English Medium Class 10 - CBSE Question Bank Solutions for Science

Give an example of a double displacement reaction other than the one given in the following Activity.
•Take about 3 mL of sodium sulphate
solution in a test tube.
• In another test tube, take about 3 mL of
barium chloride solution.
• Mix the two solutions given in the following fig.
• What do you observe?

Write the balanced chemical equation for the following and identify the type of reaction. 

\[\ce{Potassium bromide (aq) + Barium iodide (aq) -> Potassium iodide (aq) + Barium bromide (s)}\]

What is the difference between displacement and double displacement reactions? Write equations for these reactions.

What do you mean by a precipitation reaction? Explain giving an example.

A person needs a lens of power -5.5 dioptres for correcting his distant vision. For correcting his near vision he needs a lens of power +1.5 dioptre. What is the focal length of the lens required for correcting (i) distant vision and (ii) near vision?

What is observed when a solution of sodium sulphate is added to a solution of barium chloride taken in a test tube? Write equation for the chemical reaction involved and name the type of reaction in this case.

Give two characteristics of the chemical reaction which occurs on adding potassium iodide solution to lead nitrate solution.

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

\[\ce{PQ + RS -> PS + RQ}\]

What type of reaction is represented by the following equation?

\[\ce{CuSO4 + 2NaOH -> Cu(OH)2 + Na2SO4}\]

What is meant by a double displacement reaction? Explain with the help of one example.

What happens when silver nitrate solution is added to sodium chloride solution?
 Name the type of reaction involved.

1. What happens when an aqueous solution of sodium sulphate reacts with an aqueous solution of barium chloride?
2. Write the balanced chemical equation for the reaction which takes place.
3. State the physical conditions of reactants in which the reaction will not take place.
4. Name the type of chemical reaction which occurs.
5. Give one example of another reaction which is of the same type as the above reaction.

Consider the reaction:

\[\ce{KBr_{(aq)} + AgNO3_{(aq)} -> KNO3_{(aq)} + AgBr_{(s)}}\]

This is an example of:

A metal X forms a water soluble salt XNO₃. When an aqueous solution of XNO₃ is added to common salt solution, then a white precipitate of compound Y is formed along with sodium nitrate solution. Metal X is said to be the best conductor of electricity and it does not evolve hydrogen when put in dilute hydrohloric acid.

1. What is metal X?
2. What is salt XNO₃?
3. Name the compound Y.
4. Write the chemical equation of the reaction which takes place on reacting XNO₃ solution and common salt solution giving the physical states of all the reactants and products.
5. What type of chemical reaction is illustrated by the above equation?

A red-brown metal X forms a salt XSO₄. When hydrogen sulphide gas is passed through an aqueous solution of XSO₄, then a black precipitate of XS is formed alongwith sulphuric acid solution.

1. What could the salt XSO₄ be?
2. What is the colour of salt XSO₄?
3. Name the black precipitate XS.
4. By using the formula of the salt obtained in (a) above, write an equation of the reaction which takes place when hydrogen sulphide gas is passed through its aqueous solution.
5. What type of chemical reaction takes place in this case?

The aqueous solutions of copper sulphate and zinc sulphate appear

(A) blue and green respectively

(B) green and colourless respectively

(C) blue and brown respectively

(D) blue and colourless respectively.

Solutions of copper sulphate, iron sulphate and zinc sulphate are prepared and marked I, II and III respectively. Few pieces of aluminium are added to each solutions. After some time a change will be observe in

(A) I and II

(B) II and III

(C) III and I

(D) All the three

(i) What is observed when a solution of potassium iodide is added to a solution of lead nitrate taken in a test tube?
(ii) What type of reaction is this?
(iii) Write a balanced chemical equation to represent the above reaction.

When hydrogen sulphide gas is passed through a blue solution of copper sulphate, a black precipitate of copper sulphide is obtained and the sulphuric acid so formed remains in the solution. The reaction is an example of a:

In a double displacement reaction such as the reaction between sodium sulphate solution and barium chloride solution:

1. exchange of atoms takes place
2. exchange of ions takes place
3. a precipitate is produced
4. an insoluble salt is produced

The correct option is: