ECAT Pre Engineering Chemistry Chapter 8 MCQ Test With Answer

Which statement about the following equilibrium in correct?

2SO_{2 (g)}+ O_2(g)---------------2sO_3(g)H= - 188.3 KJ mol-1

• T value of K_{p falls witha rise in temperate.} A
• The value of K_{p falls withincreasing pressure}
  B
• Adding V_2O5catalyst increase the equilibrium yield of sulfur trioxide
  C
• The value of K_{p is equal to}K_p D
• 
  
  E

pH of the human blood which is essentially maintained constant due to carbonates, biocarbonates, phosphates etc., is

• 7.00 A
• 7.25 B
• 7.35 C
• 7.47 D

• 0.60 A
• 1.67 B
• 0.66 C
• 2.6 D

In an exothermic reaction, a 10° rise in temperature will

• Decrease the value of equilibrium constant A
• Double the value of K_c B
• Not produce any change in K_c C
• Produce some increase in K_c D

The concentration of reactants is increased by x, then equilibrium constant K becomes

• ln K/x A
• K/x B
• K + x C
• K D

The solubility product of Ca(OH)₂is 6.5 x 10^-6. The concentration of OH^-ions is

• 1.175 x 10^-2 A
• 2.35 x 10^-2 B
• 3.25 x 10^-3 C
• 3.25 x 10^-4 D

• 8 A
• 4 B
• 9 C
• 3 D

• Increase in concentration of 1 A
• Decrease in concentration of I₂ B
• Increase in temperature C
• Increase in total pressure D

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

The rate of forward reaction is two times that of the reverse reaction at a given temperature and identical concentration, K equilibrium is

• 0.5 A
• 1.5 B
• 2.5 C
• 2.0 D

Which of the following is a characteristic of a reversible reaction?

• It never proceeds to completion A
• It can be influenced by a catalyst B
• It proceeds only in the forward direction C
• Number of moles of reactants and products are equal 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

• Reaction occurs at STP A
• Reaction is exothermic B
• Reaction is endothermic C
• Number of moles of production and reactant are same D

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

pH of 0.1 molar HCl solution is

• 1 A
• zero B
• 13 C
• 14 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

An aqueous solution is neutral when its

• pH = 14 A
• pH = zero B
• pH = 7 C
• Kw = 10^-7 D

The solubility product of AgCl is 2.0 x 10^-3 mol² dm^-6 , The maximum concentration of Ag ion in the solution is :

• 2.0 x 10^-10 mol dm^-3

  A

• 1.41 x 10^-10 mol dm^-3

  B

• 1.0 x 10^-10 mol dm^-3

  C

• 4.0 x 10^-10 mol 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 ions in the filtrate

• 
  A
• 
  B
• 
  C
• 
  D

K_avalue of HF acid is 6.7 x 10^-15the acid is a

• Weak acid A
• Moderately strong acid B
• Strong acid C
• Very weak acid D

strength of an acid can be determined by

• P^ka A
• P^kp B
• P^oH C
• P^kw D

Base buffer solution can be prepared by mixing

• Weak acid and its salt A
• Strong acid and its salt with weak base B
• Weak base and its salt with strong acid C
• Strong base and its salt with weak acid D

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

Which one of the following is a buffer

• HCI + NaCI solution A
• CH₃COOH + CH₃COONH₄solution B
• H₂SO₄+ CaSO₄solution C
• CH₃COOH + CH₃COONa D

• Reversible reaction A
• Irreversible reaction B
• Spontaneous reaction C
• None of these D

Reactions that proceed on both sides and never go to completion are called

• Irreversible reactions A
• Reversible reactions B
• Opposing reactions C
• Spontaneous reactions 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

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

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

pKb value of NH₄OH is 4.74. If the concentration of NH₄OH is 1 molar containing 0.1 molar NH₄Cl, then pH of this buffer will be

• 3.74 A
• 10.26 B
• 4.74 C
• 9.26 D