equilibrium-chemistry

EQUILIBRIUM 1.

2.

3.

4.

5.

6.

Under a given set of experimental conditions, with increase in the concentration of the reactants, the rate of a chemical reaction (a) Decreases (b) Increases (c) Remains unaltered (d) First decreases and then increases The law of mass action was enunciated by (a) Guldberg and Waage (b) Bodenstein (c) Birthelot (d) Graham Theory of ‘active mass’ indicates that the rate of chemical reaction is directly proportional to the (a) Equilibrium constant (b) Properties of reactants (c) Volume of apparatus (d) Concentration of reactants The rate at which substances react depends on their (a) Atomic weight (b) Molecular weight (c) Equivalent weight (d) Active mass Which is false (a) The greater the concentration of the substances involved in a reaction, the lower the speed of the reaction (b) The point of dynamic equilibrium is reached when the reaction rate in one direction just balances the reaction rate in the opposite direction (c) The dissociation of weak electrolyte is a reversible reaction (d) The presence of free ions facilitates chemical changes Chemical equations convey quantitative information on the (a) Type of atoms/molecules taking part in the reaction (b) Number of atoms/molecules of the reactants and products involved in the reaction (c) Relative number of moles of reactants and products involved in the reaction (d) Quantity of reactant consumed and quantity of product formed

7.

In the thermal decomposition of potassium chlorate given as 2 K ClO3 2 KCl 3O2 , law of mass action (a) Cannot be applied (b) Can be applied (c) Can be applied at low temperature (d) Can be applied at high temp. and pressure

8.

For the system 3A 2B ⇌ C , the expression for equilibrium constant is

[3A][ 2B] (a) C 9.

[C] (b) [3A][ 2B]

[ A ] 3 [ B] 2 (c) [C]

(d)

[C] [A]3 [B]2

In the reversible reaction A B ⇌ C D , the concentration of each C and D at equilibrium was 0.8 mole/litre, then the equilibrium constant K c will be (a) 6.4

(b) 0.64

(c) 1.6

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(d) 16.0

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10.

4 moles of A are mixed with 4 moles of B. At equilibrium for the reaction A moles of C and D are formed. The equilibrium constant for the reaction will be (a)

11.

12.

13.

14.

15.

1 4

(b)

1 2

(c) 1

B⇌C D, 2

(d) 4

On a given condition, the equilibrium concentration of HI, H 2 and I 2 are 0.80, 0.10 and 0.10 mole/litre. The equilibrium constant for the reaction H 2 I 2 ⇌ 2HI will be (a) 64 (b) 12 (c) 8 In which of the following, the reaction proceeds towards completion

(d) 0.8

(a) K 103 (b) K 10 2 (c) K 10 (d) K 1 A reversible chemical reaction having two reactants in equilibrium. If the concentrations of the reactants are doubled, then the equilibrium constant will (a) Also be doubled (b) Be halved (c) Become one-fourth (d) Remain the same The equilibrium constant in a reversible reaction at a given temperature (a) Depends on the initial concentration of the reactants (b) Depends on the concentration of the products at equilibrium (c) Does not depend on the initial concentrations (d) It is not characteristic of the reaction Pure ammonia is placed in a vessel at temperature where its dissociation constant ( ) is appreciable. At equilibrium (a) K p does not change significantly with pressure (b)

does not change with pressure

(c) Concentration of NH 3 does not change with pressure (d) Concentration of H 2 is less than that of N 2 16.

For the system A(g) 2B(g) ⇌ C(g) , the equilibrium concentrations are (A) 0.06 mole/litre (B) 0.12 mole/litre (C) 0.216 mole/litre. The K eq for the reaction is (a) 250

17.

(b) 416

(c) 4 10

The equilibrium constant for the given reaction H 2

3

(d) 125

I 2 ⇌ 2HI is correctly given by expression

(a) K c

[H 2 ][ I 2 ] [HI]

(b) K c

[H 2 ][ I 2 ] [2HI]

(c) K c

[H 2 ][ I 2 ] [HI]2

(d) K c

[HI]2 [H 2 ][ I 2 ]

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ANSWERS 1

b

2

a

3

d

4

d

5

a

6

c

7

a

8

d

9

d

10

c

11

a

12

a

13

d

14

c

15

a

16

a

17

d

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