface of magnesium ribbon.

NCERT Solutions for Class 10 Science Chemical Reactions and Equations Part 1

2. Write the balance equation for the following reactions Give reasons for the following reactions?

i. Hydrogen + Chlorine → Hydrogen chloride

ii. Barium chloride + Aluminium sulphate → Barium sulphate + Aluminium chloride

iii. Sodium + water → Sodium hydroxide + water

Ans. The chemical equations are as follows-

NCERT Solutions for Class 10 Science Chemical Reactions and Equations Part 1

3. Write the balanced chemical equation with state symbols for the following reactions?

i. Solutions of barium chloride and sodium sulphate in water react to give insoluble barium sulphate and solution of sodium chloride.

ii. Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.

Ans. Balance chemical reaction with state symbols are as follows-

1. A solution of a substance ‘X’ is used for white washing

i. Name the substance ‘X’ and writes its formula.

ii. Write the reaction of the substance ‘X’ named in (i) above with water

Ans. i. The substance whose solution is water is used for white washing is calcium oxide. Its formula is CaO.

ii.

NCERT Solutions for Class 10 Science Chemical Reactions and Equations Part 1

2. Why the amount of gas collected in one of the tubes in Activity 1.7 double of the amount collected in the other? Name this gas.

Ans. The gas which is collected in double the amount in the electrolysis of water experiment is hydrogen. This is because water contains 2 parts of hydrogen element as compared to only 1 part of oxygen element.

1. Why does the colour of copper sulphate solution change when an iron nail is dipped in it?

Ans. When iron nail is dipped in copper sulphate solution, than iron sulphate solution and copper solution and copper metal are formed:

In this reaction, iron displaces copper from copper sulphate solution. The deep blue colour of copper sulphate fades due to the formation of light green solution of iron sulphate.

NCERT Solutions for Class 10 Science Chemical Reactions and Equations Part 1

2. Give an example of a double displacement reaction other than the one given in Activity 1.10.

Ans. An example of double displacement reaction is

NCERT Solutions for Class 10 Science Chemical Reactions and Equations Part 1

3. Identify the substances that are oxidized and the substances that are reduced in the following reactions.

Ans. (i).

In this reaction, Na is oxidized because it combines with O₂ to form Na₂O. O₂ is reduced because it is converted into Na₂O.

(ii).

In this reaction, CuO is reduced because it loses oxygen. H₂ is oxidized because it combines with oxygen of CuO to form water