Tuesday, 12 March 2013

ncert solutions class 10 science chapter 1 Chemical reactions and equations



  • All Definitions with examples
  • Solution of all Text Question
  • Exercise solutions  

    • (Text Solutions Given below these Video Solutions)

    Chemical Equations
    Balanced Chemical equation
    Combination Reaction
    Decomposition reaction
    Displacement Reaction
    Double displacement reaction
    Precipitation Reaction
    Oxidation Reaction
    Reduction Reaction
    Redox Reaction or Oxidation-Reduction reaction
    Corrosion
    Rancidity 

    In text questions page number 6

    (i) Hydrogen + Chlorine  Hydrogen chloride
    (ii) Barium chloride + Aluminium sulphate   Barium sulphate + Aluminium chloride
    (iii) Sodium + Water   Sodium hydroxide + Hydrogen
    3. Write a 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 the solution of sodium chloride.
    (ii) Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) to produce sodium chloride solution and water.
    In text questions page number 10

    1. A solution of a substance ‘X’ is used for white washing.
    (i) Name the substance ‘X’ and write its formula.
    (ii) Write the reaction of the substance ‘X’ named in (i) above with water.
    2. Why is the amount of gas collected in one of the test tubes in Activity 1.7 double of the amount collected in the other? Name this gas.

    In text questions page number 13

    Text Book Exercise
    Question 1. Which of the statements about the reaction below are incorrect?
    2PbO(s) + C(s) → 2Pb(s) + CO 
    (a) Lead is getting reduced. 
    (b) Carbon dioxide is getting oxidised. 
    (c) Carbon is getting oxidised. 
    (d) Lead oxide is getting reduced. 
    (i) (a) and (b) 
    (ii) (a) and (c) 
    (iii) (a), (b) and (c) 
    (iv) all
     
    The above reaction is an example of a
    (a) combination reaction.
    (b) double displacement reaction. 
    (c) decomposition reaction.
    (d) displacement reaction.
    Question 3. What happens when dilute hydrochloric acid is added to iron fillings? Tick the correct answer. 
    (a) Hydrogen gas and iron chloride are produced.
    (b) Chlorine gas and iron hydroxide are produced.
    (c) No reaction takes place.
    (d) Iron salt and water are produced.
    Question 4. What is a balanced chemical equation? Why should chemical equations be balanced?
    Question 5. Translate the following statements into chemical equations and then balance them.
    (a) Hydrogen gas combines with nitrogen to form ammonia.
    (b) Hydrogen sulphide gas burns in air to give water and sulpur dioxide.
    (c) Barium chloride reacts with aluminium sulphate to give aluminium chloride and a precipitate of barium sulphate. 
    (d) Potassium metal reacts with water to give potassium hydroxide and hydrogen gas.
    Question 7. Write the balanced chemical equations for the following reactions. 
    (a) Calcium hydroxide + Carbon dioxide → Calcium carbonate + Water
    (b) Zinc + Silver nitrate → Zinc nitrate + Silver
    (c) Aluminium + Copper chloride → Aluminium chloride + Copper
    (d) Barium chloride + Potassium sulphate → Barium sulphate + Potassium chloride
    Question 8. Write the balanced chemical equation for the following and identify the type of reaction in each case. 
    (a) Potassium bromide (aq) + Barium iodide (aq) → Potassium iodide (aq) + Barium bromide(s) 
    (b) Zinc carbonate(s) → Zinc oxide(s) + Carbon dioxide(g)
    (c) Hydrogen(g) + Chlorine(g)  →  Hydrogen chloride(g)
    (d) Magnesium(s) + Hydrochloric acid(aq)  →  Magnesium chloride(aq) + Hydrogen(g)
    Question 11. Why are decomposition reactions called the opposite of combination reactions? 
    Write equations for these reactions.
    Question 12. Write one equation each for decomposition reactions where energy is supplied in the form of heat, light or electricity.
    Question 13. What is the difference between displacement and double displacement reactions? Write equations for these reactions.
    Question 14.  In the refining of silver, the recovery of silver from silver nitrate solution involved displacement by copper metal. Write down the reaction involved.
    Question 16. Explain the following in terms of gain or loss of oxygen with two examples each. 
    (a) Oxidation
    (b) Reduction
    Question 17. A shiny brown coloured element ‘X’ on heating in air becomes black in colour. Write the name the element ‘X’ and the black coloured compound formed.

     

    Posted by at
    Labels:

    1 comment:

    1. Unknown20 January 2014 at 02:45

      This comment has been removed by a blog administrator.

      ReplyDelete

    Subscribe to: Post Comments (Atom)