ECAT Pre Engineering Chemistry Chapter 8 MCQ Test With Answer

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

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

2SO₂ + O₂ ⇌ 2SO₂ H= 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 V₂O₅ catalyst increase the equilibrium yield of Sulphur trioxide.
  D

A gas bulb is filled with NO₂gas and immersed in an ice bath at 0°C which becomes colourless after sometimes. This colourless gas will be

• NO₂ A
• N₂O B
• N₂O₄ C
• N₂O₅ 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

Buffers having pH less than 7 are made

• Mixture of weak acid + salt of it with strong base A
• Mixture of weak acid + salt of it with weak base B
• Mixture of weak base + salt of it with strong acid C
• Mixture of weak base + salt of it with weak base 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

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

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

If the difference of pKa values of the two acids is 2, then

• Acid with smaller pKa is 10 times stronger acid A
• Acid with greater pKa is 10 times stronger acid B
• Acid with smaller pKa is 100 times stronger acid C
• Acid with greater pKa is 100 times stronger acid D

• 0.12 A
• 0.50 B
• 0.25 C
• 4.00 D

Acetic acid is 1.33% ionized, In 1000 molecules of 0.1 M acetic acid the number of H⁺ions is

• 1.33 A
• 13.3 B
• 1.33 C
• 1 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

• 32 A
• 64 B
• 16 C
• 4 D

Which one of the following is not a buffer

• H₂CO₃+ NaHCO₃solution A
• H₃PO₄+ NaH₂PO₄solution B
• Hl + Nal solution C
• NH₄OH + NH₄CI solution D

• Low pressure A
• High pressure B
• High temperature C
• High concentration of SO₂ D

• 1 A
• 10 B
• 5 C
• 0.33 D

• Pressure change A
• Temperature change B
• Concentration change C
• Catalyst D

1 mole of N₂and 2 moles of H₂are allowed to react in a 1 dm³vessel. At equilibrium 0.8 mole of NH₃is formed. The concentration of H₂in the vessel is

• 0.6 mole A
• 0.8 mole B
• 0.2 mole C
• 0.4 mole 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

pH of water is 7, if 0.01 M NaOH is added, than its pH is

• 12 A
• 14 B
• zero C
• 10 D

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

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

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

• Kw A
• Kn B
• Ka C
• Kb D

• Complete conversion of A to B has taken place A
• Conversion of A to B is only 50% complete B
• Only 10% conversion of A to B has taken place C
• The rate of transformation of A to B is just equal to rate of transformation of B to A in the system D

• The value of K_pfalls with a rise in temperature A
• The value of K_pfalls with increasing pressure B
• Adding V₂O₅catalyst increase the equilibrium yield of sulphur trioxide equilibrium yield of sulphur trioxide C
• The value of K_pis equal to K_c 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

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

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