NTSE Chemistry Chemical Equilibrium MCQs

Question: Rate of an endothermic chemical reaction increases on -

• a) Decreasing the concentration of reactant
• b) Decreasing the surface area
• c) Decreasing the temperature
• d) None of these

Answer: Decreasing the temperature

Question: The function of an enzyme is a reaction of the type,

• a) Equilibrium constant
• b) Rate of forward reaction
• c) Rate of reverse reaction
• d) Activation energy.

Answer: Rate of reverse reaction

Question: Catalysts are those substance which -

• a) Only increase the rate of reaction
• b) Only decrease the rate of reaction
• c) Either increase or decrease the rate of reaction
• d) None of the above

Answer: None of the above

Question: Which of the following will react fastest ?

• a) Aluminum foil + NaOH + heat
• b) Aluminum foil + NaOH
• c) Aluminum powder + NaOH
• d) All will react equally

Answer: All will react equally

Question: What is the value of equilibrium constant K for the reaction

• a) K = 10^-14   
• b)  K = 1
• c) K = 1.8 × 10^-16
• d) K = 0

Answer: K = 10^-14   

Question: According to the law of mass action, the rate of reaction is directly proportional to the -

• a) Equilibrium constant
• b) Molar concentration of reactant (s)
• c) Volume
• d) Nature of reactant(s).

Answer: Molar concentration of reactant (s)

Question: During the process of photosynthesis, the product is -

• a) Sunlight
• b) Chlorophyll
• c) Carbon dioxide
• d) Glucose

Answer: Glucose

Question: Which of the following statements is incorrect ?

• a) In a multi step reaction, the rate determining step is the slowest one
• b) The specific rate constant for a reaction is independent of reactant concentration
• c) The rate of catalyzed reaction is always dependent on the concentration of the catalyst.
• d) The rise in temperature changes the specific rate constant of a reaction.

Answer: The rate of catalyzed reaction is always dependent on the concentration of the catalyst.

Question: Which of the following reactions will produce CO2 gas at the fasters rate ?       

• a) 10 g Na2 CO3 with 20 ml of 2 M H2SO4 
• b) 5 g Na2CO3 with 10 ml of 1 m H2SO4
• c) 5 g Na2CO3 with 10 ml of 2 M H2SO4  
• d) Both (B) & (C) have same rate of production of CO2

Answer: 10 g Na2 CO3 with 20 ml of 2 M H2SO4 

Question: Which of the following does not alter the concentration of the reactants and products are equilibrium ?

• a) Temperature
• b) Concentration
• c) Pressure
• d) Catalyst

Answer: Catalyst

More Questions...................

Question: If k_p < k_c then -

• a) n = 0
• b) n = + ve
• c) n= - ve   
• d) Cannot determine

Answer: n= - ve   

Question: Which of the following statements is correct about the equilibrium constant ?

• a) Its value increases by increase in temperature
• b) Its value decreases by decrease in temperature
• c) Its value may increase or decrease with increase in temperature
• d) Its value is constant at all temperatures

Answer: Its value may increase or decrease with increase in temperature

Question: When pressure is applied to the equilibrium system, Which of the following phenomenon will occur ?

• a) More ice will be formed
• b) Water will be evaporated
• c) More water will be formed
• d) Equilibrium will not be disturbed

Answer: More water will be formed

Question: At a given temperature, if there is a shift in equilibrium. The value of equilibrium constant will :

• a) Increase
• b) Decrease
• c) Remain constant
• d) May increase or decrease

Answer: Remain constant

Question: The oxidation of SO2 b O2 to SO3 is an exothermic reaction. The yield of SO3 will be maximum if

• a) Temperature in increased and pressure is kept constant
• b) Temperature is reduced and pressure is increased
• c) Both temperature and pressure and increased
• d) Both temperature and pressure and decreased

Answer: Temperature is reduced and pressure is increased

Question: The rate of forward reaction is two times that of the reverse reaction at a given temperature and identical concentration, K equilibrium is

• a) 0.5
• b) 1.5
• c) 2.5
• d) 2.0

Answer: 2.0

Question: In which of the following equilibrium, change in the volume of the system does not alter the number of moles.

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: For the reaction -

the rate may be expressed as :

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: Consider the reaction -

In occurs in one step. The specific rate constants for the forward and the reverse reactions are 2.5 × 10^-2 and 5 × 10^-3 respectively. The equilibrium constant is :           

• a) 1.25 × 102
• b) 5.0 × 10^-6 
• c) 2 × 105 
• d)  0.05 + 102

Answer:  0.05 + 102

Question: In the reaction,

  relation between K_P and K_C will be-        

• a) K_P = K_C 
• b) K_P > K_C  
• c) K_P < K_C 
• d)  Cannot predict

Answer: K_P = K_C 

Question: For a reversible reaction, - 

expression for K_C will be-

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: For a reaction

The following data is given at any time at 298 K

 [P] = 1 M, [Q] = 1 M, [R] = 1 M, [S] = 1 M.

the value of equilibrium constant K_c is 5. In which direction should the reaction proceed to attain equilibrium?

• a) Towards left hand side
• b) Towards right hand side
• c) The reaction will proceed at the same rate on both the sides
• d) The reaction will stop.

Answer: The reaction will proceed at the same rate on both the sides

Question: The following reaction was carried out in water

CI2 + 2I→I2 + 2CI-

The initial concentration of I- was 0.25 mol L^-1 and the concentration after 10 minutes was 0.23 mol L^-1 The rate of disappearance of I- and appearance of I2 is respectively -

• a) 0.002, 0.001 Mol L^-1 min^-1     
• b) 0.001, 0.002 Mol L^-1 min^-1
• c) 0.002, 0.002 Mol L^-1 min^-1      
• d) None of these

Answer: 0.001, 0.002 Mol L^-1 min^-1

Question: For following chemical reaction

KJ/mol. What would happen if the volume of the reaction vessel is doubled suddenly ?

• a) Unpredictable
• b) The equilibrium proceeds in the right direction.
• c) The equilibrium proceeds in the left direction
• d) Volume change doesn’t have any effect on equilibrium.

Answer: The equilibrium proceeds in the left direction

Question: The oxidation of SO2 b O2 to SO3 is an exothermic reaction. The yield of SO3 will be maximum if

• a) Temperature in increased and pressure is kept constant
• b) Temperature is reduced and pressure is increased
• c) Both temperature and pressure and increased
• d) Both temperature and pressure and decreased

Answer: Temperature is reduced and pressure is increased

Question: The reaction between Cr2O2 --- and HNO2 in an acidic medium is- 

Cr2O2--+ 5H+ + 3HNO2 → 2Cr⁺⁺⁺ + 3nO3- + 4H2O

The rate of disappearance of Cr2O7-- is found to be 2.4 × 10^-4 Mol L^-1 sec^-1 during a measured time interval, the rate of disappearance of HNO2 will be-

• a) 4.8 × 10^-4 Mol L^-1 sec^-1        
• b) 3 × 2.4 × 10^-4 Mol L^-1 sec^-1
• c) 7.2 × 10^-4 Mol L^-1 sec^-1  
• d) (B) & (C)

Answer: 4.8 × 10^-4 Mol L^-1 sec^-1                            

Question: Consider the following equilibrium in a closed container :

 At a fixed temperature, the volume of the reaction container is halved. For this change which of the following statements holds true regarding the equilibrium constant (K_p) and degree of  dissociation  (α)

• a) Neither K_p and  α nor changes 
• b) Both K_p and α change
• c) K_p changes, but α does not change 
• d) K_p does not change, but α changes

Answer: K_p does not change, but α changes

Question: At constant temperature, the equilibrium constant (K_p) for the decomposition reaction

  is expressed by K_p = 4x2P/(1 - x2) where P is pressure, x in extent of decomposition. Which of the following statement is true ?

• a) K_p increases with increase of P                
• b) K_p increases with increase of x
• c) K_p increases with decrease of x 
• d) K_p remains constant with change is P or x

Answer: K_p remains constant with change is P or x

Question: For the reversible reaction

at 5000 C. The value of K_p is 1.44 × 10^-5 when partial pressure is measured in atmospheres. The corresponding value of K_c with concentration is mol L^-1 is-

• a) 1.44 × 10^-5/(0.082 × 500) ^-5    
• b) 1.44 × 10^-5/(8.314 × 773) ^-2
• c) 1.44 × 10^-5/(0.082 × 500)2   
• d) 1.44 × 10^-5/(0.082 × 773) ^-2

Answer: 1.44 × 10^-5/(0.082 × 773) ^-2

Question: For the chemical reaction

   the amount of X3 Y at equilibrium is affected by

• a) Temperature and pressure
• b) Temperature only
• c) Pressure only
• d) Temperature, pressure and catalyst.

Answer: Temperature and pressure

Question: The oxidation of SO2 b O2 to SO3 is an exothermic reaction. The yield of SO3 will be maximum if 

• a) Temperature in increased and pressure is kept constant
• b) Temperature is reduced and pressure is increased
• c) Both temperature and pressure and increased
• d) Both temperature and pressure and decreased

Answer: Temperature is reduced and pressure is increased

Question: The equilibrium constant for the following reaction will be- 3 A + 2B →C

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: The rate of forward reaction is two times that of the reverse reaction at a given temperature and identical concentration, K equilibrium is

• a) 0.5
• b) 1.5
• c) 2.5
• d) 2.0

Answer: 2.0

Question: When H2 and I2 are mixed and equilibrium is attained, then    

• a) Amount of HI formed is equal to the amount of H2 dissociated
• b) HI dissociation stops
• c) The reaction stops completely
• d) None of these

Answer: None of these

Question: In which of the following equilibrium, change in the volume of the system does not alter the number of moles.

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question: If K2 and K2 are the equilibrium constants of the equilibrium (a) and (b) respectively, what is the relationship between the two constants ?

• a)

  

• b)

  K₂ = (K₁)²

• c)

  

• d)

  K₁ = K₂.

Answer:

Question: At a given temperature, the equilibrium constant for the reactions

  and   are K2 and K2 respectively. If K2 si 4 × 10^-3 then K2 will be

• a) 8 × 10^-3     
• b) 16 × 10^-3
• c) 6.25 × 104         
• d)  6.25 × 106

Answer: 6.25 × 104         

Question: If K_p for a reaction

is 0.05 atm at 1000 K. Its K_c in terms of R will be

• a) 20000 R
• b) 0.02 R
• c) 5 × 10^-5 R    
• d)

  

Answer:

Question: Consider the reaction

in closed container at equilibrium. What would be the effect of additions of CaCO3 on the equilibrium concentration of CO2 ?

• a) Increases
• b) Decreases
• c) Data is not sufficient to predict it
• d) Remains unaffected

Answer: Remains unaffected

Question: For the redox reaction MnO4- + C2O4^2- + H+ → Mn²⁺ + CO2 + H2O  the correct coefficients of the reactants for the balanced reaction are - 

       MnO4-                 C2O4^2-               H+                

• a) 2                      5                      16
• b) 16                     5                      2        
• c) 5                      16                     2
• d) 2                      16                     5

Answer: 2                      5                      16

Question: In termite process, the reducing agent is -

• a) C
• b) Zn
• c) Na
• d) AI

Answer: AI

Question: Lead nitrate on heating gives lead oxide, nitrogen dioxide and oxygen. The reaction is known as -

• a) Decomposition
• b) Combustion
• c) Displacement
• d) Combination

Answer: Decomposition

Question: Rusting of iron is a chemical reaction. The reaction can be termed as -

• a) Displacement
• b) Oxidation
• c) Double decomposition
• d) Substitution

Answer: Oxidation

Question: The reaction, Na2SO4 + BaCI2 →BaSO4 + NaCI is -

• a) Decomposition
• b) Double displacement
• c) Substitution
• d) Combination

Answer: Double displacement

Question: When H2 and I2 are mixed and equilibrium is attained, then

• a) Amount of HI formed is equal to the amount of H2 dissociated
• b) HI dissociation stops
• c) The reaction stops completely
• d) None of these

Answer: None of these