ECAT Pre Engineering Chemistry Chapter 8 MCQ Test With Answer

pH of 1 molar NaOH is

• 7 A
• zero B
• 14 C
• 10 D

The ionization constant of an acid is expressed in term of the following constant

• Kw A
• Kn B
• Ka C
• Kb D

What happens when reaction is at equilibrium and more reactant is added :

• Forward reaction rate is increased. A
• Forward reaction rate is decreased. B
• Backward reaction rate is increased. C
• Equilibrium remains unchanged. D

H₂ + L₂ ----2Hl

In the above equilibrium system, if the concentration of reactants at 25°C is increased, the value K_C will :

• Remains Constant A
• Increases B
• Cecreases C
• Depends upon nature of reactans D

• Increases A
• Decreases B
• Remains same C
• Cannot be predicted D

Which of the following solution have zero pH

• 1 M HCI A
• MH₂SO₄ B
• 0.1 M HNO₃ C
• 1 M CH₃COOH D

The ph of 10-3 mole dm-3 of an aqueous solution of H₂SO₄ is :

• 3.0

  A

• 2.7

  B
• 2.0 C

• 1.5

  D

1 mol of N₂O₄ was decomposed according to given equation in 1dm₃ container. At equilibrium x mole of N₂O₄ have dissociated. What is the value of K_C:

• 2x/(1-x)²

  A

• 4x²/(1-x)

  B

• 4x/(1-x)

  C

• 2x/(1-x)

  D

The solubility product of AgCl is 2.0 x 10^-10mole ²dm^-6. The maximum concentration of Ag⁺ions in the solution is

• 2.0 x 10^-10mole dm^-3 A
• 1.41 x 10^-5mole dm^-3 B
• 1.0 x 10^-10 C
• 4.0 x 10^-20mole dm^-3 D

Extent to H₂ + L₂ à2Hl can be increased by :

• Increasing temperature.

  A

• Increasing product.

  B

• Increasing pressure.

  C

• Adding a catalyst.

  D

• 
  A
• 
  B
• 
  C
• 
  D

For what value ofK_{c almost forward reaction is complete :}

• K_{c =} 10³⁰

  A

• K_{c =} 10^-30

  B

• K_{c =} 0

  C

• K_{c =} 1

  D

• Shift reaction toward forward direction A
• Shift reaction backward B
• Lower the value of K_c C
• No change in reaction D

If pH of buffer of 1 mole dm^-3of HCOOH + 0.1 mole dm^-3HCOONa having pKa = 3.78 is

• 1.78 A
• 2.78 B
• 3.78 C
• 4.78 D

• Le-chatlier's principle A
• Only adding catalyst B
• Decreasing pressure C
• Decreasing temperature D

When the rate of formation of reactants is equal to the rate of formation of products, this is known as

• Chemical reaction A
• Chemical equilibrium B
• Chemical kinetics C
• None D

In a reversible reaction, two substances are in equilibrium. If the concentration of each one is reduced to half, the equilibrium constant will be

• Reduced to half of its original value A
• Doubled B
• Same C
• Reduced to one fourth its original value D

• Favour the formation of N₂O₄ A
• Favour the decomposition of N₂O₄ B
• Not alter the equilibrium C
• Stop the reaction D

When a weak acid is dissolved in water or a weak base dissolved in water, then in both cases the conjugate acid base pair is produced. The ionization constants K_aand K_bof a pair are related with each other as

• K_a= K_b A
• K_a. K_b= K_w B
• K_a. K_w= K_b C
• K_b. K_w= K_a D

• 
  A
• 
  B
• 
  C
• 
  D

• 0.073 A
• 0.147 B
• 0.05 C
• 0.026 D

A solution of NaOH has pH = 13, then concentration of NaOH is

• 10^-13M A
• 10¹³M B
• 10^-1M C
• 10⁺¹M D

• 0.12 A
• 0.50 B
• 0.25 C
• 4.00 D

Which of the following factors will favour the reverse reaction in a chemical equilibrium?

• Increase in concentration of one of the reactants A
• Increase in concentration of one of the products B
• Removal of one of the products regularly C
• None of these D

When rate of forward reaction is equal to rate of backward reaction, then the equilibrium established is called

• Chemical equilibrium A
• Static equilibrium B
• Dynamic equilibrium C
• None of these D

• 0.60 A
• 1.67 B
• 0.66 C
• 2.6 D

• Moles per dm³ A
• Partial pressures B
• Number of moles C
• Mole fractions D

• 0.02 A
• 0.2 B
• 50 C
• 25 D

A chemical reaction is in equilibrium when

• Formation of product is minimum A
• Reactants are completely transformed into products B
• Rates of forward and backward reactions are equal C
• Equal amounts of reactants and products are present D

strength of an acid can be determined by

• P^ka A
• P^kp B
• P^oH C
• P^kw D