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Tenth chemistry English medium chapter wise notes pdf

Salient features

·         Complete chapter test yourself questions are solved.

·         Exercise Questions are also solved.

·         Exercise multiple choice questions Key also prepared.

Visit 1st chapter notes 

CHAPTER   9                  CHEMICAL EQUILIBRIUM      

Test yourself    9.1

        I.            Why reversible reactions never complete?

BecauBecause these reactions proceed in both ways forward as well as reverse.

      II.            What is static equilibrium, explain with an example?

 When reaction ceases to proceed, it is called static equilibrium. For example a building remains standing rather than falling down because all the forces acting on it are static. This is an example of static equilibrium.

    III.            Why the amount of reactants and products do not change in a reversible reaction?

 At equilibrium state, rate of forward reactions and rate of reverse reactions is equal that is why amount of reactants and products do not change.

Test Yourself   9.2

        I.            Define the law of mass action?

 The rate at which a substance reacts is directly proportional to its active mass and the rate of a reaction is directly proportional to the product of the active masses of the reacting substances.

      II.            How is the active mass represented?

 Active mass is represented as square brackets

 [  ].

    III.            What do you mean by equilibrium constant?

 Equilibrium constant is ratio of the product of concentration of products raised to the power of coefficient to the product of concentration of reactant raised to the power of coefficient as expressed in the balanced chemical equation.

Test Yourself   9.3

        I.            What do you mean by the extent of a reaction?

  Extent of reaction indicates to which extent reactants are converted to products. In fact, it measures how far a reaction proceeds before establishing equilibrium state.

      II.            Why the reversible reactions do not go to completion?

 Because these reactions proceed in both ways forward as well as reverse.

           III.     If a reaction has large value of K_c will it go to completion?

 The large value of K_c indicates that at equilibrium position the reaction mixture consist of almost all products and reactants are negligible. The reaction has almost gone to completion.

           IV.     Which type of reaction does not go to completion?

 Reaction with small value of K_c does not go to completion.

             V.     Why the reaction mixture does not have 50% reactants and 50% products at equilibrium position?

The reaction mixture does not have 50% reactant and 50% product at equilibrium state because concentration of reactant and product depends upon the numerical value of K_c.

               EXERCISE SHORT QUESTIONS

1.       What are irreversible reactions? Give a few characteristics of them?

 Reactions in which products do not recombine to form reactant are called irreversible reaction.

Characteristics

(1). Product does not recombine to form reactants.

(2) They are supposed to complete.

(3) They proceed in one ways only.

2.       Define chemical equilibrium state?

 When the rate of forward reaction takes place at the rate of reverse reaction, the composition of the reaction mixture remains constant; it is called chemical equilibrium state.

3.       Give the characteristics of reversible reaction?

Characteristics

(1) Products recombine to form reactants.

(2) They never complete.

(3) They proceed in both ways.

(4) They have double arrow between reactants and products.

4.       How is dynamic equilibrium established?

 Equilibrium established when reaction does not stop, only the rate of forward and reverse reactions become equal to each other but take place in opposite direction.

5.       Why at equilibrium state reaction does not stop?

 At equilibrium state reaction does not stop because reactants and products continue to react.

6.       Why at equilibrium state attainable from either way?

 An equilibrium state is attainable from either way starting from reactants or products.

7.       What is relationship between active mass and rate of reaction?

 Rate of a reaction is directly proportional to the product of the active masses of the reacting substances.

8.       Derive equilibrium constant expression for the synthesis of ammonia from nitrogen and hydrogen?

9.       Write the equilibrium constant expression for the following reactions:

H₂  +    I₂   ⇌   2HI

               

CO  +  3H₂  ⇌  CH₄   +   H₂O

                       

10.   How direction of a reaction can be predicted?

 Direction of a reaction at a particular moment can be predicted by inserting the concentration of the reactant and products at that particular moment in the equilibrium expression.

11.   How can we know that reaction has achieved an equilibrium state?

 if Q_c=K_c forward and reverse reactions take place at equal rates then equilibrium has been achieved.

12.   What are the characteristics of a reaction that established equilibrium state at once?

  Characteristics

(1).they has large numerical value.

(2).the reaction has almost gone to completion.

(3).the reaction mixture consists of almost all products and reactants are negligible.

13.   If reaction quotient Q_c of a reaction is more than K_c. what will be the direction of the reaction?

if Q_c>K_c; the reaction goes from right to left.

Exercise Multiple Choice Questions answers

1	A	6	A	11	D
2	C	7	D	12	B
3	D	8	C	13	C
4	D	9	C
5	D	10	A

Complete book chapter wise notes in pdf format can be downloaded from table given below,

Chapter No.	Chapter Title
Chapter    9	CHEMICAL EQUILIBRIUM	Download
Chapter   10	ACIDS, BASES AND SALTS	Download
Chapter 11	ORGANIC CHEMISTRY	Download
Chapter  12	HYDROCARBONS	Download
Chapter 13	BIOCHEMISTRY	Download
Chapter  14	THE ATMOSPHERE	Download
Chapter  15	WATER	Download
Chapter   16	CHEMICAL INDUSTRIES	Download