ECAT Pre Engineering Chemistry Chapter 8 MCQ Test With Answer

Almost forward reaction is complete when value of k_{c :}

• Neither larger nor very small. A
• Very small. B
• Very large. C
• Negligible. D

2SO₂+ O₂⇌2SO₂H= 188KJ mole^-1

Which statement about following equilibrium is correct :

• The value ofK_pfalls with arise in temperature.

  A

• The value ofK_pis equal tok_c.

  B

• The value ofK_pfalls with the increase pressure.

  C

• Adding V₂O₅catalyst increase the equilibrium yield of Sulphur trioxide.

  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

At certain temperature, 50% of HI is dissociated into H₂and I₂the equilibrium constant is

• 1.0 A
• 3.0 B
• 0.5 C
• 0.25 D

An excess of aqueous silver nitrate is added to aqueous barium chloride and precipitate is removed by filtration. What are the main ions in the filtrate

• 
  A
• 
  B
• 
  C
• 
  D

• 0.12 A
• 0.50 B
• 0.25 C
• 4.00 D

• At equilibrium there is no further change in the concentration of Hl A
• At equilibrium concentration of l₂remains constant B
• At equilibrium concentration of H₂remains unaltered C
• At equilibrium the rate of formation of Hl is equal to the rate of decomposition of Hl 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

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

The avtive mass of 64 g of HI in a two litre flask would be

• 2 A
• 1 B
• 5 C
• 0.25 D

Ammonium carbonate when heated to 200°C gives a mixture of NH₃and CO₂vapour with a density of 13.0. What is the degree of dissociation of ammonia carbonate?

• 3/2 A
• 1/2 B
• 2 C
• 1 D

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

A solution has pH = 0, its H⁺ion concentration is

• 1 x 10^-14 A
• 1 x 10¹⁴ B
• 1 x 10¹ C
• 1 D

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

pH of 1 molar NaOH is

• 7 A
• zero B
• 14 C
• 10 D

• Temperature is increased A
• Pressure is increased B
• HCl is added C
• HCl is removed 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

• Introduction of an inert gas at constant volume A
• Introduction of PCl₃(g) at constant B
• Introduction of PCl₅(g) at constant volume C
• Introduction of Cl₂at constant volume D

• 
  A
• 
  B
• 
  C
• 
  D

Le-chatlier's principle is applied on the reversible reaction in order to

• Determine the rate of reaction A
• Predict the direction of reaction B
• Determine the extent of reaction C
• Find best conditions for favorable shifting the position of equilibrium 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

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

Which of the following in an example of reversible reaction

• 
  A
• 
  B
• 
  C
• 
  D

• 
  A
• 
  B
• 
  C
• 
  D

• Decrease in temperature favour more dissolution of the salt A
• Increase in temperature favour more dissolution of the salt B
• Lowering pressure favour more dissolution of the salt C
• Increasing pressure favour more dissolution of the salt D

In which of the following cases, the reaction goes farthest to completion

• K = 10³ A
• K = 10^-2 B
• K = 10 C
• K = 10⁰ D

The solubility of PbF₂is 2.6 x 10^-3mole dm^-3 then its solubility product is

• 2.6 x 10^-3 A
• 6.76 x 10^-6 B
• 5.2 x 10^-6 C
• 7.0 x 10^-8 D

For which system does the equilibrium constant, kc has units of (concentration) ?

• N₂+3H_2-------2NH₃

  A

• H₂+L₂---------2HL

  B

• 2NO₂----------N₂O₄

  C

• 2HF--------H2+F₂

  D

Extent to H₂ + L₂ à2Hl can be increased by :

• Increasing temperature.

  A

• Increasing product.

  B

• Increasing pressure.

  C

• Adding a catalyst.

  D

N₂ + O₂ ⇌2NO

The unit of K_c for tis reaction will be:

• No unit

  A

• mol^-2 dm^-3

  B

• mol^-1 dm^-3

  C

• mol^-2 dm⁺³

  D