Atomos Test Generator Free PYQs ExamsMy practice Log in / Sign up free

Equilibrium

AIPMT 2012 (Prelims)MCQEasy📈 Topic in 25% papers+4−1
Ques. 1AIPMT 2012 (Prelims)

Buffer solutions have constant acidity and alkalinity because

  1. these give unionised acid or base on reaction with added acid or alkali
  2. acids and alkalies in these solutions are shielded from attack by other ions
  3. they have large excess of H+ or OH- ions
  4. they have fixed value of pH

Answer

(1) these give unionised acid or base on reaction with added acid or alkali

Solution

In an acidic buffer (CH3COOH+CH3COONa):

added acid: CH3COO-+H+ CH3COOH (unionised acid)

added alkali: CH3COOH+OH- CH3COO-+H2O

Similarly in a basic buffer (NH4OH+NH4Cl), added alkali gives unionised NH4OH: NH4++OH- NH4OH.

The added H+ / OH- is removed as a weakly ionised acid or base, so the pH stays almost constant.

Answer: (1)

Keep practising — Equilibrium

Ques. 2AIPMT 2011 (Mains)

In qualitative analysis, the metals of group I can be separated from other ions by precipitating them as chloride salts. A solution initially contains Ag+ and Pb2+ at a concentration of 0.10 M. Aqueous HCl is added to this solution until the Cl- concentration is 0.10 M. What will the concentrations of Ag+ and Pb2+ be at equilibrium ? ( Ksp for AgCl = 1.8 10-10, Ksp for PbCl2 = 1.7 10-5)

  1. [Ag+] = 1.8 10-7 M, [ Pb2+] = 1.7 10-6 M
  2. [Ag+] = 1.8 10-11 M, [ Pb2+] = 8.5 10-5 M
  3. [Ag+] = 1.8 10-9 M, [ Pb2+] = 1.7 10-3 M
  4. [Ag+] = 1.8 10-11 M, [ Pb2+] = 1.7 10-4 M
Ques. 3AIPMT 2011 (Prelims)

The value of H for the reaction X2(g) + 4Y2(g) 2XY4(g) is less than zero. Formation of XY4(g) will be favoured at

  1. high temperature and high pressure
  2. low pressure and low temperature
  3. high temperature and low pressure
  4. high pressure and low temperature
Ques. 4AIPMT 2011 (Prelims)

A buffer solution is prepared in which the concentration of NH3 is 0.30 M and the concentration of NH4+ is 0.20 M. If the equilibrium constant, Kb for NH3 equals 1.8 10-5, what is the pH of this solution? ( 2.7 = 0.43)

  1. 9.08
  2. 9.43
  3. 11.72
  4. 8.73
Ques. 5AIPMT 2011 (Prelims)

Which of the following is least likely to behave as Lewis base?

  1. H2O
  2. NH3
  3. BF3
  4. OH-
Ques. 6AIPMT 2011 (Prelims)

For the reaction, N2(g) + O2(g) 2NO(g), the equilibrium constant is K1. The equilibrium constant is K2 for the reaction, 2NO(g) + O2(g) 2NO2(g) What is K for the reaction, NO2(g) 12N2(g) + O2(g)

  1. 12K1K2
  2. 14K1K2
  3. [ 1K1K2 ]1/2
  4. 1K1K2
Ques. 7AIPMT 2010 (Mains)

The reaction, 2A(g) + B(g) 3C(g) + D(g) is begun with the concentrations of A and B both at an initial value of 1.00 M. When equilibrium is reached, the concentration of D is measured and found to be 0.25 M. The value for the equilibrium constant for this reaction is given by the expression

  1. [(0.75)3(0.25)] [(1.00)2(1.00)]
  2. [(0.75)3(0.25)] [(0.50)2(0.75)]
  3. [(0.75)3(0.25)] [(0.50)2(0.25)]
  4. [(0.75)3(0.25)] [(0.75)2(0.25)]
Ques. 8AIPMT 2010 (Prelims)

If pH of a saturated solution of Ba(OH)2 is 12, the value of its Ksp is

  1. 4.00 10-6 M3
  2. 4.00 10-7 M3
  3. 5.00 10-6 M3
  4. 5.00 10-7 M3
Ques. 9AIPMT 2010 (Prelims)

What is [H+] in mol/L of a solution that is 0.20 M in CH3COONa and 0.10 M in CH3COOH? Ka for CH3COOH = 1.8 10-5

  1. 3.5 10-4
  2. 1.1 10-5
  3. 1.8 10-5
  4. 9.0 10-6
Ques. 10AIPMT 2010 (Prelims)

In which of the following equilibrium Kc and Kp are not equal?

  1. 2NO(g) N2(g) + O2(g)
  2. SO2(g) + NO2(g) SO3(g) + NO(g)
  3. H2(g) + I2(g) 2HI(g)
  4. 2C(s) + O2(g) 2CO(g)
Ques. 11AIPMT 2010 (Prelims)

In a buffer solution containing equal concentration of B- and HB, the Kb for B- is 10-10. The pH of buffer solution is

  1. 10
  2. 7
  3. 6
  4. 4

All Equilibrium PYQs →

PDFDownload Equilibrium PYQs as PDF Free, with answer key and a QR code to every solution — print it or study offline⬇
All NEET Chemistry chapters