English Medium इयत्ता १० - CBSE Question Bank Solutions for Science

The white solid compound A decomposes quite rapidly on heating in the presence of a black substance X to form a solid compound B and a gas C. When an aqueous solution of compound B is reacted with silver nitrate solution, then a white precipitate of silver chloride is obtained along with potassium nitrate solution. Gas C does not burn itself but helps burn other things.

1. What is compound A?
2. What is compound B?
3. What is gas C?
4. What do you think is the black substance X? What is its function?
5. What is the general name of substances like X?

What type of reaction is represented by the digestion of food in our body?

State an important use of decomposition reactions.

Give one example of a decomposition reaction which is carried out by applying heat.

Give one example of a decomposition reaction which is carried out with electricity.

What type of chemical reaction is used to extract metals from their naturally occurring compounds like oxides or chlorides?

What type of reaction is represented by the following equation?

\[\ce{CaCO3 -> CaO + CO2}\]

What type of reaction is represented by the following equation?

\[\ce{2FeSO4 -> Fe2O3 + SO2 + SO3}\]

What type of reaction is represented by the following equation?

\[\ce{NH4Cl -> NH3 + HCl}\]

What type of chemical reaction takes place when limestone is heated?

What type of chemical reaction takes place when silver bromide is exposed to sunlight?

What type of chemical reaction takes place when electricity is passed through water?

What type of chemical reaction is represented by the following equation?

\[\ce{X -> Y + Z}\]

What type of reaction is represented by the following equation?

\[\ce{NH4NO2 -> N2 + 2H2O}\]

What is the colour of ferrous sulphate crystals? How does this colour change after heating?

Name the product formed on strongly heating ferrous sulphate crystals. What type of chemical reaction occurs in this change?

What is meant by a decomposition reaction?

State the change in colour observed in the following case, mentioning the reason:

Silver chloride is exposed to sunlight.

Which of the following can be decomposed by the action of light?

When a green iron salt is heated strongly, its colour finally changes to brown and odour of burning sulphur is given out.

1. Name the iron salt.
2. Name the type of reaction that takes place during the heating of iron salt.
3. Write a chemical equation for the reaction involved.