ECAT Pre Engineering Chemistry Chapter 8 MCQ Test With Answer

The correct relation b/wK_{c and}K_{p is :}

• K_p = K_c[P/N] ^Δn

  A

• K_{c =} K_p(RT) ^Δn

  B

• K_{p =} K_c(RT) ^Δn

  C

• K_{p =} K_c(RT) ^Δn

  D

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

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

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

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

pH of 1 molar NaOH is

• 7 A
• zero B
• 14 C
• 10 D

Whenever a week base is dissolved in water, it give its conjugate acid. similarly a weak acid in water produces its conjugate base. This conjugate acid-base pair concept is stated by

• Law of mass action A
• Le-charlier's principle B
• Common ion effect C
• Lowery Bronsted concept D

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

• Kw A
• Kn B
• Ka C
• Kb D

ph of the buffer CH₃COOh + CH₃COONa is 3.76. If the mixture contains 1 molar acetic acid and 0.1 molar sodium acetate, then pKa of this buffer is

• 3.76 A
• 4.76 B
• 5.76 C
• 6.76 D

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

• Forward A
• Backward B
• Already in equilibrium C
• K_cis never less D

strength of an acid can be determined by

• P^ka A
• P^kp B
• P^oH C
• P^kw D

• 0.5 A
• 4.0 B
• 2.5 C
• 0.25 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

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

• 3.0 A
• 2.7 B
• 2.0 C
• 1.5 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

A solution having pH = 4 its OH^-ion concentration in mole dm^-3is

• 1.0 x 10^-4 A
• 1.0 x 10^-10 B
• 1.0 x 10^-14 C
• 1 x 10⁰ D

For which system does the equilibrium constant, KC has units of concentration

• 
  A
• 
  B
• 
  C
• 
  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

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

• Ag⁺ and NO_3- only

  A

• Ag⁺ and Ba² and NO^-3

  B

• Ba² and NO^-3

  C

• Ba² and NO^-3 and Cl-

  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

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

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 chemical reaction A---------->B is said to be in equilibrium when :

• Rate of transformation of A to B is equal to B to A. A
• 50% reactant has been changed to B. B
• Conversion of A to B is 50% complete C
• Complete conversion of A to B has taken place. D

A large value of K_cmeans that at equilibrium :

• Less reactant and more products. A
• Reactants and product in same amounts. B
• More reactants and less products. C
• None of above. D

• High temperature A
• Low temperature B
• Low pressure C
• High pressure D

In 1000 molecules of 0.001 M acetic acid the number of H⁺ions is 12.6, then its percentage of ionization is

• 1.33% A
• 1.26% B
• 12.6 C
• 1% D