English Medium Class 10 - CBSE Question Bank Solutions for Science

Write a chemical equation to show the process of corrosion of iron.

 What special name is given to their corrosion of iron?

What type of chemical reaction is involved in the corrosion of iron?

Name any three objects (or structures) which are gradually damaged by the corrosion of iron and steel.

(a) What happens when an aqueous solution of sodium sulphate reacts with an aqueous solution of barium chloride?
(b) Write the balanced chemical equation for the reaction which takes place.
(c) State the physical conditions of reactants in which the reaction will not take place.
(d) Name the type of chemical reaction which occurs.
(e) Give one example of another reaction which is of the same type as the above reaction.

The chemical reaction involved in the corrosion of iron metal is that of:
(a) oxidation as well as displacement
(b) reduction as well as combination
(c) oxidation as well as combination
(d) reduction as well as displacement

Consider the reaction:

KBr (aq) + AgNO₃ (aq) → KNO₃ (aq) + AgBr (s)

This is an example of:
(a) decomposition reaction
(b) combination reaction
(c) double displacement reaction
(d) displacement reaction

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 alongwith 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.
(a) What is metal X?
(b) What is salt XNO₃?
(c) Name the compound Y.
(d) 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. 
(e) 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.
(a) What could the salt XSO₄ be?
(b) What is the colour of salt XSO₄?
(c) Name the black precipitate XS.
(d) 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.
(e) What type of chemical reaction takes place in this case?

(i) A ray of white light breaks up into its components while passing through a glass prism. Draw a ray diagram to show the path of rays.
(ii) Mark the least deviated colour in your  diagram 

(iii) Why do different coloured rays deviate differently in a prism?

As light rays pass from air into a glass prism, are they refracted towards or away from the normal?

As light rays emerge from a glass prism into air, are they refracted towards or away from the normal?

In the formation of spectrum of white light by a prism: 

 which colour is deviated least?

In the formation of spectrum of white light by a prism:

 which colour is deviated most?

Fill in the blank with suitable word: 

When a ray of light enters a prism, it bends ................ the normal ; as it leaves the prism, it bends ................. the normal.

 What happens when a ray of ordinary light is passed through a triangular glass prism?

 What will happen if another similar glass prism is placed upside down behind the first prism?

When a beam of white light is passed through a prism, it splits to form lights of seven colours. Is it possible to recombine the lights of seven colours to obtain the white light again? Explain your answer.

 What is spectrum? What is the name of glass shape used to produce a spectrum?

In the figure given alongside, a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism, it produces a spectrum YX on the screen.  

State the colour seen (i) at X, and (ii) at Y.