# Chemical Equilibrium Test 1

Total Questions:50 Total Time: 75 Min

Remaining:

## Questions 1 of 50

Question:A reaction attains equilibrium when the free energy change accompanying it is

Positive and large

Zero

Negative and large

Negative and small

## Questions 2 of 50

Question:$$\Delta {G^0}(HI,\,g) \cong + 1.7\,kJ$$. What is the equilibrium constant at $${25^o}C$$ for $$2HI(g)$$ $$\Leftrightarrow$$ $${H_2}(g) + {I_2}(g)$$

24

3.9

2

0.5

## Questions 3 of 50

Question:The standard state gibbs free energy change for the given isomerization reaction cis-2-pentene $$\Leftrightarrow$$ trans –2 -pentene is $$- 3.67\,kJ/mol$$ at $$400K$$. If more trans-2-pentene is added to the reaction vessel, then

More cis –2–pentene is formed

Equilibrium is shifted in the forward direction

Equilibrium remains unaffected

## Questions 4 of 50

Question:In a reversible reaction, the catalyst­­

Increases the activation energy of the backward reaction

Increases the activation energy of the forward reaction

Decreases the activation energy of both, forward and backward reaction

Decreases the activation energy of forward reaction

## Questions 5 of 50

Question:In which of the following reaction, the value of $${K_p}$$ will be equal to $${K_c}$$

$${H_2} + {I_2}$$ $$\Leftrightarrow$$ $$2HI$$

$$PC{l_5}$$ $$\Leftrightarrow$$ $$PC{l_3} + C{l_2}$$

$$2N{H_3}$$ $$\Leftrightarrow$$ $${N_2} + 3{H_2}$$

$$2S{O_2} + {O_2}$$ $$\Leftrightarrow$$$$2S{O_3}$$

## Questions 6 of 50

Question:Equilibrium constants $${K_1}$$and $${K_2}$$for the following equilibria $$NO(g) + \frac{1}{2}{O_2}$$ $$N{O_2}(g)$$ and $$2N{O_2}(g)$$ $$2NO(g) + {O_2}(g)$$ are related as

$${K_2} = \frac{1}{{{K_1}}}$$

$${K_2} = K_1^2$$

$${K_2} = \frac{{{K_1}}}{2}$$

$${K_2} = \frac{1}{{K_1^2}}$$

## Questions 7 of 50

Question:For the reaction $$PC{l_3}(g) + C{l_2}(g)$$ $$\Leftrightarrow$$ $$PC{l_5}(g)$$ at $${250^o}C$$, the value of $${K_c}$$ is 26, then the value of $${K_p}$$ on the same temperature will be

0.61

0.57

0.83

0.46

## Questions 8 of 50

Question:The relation between equilibrium constant $${K_p}$$ and $${K_c}$$ is

$${K_c} = {K_p}\,{(RT)^{\Delta n}}$$

$${K_p} = {K_c}{(RT)^{\Delta n}}$$

$${K_p} = {\left( {\frac{{{K_c}}}{{RT}}} \right)^{\Delta n}}$$

$${K_p} - {K_c} = {(RT)^{\Delta n}}$$

## Questions 9 of 50

Question:For the reaction $${H_2}(g) + {I_2}(g)$$ $$\Leftrightarrow$$ $$2HI(g)$$ at $$721K$$ the value of equilibrium constant $$({K_c})$$ is 50. When the equilibrium concentration of both is $$0.5\,M$$, the value of $${K_p}$$ under the same conditions will be

0.002

0.2

50

$$50/RT$$

## Questions 10 of 50

Question:In which of the following reaction $${K_p} > {K_c}$$

$${N_2} + 3{H_2}$$ $$\Leftrightarrow$$ $$2N{H_3}$$

$${H_2} + {I_2}$$ $$\Leftrightarrow$$$$2HI$$

$$PC{l_3} + C{l_2}$$ $$\Leftrightarrow$$ $$PC{l_5}$$

$$2S{O_3}$$ $$\Leftrightarrow$$$${O_2} + 2S{O_2}$$

## Questions 11 of 50

Question:For the reaction $$PC{l_5}(g)$$ \ [ \Leftrightarrow \) $$PC{l_3}(g) + C{l_2}(g)$$

$${K_p} = {K_c}$$

$${K_p} = {K_c}{(RT)^{ - 1}}$$

$${K_p} = {K_c}(RT)$$

$${K_p} = {K_c}{(RT)^2}$$

## Questions 12 of 50

Question:The equilibrium constant of the reaction $${H_2}(g) + {I_2}(g)$$ $$\Leftrightarrow$$ $$2HI(g)$$ is 64. If the volume of the container is reduced to one fourth of its original volume, the value of the equilibrium constant will be

16

32

64

128

## Questions 13 of 50

Question:The reaction between $${N_2}$$ and $${H_2}$$ to form ammonia has $${K_c} = 6 \times {10^{ - 2}}$$ at the temperature 500°C. The numerical value of $${K_p}$$ for this reaction is

$$1.5 \times {10^{ - 5}}$$

$$1.5 \times {10^5}$$

$$1.5 \times {10^{ - 6}}$$

$$1.5 \times {10^6}$$

## Questions 14 of 50

Question:For the gaseous phase reaction 2NO $$\Leftrightarrow$$ $${N_2} + {O_2}\,\,\,\,\Delta H^\circ = + \;43.5\,\,kcal\,mo{l^{ - 1}}$$ Which statement is correct

K varies with addition of NO

K decrease as temperature decreases

K Increases as temperature decreases

K is independent of temperature

## Questions 15 of 50

Question:For the reversible reaction,$${N_{2(g)}} + 3{H_{2(g)}}$$ $$\Leftrightarrow$$$$2N{H_{3(g)}}$$at 500°C, the value of $${K_P}$$ is $$1.44 \times {10^{ - 5}}$$ when partial pressure is measured in atmospheres. The corresponding value of $${K_c}$$ with concentration in mole litre-1, is

$$1.44 \times {10^{ - 5}}$$/$${\left( {0.082 \times 500} \right)^{ - 2}}$$

$$1.44 \times {10^{ - 5}}$$/$${\left( {8.314 \times 773} \right)^{ - 2}}$$

$$1.44 \times {10^{ - 5}}$$/$${\left( {0.082 \times 773} \right)^2}$$

$$1.44 \times {10^{ - 5}}$$/$${\left( {0.082 \times 773} \right)^{ - 2}}$$

## Questions 16 of 50

Question:A chemical reaction is catalyzed by a catalyst X. Hence X

Reduces enthalpy of the reaction

Decreases rate constant of the reaction

Increases activation energy of the reaction

Does not affect equilibrium constant of reaction

## Questions 17 of 50

Question:$$\Delta n$$, the change in the number of moles for the reaction, $${C_{12}}{H_{22}}{O_{11}}_{(s)}$$$$+ 12{O_{2(g)}}$$ $$\Leftrightarrow$$$$12C{O_{2(g)}}$$ $$+ 11{H_2}{O_{(l)}}$$at 25°C is

0

2

4

1

## Questions 18 of 50

Question:Value of $${K_p}$$in the reaction $$MgC{O_{3(s)}}$$ $$\Leftrightarrow$$$$Mg{O_{(s)}}$$ $$+ \,C{O_{2(g)}}$$ is

$${K_P} = {P_{CO}}_2$$

$${K_P} = Pc{o_2} \times \frac{{Pc{o_2} \times {P_{MgO}}}}{{{P_{MgC{O_3}}}}}$$

$$K{}_P = \frac{{Pc{o_2} \times {P_{MgO}}}}{{{P_{MgC{O_3}}}}}$$

$${K_P} = \frac{{{P_{MgC{O_3}}}}}{{{P_{C{O_2}}} \times {P_{MgO}}}}$$

## Questions 19 of 50

Question:For $${N_2} + 3{H_2}$$ $$\Leftrightarrow$$$$2N{H_3}$$ equilibrium constant is k then equilibrium constant for 2N2 + 6H2 $$\Leftrightarrow$$ 4NH3 is

$$\sqrt k$$

$${k^2}$$

$$k/2$$

$$\sqrt {k\; + \;1}$$

## Questions 20 of 50

Question:For the following reaction in gaseous phase $$CO + \frac{1}{2}{O_2} \to C{O_2}$$; $${K_p}/{K_c}$$ is

$${(RT)^{1/2}}$$

$${(RT)^{ - 1/2}}$$

$$(RT)$$

$${(RT)^{ - 1}}$$

## Questions 21 of 50

Question:For the reaction $${N_{2(g)}} + {O_{2(g)}}$$ $$\Leftrightarrow$$$$2N{O_{(g)}}$$, the value of $${K_c}$$ at $${800^o}C$$ is 0.1. When the equilibrium concentrations of both the reactants is 0.5 mol, what is the value of $${K_p}$$ at the same temperature

0.5

0.1

0.01

0.025

## Questions 22 of 50

Question:$${A_{(g)}} + 3{B_{(g)}}$$ $$\Leftrightarrow$$$$4{C_{(g)}}$$. Starting concentration of A is equal to B, equilibrium concentration of A and C are same. $${K_c} =$$

0.08

0.8

8

80

1/8

## Questions 23 of 50

Question:2 moles of $$PC{l_5}$$ were heated in a closed vessel of 2 litre capacity. At equilibrium, 40% of $$PC{l_5}$$ is dissociated into $$PC{l_3}$$ and $$C{l_2}$$. The value of equilibrium constant is

0.266

0.53

2.66

5.3

## Questions 24 of 50

Question:For which of the following reactions does the equilibrium constant depend on the units of concentration

$$N{O_{(g)}}$$ \

[ \Leftrightarrow \) $$\frac{1}{2}{N_{2(g)}} + \frac{1}{2}{O_{2(g)}}$$

$$Z{n_{(s)}} + Cu_{(aq)}^{2 + }$$ \

[ \Leftrightarrow \) $$C{u_{(s)}} + Zn_{(aq)}^{2 + }$$

## Questions 25 of 50

Question:$${C_2}{H_5}O{H_{(l)}} + C{H_3}COO{H_{(l)}}$$ $$\Leftrightarrow$$$$C{H_3}COO{C_2}{H_{5(l)}} + {H_2}{O_{(l)}}$$ (Reaction carried in an inert solvent) $$COC{l_{2(g)}}$$ $$\Leftrightarrow$$ $$C{O_{(g)}} + C{l_{2\,(g)}}$$ Unit of equilibrium constant for the reversible reaction $${H_2} + {I_2}$$ $$\Leftrightarrow$$ $$2HI$$ is

$$mo{l^{ - 1}}\,litre$$

$$mo{l^{ - 2}}\,litre$$

$$mol\,\,litr{e^{ - 1}}$$

None of these

## Questions 26 of 50

Question:In a chemical equilibrium, the rate constant of the backward reaction is $$7.5 \times {10^{ - 4}}$$ and the equilibrium constant is 1.5. So the rate constant of the forward reaction is

$$5 \times {10^{ - 4}}$$

$$2 \times {10^{ - 3}}$$

$$1.125 \times {10^{ - 3}}$$

$$9.0 \times {10^{ - 4}}$$

## Questions 27 of 50

Question:28 g of $${N_2}$$ and 6 g of $${H_2}$$ were kept at $${400^o}C$$ in 1 litre vessel, the equilibrium mixture contained $$27.54g$$ of $$N{H_3}$$. The approximate value of $${K_c}$$ for the above reaction can be (in $$mol{e^{ - 2}}\,\,litr{e^2}$$)

75

50

25

100

## Questions 28 of 50

Question:The equilibrium concentration of $$X,\,Y$$ and $$Y{X_2}$$ are 4, 2 and 2 moles respectively for the equilibrium $$2X + Y$$ $$\Leftrightarrow$$$$Y{X_2}$$. The value of $${K_c}$$ is

0.625

0.0625

6.25

0.00625

## Questions 29 of 50

Question:In the reaction, $$A + B$$ $$\Leftrightarrow$$$$2C$$, at equilibrium, the concentration of A and B is $$0.20\,\,mol\,\,{l^{ - 1}}$$ each and that of C was found to be $$0.60\,\,mol\,\,{l^{ - 1}}$$. The equilibrium constant of the reaction is

2.4

18

4.8

9

## Questions 30 of 50

Question:15 moles of $${H_2}$$ and 5.2 moles of $${I_2}$$ are mixed and allowed to attain equilibrium at $${500^o}C$$. At equilibrium, the concentration of $$HI$$ is found to be 10 moles. The equilbrium constant for the formation of $$HI$$ is

50

15

100

25

## Questions 31 of 50

Question:In a chemical reaction equilibrium is established when

Opposing reaction ceases

Concentration of reactants and products are equal

Velocity of opposing reaction is the same as that of forward reaction

Reaction ceases to generate heat

## Questions 32 of 50

Question:The reaction, $$2S{O_{2(g)}} + {O_{2(g)}}$$ $$\Leftrightarrow$$ $$2S{O_{3(g)}}$$ is carried out in a 1$$d{m^3}$$vessel and $$2\;d{m^3}$$vessel separately. The ratio of the reaction velocities will be

$$1:8$$

$$1:4$$

$$4:1$$

$$8:1$$

## Questions 33 of 50

Question:The compound A and B are mixed in equimolar proportion to form the products, $$A + B$$ $$\Leftrightarrow$$ $$C + D$$. At equilibrium, one third of A and B are consumed. The equilibrium constant for the reaction is

0.5

4

2.5

0.25

## Questions 34 of 50

Question:Calculate the partial pressure of carbon monoxide from the following ; $${K_p} = 8 \times {10^{ - 2}}$$$$C{O_{2(g)}} + {C_{(s)}} \to 2C{O_{(g)}}$$ ; $${K_p} = 2$$

0.2

0.4

1.6

4

## Questions 35 of 50

Question:The active mass of 64 gm of HI in a two litre flask would be

2

1

5

0.25

## Questions 36 of 50

Question:Under a given set of experimental conditions, with increase in the concentration of the reactants, the rate of a chemical reaction

Decreases

Increases

Remains unaltered

First decreases and then increases

## Questions 37 of 50

Question:The law of mass action was enunciated by

Guldberg and Waage

Bodenstein

Birthelot

Graham

## Questions 38 of 50

Question:On the velocity in a reversible reaction, the correct explanation of the effect of catalyst is

It provides a new reaction path of low activation energy

It increases the kinetic energy of reacting molecules

It displaces the equilibrium state on right side

It decreases the velocity of backward reaction

## Questions 39 of 50

Question:Select the correct statement from the following

Equilibrium constant changes with addition of catalyst

Catalyst increases the rate of forward reaction

The ratio of mixture at equilibrium is not changed by catalyst

Catalyst are active only in solution

## Questions 40 of 50

Question:According to Le-chatelier principle, if heat is given to solid-liquid system, then

Quantity of solid will reduce

Quantity of liquid will reduce

Increase in temperature

Decrease in temperature

## Questions 41 of 50

Question:The endothermic reaction $$(M + N$$ $$\Leftrightarrow$$$$P)$$ is allowed to attain an equilibrium at $${25^o}$$. Formation of $$P$$ can be increased by

Raising temperature

Lowering temperature

Keeping temperature constant

Decreasing the concentration of $$M$$ and $$N$$

## Questions 42 of 50

Question:According to Le-chatelier's principle, an increase in the temperature of the following reaction will$${N_2} + {O_2}$$ $$\Leftrightarrow$$$$2NO - 43,200\,kcal$$

Increase the yield of $$NO$$

Decrease the yield of $$NO$$

Not effect the yield of $$NO$$

Not help the reaction to proceed in forward direction

## Questions 43 of 50

Question:In the manufacture of $$N{H_3}$$ by Haber's process, the condition which would give maximum yield is $${N_2} + 3{H_2}$$ $$\Leftrightarrow$$ $$2N{H_3} + Q\,kcal$$

High temperature, high pressure and high concentrations of the reactants

High temperature, low pressure and low concentrations of the reactants

Low temperature and high pressure

Low temperature, low pressure and low concentration of $${H_2}$$

## Questions 44 of 50

Question:In $${N_2} + 3{H_2}$$ $$\Leftrightarrow$$$$2N{H_3}$$ reversible reaction, increase in pressure will favour

Reaction in forward direction

Reaction in reverse direction

Will not exert any effect

In backward and forward direction equally

## Questions 45 of 50

Question:In the reaction $${N_2} + 3{H_2} \to 2N{H_3}$$, the product increases on

Increasing temperature

Increasing pressure

Increasing temperature and pressure both

Decreasing temperature and pressure both

None of these

## Questions 46 of 50

Question:In which of the following system, doubling the volume of the container cause a shift to the right

$${H_2}(g) + C{l_2}(g) = 2HCl(g)$$

$$2CO(g) + {O_2}(g) = 2C{O_2}(g)$$

$${N_2}(g) + 3{H_2}(g) = 2N{H_3}(g)$$

$$PC{l_5}(g)$$ $$\Leftrightarrow$$$$PC{l_3}(g) + C{l_2}(g)$$

## Questions 47 of 50

Question:On addition of an inert gas at constant volume to the reaction $${N_2} + 3{H_2}$$ $$\Leftrightarrow$$$$2N{H_3}$$at equilibrium

The reaction remains unaffected

Forward reaction is favoured

The reaction halts

Backward reaction is favoured

## Questions 48 of 50

Question:Le-Chatelier principle is not applicable to

$${H_{2(g)}} + {I_{2(g)}}$$ $$\Leftrightarrow$$$$2H{I_{(g)}}$$

$$F{e_{(S)}} + {S_{(S)}}$$ $$\Leftrightarrow$$$$Fe{S_{(S)}}$$

$${N_{2(g)}} + 3{H_{2(g)}}$$ $$\Leftrightarrow$$$$2N{H_{3(g)}}$$

$${N_{2(g)}} + {O_{2(g)}}$$ $$\Leftrightarrow$$$$2N{O_{(g)}}$$

## Questions 49 of 50

Question:For the reaction: A + B + Q $$\Leftrightarrow$$ C + D, if the temperature is increased, then concentration of the products will

Increase

Decrease

Remain same

Become Zero

## Questions 50 of 50

Question:Consider the reaction equilibrium, $$2S{O_{2(g)}}$$+$${O_{2(g)}}$$ $$\Leftrightarrow$$$$2S{O_{3(g)}}$$; $$\Delta H^\circ$$= –198kJ. On the basis of Le-Chatelier’s principle, the condition favourable for the forward reaction is