ECAT Pre Engineering Chemistry Chapter 8 MCQ Test With Answer

pH and pKa of the buffer are related by Henderson equation which is

• 
  A
• 
  B
• 
  C
• 
  D

• 0.60 A
• 1.67 B
• 0.66 C
• 2.6 D

I a chemical reaction equilibrium is said to have been established when :

• Rate of opposing reactions are equal. A
• Rate constants of opposing reactions are equal. B
• Opposing reactions stop. C
• Concentration of reactants and products are equal D

• 0.12 A
• 0.50 B
• 0.25 C
• 4.00 D

• 4 mole per dm³ A
• 2 mole per dm³ B
• 0.33 mole per dm³ C
• 0.67 mole per dm³ D

The ionic product of H⁺ions and OH^-in water is called ionization constant of water Kw. The value of Kw at 25°C is

• 0.11 x 10^-14 A
• 0.30 x 10^-14 B
• 1.0 x 10^-14 C
• 3 x 10^-14 D

K_bvalue of NH₄OH is 1.81 x 10^-5and its conjugate acid has K_a= 5.7 x 10^-10pKb of the base is 4.74, pKa of its conjugate acid is

• -4.74 A
• 4.74 B
• 10 C
• 9.26 D

The substance which increases rate of reaction but remains unchanged at the end of reaction is called :

• Catalyst. A
• Indicator. B
• Promoter. C
• Activator. D

Which of the following in an example of reversible reaction

• 
  A
• 
  B
• 
  C
• 
  D

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

N₂ + 3H₂ ⇌2NH₃

The unit of K_c for tis reaction will be:

• mol² dm^-6

  A

• mol^-2 dm⁺⁶

  B

• mol dm^-3

  C

• mol^-1 dm⁺³

  D

• 
  A
• 
  B
• 
  C
• 
  D

N₂ +3H₂⇌ 2NH_{3 + Heat for above equation, themaximum product will be obtained at :}

• Low temperature at high pressure. A
• High temperature and low pressure. B
• High temperature and high pressure. C
• Low temperature at low pressure. D

On passing HCI gas through a saturated solution of commercial sodium chloride, pure crystals of NaCI are precipitated due to

• Increase in pH of the solution A
• Decrease in pH of the solution B
• Common ion effect C
• Increase in ionization of NaCl D

The relation between Kc and Kp is

• 
  A
• 
  B
• 
  C
• 
  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

K_bfor NH₄OH is 1.81 x 10^-5, then K_avalue of its conjugate base is

• 1.81 x 10⁺⁵ A
• 1.81 x 10^-9 B
• 5.5 x 10^-9 C
• 5.5 x 10^-10 D

Which of the following favours the reverse reaction in chemical equilibrium?

• Increasing the concentration of the reactant A
• Removal of the least one of the products at regular intervals B
• Increasing the concentration of one or more of the products C
• None of these D

Law of mass action states that rate of chemical reaction is directly proportional to the product of active masses of the reactants. The term active mass means

• Mass in grams converted to products A
• Number of moles B
• Number of moles per dm³of reactants C
• Total pressures of the reactants D

A buffer of a 0.09 molar acetic acid and 0.11 molar sodium acetate has pH = 4.83. If 0.01 mole NaOH in 1 dm³of the buffer solution is added, then pH of the buffer becomes

• 4.74 A
• 4.92 B
• 5.0 C
• 4.0 D

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

pH of 0.1 molar HCl solution is

• 1 A
• zero B
• 13 C
• 14 D

The pH of 10^-3mole dm^-3of an aqueous solution of H₂SO₄is

• 3.0 A
• 2.7 B
• 2.0 C
• 1.5 D

For the above reaction the relationship b/w k_c and k_p will be :

• K_p = K_cRT

  A

• Kp = K_c(RT)_-1

  B

• K_p = K_c(RT)_-2

  C

• K_c = K_p

  D

• Total pressure A
• Amount of A₂and B₂ B
• Temperature C
• Catalyst D

• 1 A
• 10 B
• 5 C
• 0.33 D

• KC = KP A
• Kp = KcRT B
• Kp = kc(RT)^-2 C
• Kp = Kc(RT)^-1 D

• 450°C A
• 250°C B
• 850°C C
• 1000°C D

• Moles^-2dm⁺⁶ A
• No units B
• Mole dm^-3 C
• Mole^-1dm^-3 D