Q.1
in the equilibrium reaction involving the dissociation of CaCO3(s) ↔ CaO(s) + CO2(s)the equilibrium constant is given by ...[Pb. CET 1991]
  • a)
    ch-8_qn-82choice_img_no1.png
  • b)
    ch-8_qn-82choice_img_no2.png
  • c)
    ch-8_qn-82choice_img_no3.png
  • d)
    ch-8_qn-82choice_img_no4.png
Q.2
The yield of the product in the reactionA2(g) + 2B(g) ↔ C(g) + Q kJ would be higher at [ MLNR 1988]
  • a) High temperature and high pressure
  • b) High temperature and low pressure
  • c)Low temperature and high pressure
  • d)Low temperature and low pressure
Q.3
The equilibrium constant for the reaction H2(g) + I2(g) ↔ 2HI9g) at a certain temperature isthen the equilibrium constant for the reaction HI9g) ↔ ½ H2(g) + ½I2(g) at the same temperature is ..[Pb. CET1990]
  • a) 7
  • b) 1/7
  • c) 24.5
  • d) 98
Q.4
A liquid is in equilibrium with its vapour at its boiling point. On the average, the molecules in the two phases have equal .. [ IIT 1984]
  • a)Intermolecular force
  • b) Potential energy
  • c)kinetic energy
  • d)both kinetic and potential energy
Q.5
Select the reaction for which the equilibrium constant is written as [MX3]2=K [ MX2]2[X2]
  • a) MX3 ↔ MX2 + ½ X2
  • b) 2MX3 → 2MX2 + X2
  • c)2MX2 + X2 ↔ 2MX3
  • d)MX2 + ½X2 ↔ MX3
Q.6
For which of the following systems at equilibrium at constant temperature, doubling the volume will cause a shift to the right? [ KCET 1992]
  • a) H2(g) + Cl2(g) ↔ 2HCl(g)
  • b) 2CO(g) + O2(g) ↔ 2CO2(g)
  • c) N2(g) + 3H2(g) ↔ 2NH3(g)
  • d) PCl5(g) ↔ PCl3 + Cl2(g)
Q.7
Which of the following will not change the concentration of ammonia in the equilibrium N2(g) + 3H2(g0 ↔ 2NH3(g); ΔH=-x kJ [ Pb. CET 1985]
  • a)Increase of pressure
  • b) Increase of temperature
  • c) Decrease of volume
  • d)Addition of catalyst
Q.8
The equilibrium N2 + O2 ↔ 2NO is established in reaction vessel of 2.5L capacity. the amount of N2 and O2 taken at the start were respectively 2 moles and 4moles. Half a mole of nitrogen has been used up at equilibrium. the molar concentration of nitric oxide is [ KCET 1985]
  • a) 0.2
  • b) 0.4
  • c)0.6
  • d)0.1
Q.9
In case of gaseous homogenous reaction, the active mass of the reactant is obtained by the expression ..[Tamil nadu CET 2002]
  • a) PV/RT
  • b) P/RT
  • c)RT/P
  • d)nRT/V
Q.10
For the reaction 2A + B ↔ C, ΔH=+x cals, which one of the following conditions would favour the yield of C on the basis of Le Chatelier principle? [ Harayana CEET 1991]
  • a) Higher pressure, higher temperature
  • b) Only low temperature
  • c)Higher pressure, low temperature
  • d)only low pressure
Q.11
At a certain temperature, the following reactions: NO(g) + ½O2(g) ↔ NO2() NO2(g) + NO(g) ↔ N2O3 (g) have equilibrium constant K1 and K2 respectively. The equilibrium constant for the reaction2NO(g) + ½O2(g) ↔ N2O3(g) at the same temperature would be ..[Pb CET sample paper 1993]
  • d) K1 K2
  • a) K₁ + K₂
  • b) K₁ / K₂
  • c) K₂ / K₁
Q.12
The effect of increasing the pressure on the following equilibrium 2A + 3B ↔ 3 A + 2B is ...[EAMCET 1980]
  • a)Forward reaction is favoured
  • b) Backward reaction is favoured
  • c)No effect
  • d)None of above
Q.13
In which of the following cases, does the reaction go farthest to completion? [ MLNR 1990]
  • a) K=102
  • b) K=10
  • c)K=10-2
  • d)K=1
Q.14
For the system A(g) + 2B(g) ↔ C(g), the equilibrium concentrations are A=0.06 mol/L, B=0.12 mol/L, C=0.216 mol/L The Keq for the reaction is ..[CPMT 1983]
  • a) 250
  • b) 416
  • c)4 × 10⁻³
  • d)125
Q.15
A chemical system is in equilibrium. Addition of catalyst would result in [ KCET 1993]
  • a) increase in the rate of forward reaction
  • b) increase in the rate of reverse reaction
  • c) a new reaction path
  • d) increase the amount of heat evolved in the reaction
Q.16
The equilibrium constant in a reversible chemical reaction at a given temperature .. [ AIIMS 1982]
  • a)depends on the initial concentration of the reactants
  • b) depends on the concentration of one of the products at equilibrium
  • c)does not depend on the initial concentration of reactants
  • d)is not characteristics of the reaction
Q.17
56g of N2 and 6g of H2 were kept at 400°C in 1 litre vessel. The equilibrium mixture contained 27.54g of NHthe approximate value for Ke for the above reaction in mol2/L is ...[CBSE PMT 1989]
  • a) 10
  • b) 20
  • c)30
  • d)40
Q.18
A and B are gaseous substances which react reversibly to give two gaseous substances C and D, accompanied by the liberation of heat. When the reaction reaches equilibrium, it is observed that Kp=Kc. the equilibrium can not be disturbed by [ KCET 1988]
  • a) Adding A
  • b) Adding D
  • c)Increasing pressure
  • d)Rising temperature
Q.19
In the gas phase reactionC2H4 + H2 ↔ C2H6the equilibrium constant can be expressed in units of ..[CBSE PMT 1992]
  • a) litre-1 mol-1
  • b) mol2 litre-2
  • c) litre mole-1
  • d) mole litre-1
Q.20
Pure ammonia is placed in vessel at temperature where its dissociation is appreciable. At equilibrium ..[IIT 1984]
  • a)Kp does not change significantly with pressure
  • b) α does not change with pressure
  • c)concentration of NH3 does not change with pressure
  • d)concentration of H2 is less than that of N2
Q.21
Two moles of HI were heated in a sealed tube at 440°C till the equilibrium was reached. HI was found to be 22% decomposed. the equilibrium constant for dissociation is [ AFMC 1994]
  • a) 0.282
  • b) 0.0796
  • c)0.0199
  • d)1.99
Q.22
For reaction at equilibrium, Le Chatelier's principle predicts the effects of ..[Bihar CEE 1992]
  • a) temperature and pressure
  • b) temperature and volume
  • c)pressure and volume
  • d)only volume
Q.23
K1 and K2 are equilibrium constant for reaction (1) and (2)N2(g) + O2(g) ↔ 2NO(g) ...(1)NO(g) ↔ ½ N2(g) + ½O2(g) ..(2)Then .. [CBSE PMT 1989]
  • b) K1=K22
  • c) K1K2=1
  • a) K₁=(1/K₂)²
  • d) K₁=(K₂)0
Q.24
k1 and k2 are the velocity constant of forward and backward reaction. The equilibrium constant K of the reaction is ..[KCET 1985]
  • d)none of above
  • a)k₁ × k₂
  • b) k₁ - k₂
  • c)k₁/k₂
Q.25
According to Le-Chatelier's principle, adding heat to a solid and liquid in equilibrium will cause the [ MLNR 1990]
  • a) temperature to increase
  • b) temperature to decrease
  • c)amount of liquid to decrease
  • d)amount of solid to decrease
Q.26
A cylinder filled with a movable piston contains liquid water in equilibrium with water vapour at 25°C. Which one of the following operations results in a decrease in the equilibrium vapour pressure? [ AIIMS 1993]
  • a) Moving the piston downward a short distance
  • b) removing a small amount of vapour
  • c) removing a small amount of the liquid water
  • d) Dissolving salt in water
Q.27
CH3COOH + C2H5OH ↔ CH3COOC2H5 + H2O In the above reaction one mole each of the acetic acid and alcohol are heated in the presence of little conc.H2SOOn equilibrium being attained [ CPMT 1985]
  • a)1 mole of ethyl acetate is formed
  • b) 2 moles of ethyl acetate are formed
  • c)1/3 mole of ethyl acetate is formed
  • d)unpredictable
Q.28
The active mass of 64g of HI in a two litre flask would be ..[CPMT 1979]
  • a) 2
  • b) 1
  • c)5
  • d)0.25
Q.29
In an exothermic reaction, a 10° rise in temperature will [ Bangalore PMT 1993]
  • a) decrease the value of equilibrium constant
  • b) double the value of Kc
  • c)not produce any change in Kc
  • d)produce some increase in Kc
Q.30
For the homogeneous reaction4NH3 + 5O2 ↔ 4NO + 6H2 the equilibrium constant Kc has the units of ..[CPMT 1990]
  • a) conc.+10
  • b) conc.+1
  • c) conc.-1
  • d) It is dimension less
0 h : 0 m : 1 s