Physical and Chemical Equilibrium One Mark Questions

11th Standard

Reg.No. :
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Chemistry

Time : 00:30:00 Hrs
Total Marks : 10
10 x 1 = 10
1. If Kb and Kf for a reversible reactions are 0.8 ×10–5 and 1.6 × 10–4 respectively, the value of the equilibrium constant is,

(a)

20

(b)

0.2 x 10-4

(c)

0.05

(d)

none of these

2. The equilibrium constant for a reaction at room temperature is K1 and that at 700 K is K2. If K1 > K2, then

(a)

The forward reaction is exothermic

(b)

The forward reaction is endothermic

(c)

The reaction does not attain equilibrium

(d)

The reverse reaction is exothermic

3. Solubility of carbon dioxide gas in cold water can be increased by

(a)

increase in pressure

(b)

decrease in pressure

(c)

increase in volume

(d)

none of these

4. For which of the following reaction, the degree 0 dissociation (a) and equilibrium constant (Kp) are related as ${ K }_{ p }=\cfrac { 4\alpha ^{ 2 }P }{ \left( 1-{ \alpha }^{ }2 \right) } ?$

(a)

${ N }_{ 2 }{ O }_{ 4\left( g \right) }\rightleftharpoons 2{ NO }_{ 2 }\left( g \right)$

(b)

${ H }_{ 2\left( g \right) }+{ I }_{ 2\left( g \right) }\rightleftharpoons 2HI\left( g \right)$

(c)

$N_{ 2\left( g \right) }+{ 3H }_{ 2\left( g \right) }\rightleftharpoons 2NH_{ 3\left( g \right) }$

(d)

$PCI_{ 3\left( g \right) }Cl_{ 2\left( g \right) }\rightleftharpoons { PCI }_{ 5\left( g \right) }$

5. In which of the following does the reaction go almost to completion?

(a)

Kc = 103

(b)

Kc = 102

(c)

Kc = 10-2

(d)

Kc= 10-3

6. Hydrogen (a moles) and iodine (b moles) .react to give 2x moles of the HI at equilibrium. The total number of moles at equilibrium is

(a)

a+b+2x

(b)

(a-b)+(6-2x)

(c)

(a+b)

(d)

a+b-x

7. $A+B\rightleftharpoons C+D,{ k }_{ c }$for this reaction is 10. If c 1, 2, 3, 4 mole/litre of A, B, C and D respectively are present in a container at 25°C, the direction of reaction will be

(a)

From left to right

(b)

From right to left

(c)

Reaction is at equilibrium

(d)

Unpredictable

8. 4g H2' 32g 02' 14g N2 and 11g CO2 are taken ina bulb of 500ml. Which one of these has maximum active mass?

(a)

H2

(b)

O2

(c)

N2

(d)

CO2

9. For reaction, $2A+B\rightleftharpoons 2C,\quad K=x$ . Equilibrium constant for $C\rightleftharpoons A+1/2B$ will be

(a)

x

(b)

$\cfrac { x }{ 2 }$

(c)

$\cfrac { 1 }{ \sqrt { x } }$

(d)

$\sqrt { x }$

10. XY2 dissociates as,$XY_{ 2\left( g \right) }\rightleftharpoons { XY }_{ \left( g \right) }+Y_{ \left( g \right) }$ Initial pressure of XY2 is 600mm Hg. The total pressure at equilibrium is 800mm Hg. Assuming volume of system to remain constant, the value of Kp is

(a)

50

(b)

100

(c)

400

(d)

20