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Equilibrium · Question 69

AIPMT 2009MCQEasy📈 Topic in 12% papers+4−1
1

Which of the following molecules acts as a Lewis acid?

  1. (CH3)2O
  2. (CH3)3P
  3. (CH3)3N
  4. (CH3)3B

Answer

(4) (CH3)3B

Solution

As per NCERT, a Lewis acid is an electron-pair acceptor.

(CH3)2O, (CH3)3P and (CH3)3N have lone pairs on O, P and N ⇒ they are Lewis bases.

In (CH3)3B, boron has only 6 valence electrons (incomplete octet) ⇒ it accepts an electron pair.

∴ (CH3)3B acts as a Lewis acid.

Answer: (4)

AIPMT 2009

Keep practising — Equilibrium

2

The ionization constant of ammonium hydroxide is 1.77 10-5 at 298 K. Hydrolysis constant of ammonium chloride is

  1. 6.50 10-12
  2. 5.65 10-13
  3. 5.65 10-12
  4. 5.65 10-10
AIPMT 2009
3

What is the [OH-] in the final solution prepared by mixing 20.0 mL of 0.050 M HCl with 30.0 mL of 0.10 M Ba(OH)2?

  1. 0.40 M
  2. 0.0050 M
  3. 0.12 M
  4. 0.10 M
AIPMT 2009
4

The dissociation equilibrium of a gas AB2 can be represented as: 2AB2(g) 2AB(g) + B2(g) The degree of dissociation is x and is small compared to 1. The expression relating the degree of dissociation (x) with equilibrium constant Kp and total pressure P is

  1. (2Kp/P)1/2
  2. (Kp/P)
  3. (2Kp/P)
  4. (2Kp/P)1/3
AIPMT 2008
5

If the concentration of OH- ions in the reaction Fe(OH)3(s) Fe3+(aq) + 3OH-(aq) is decreased by 1/4 times, then equilibrium concentration of Fe3+ will increase by

  1. 64 times
  2. 4 times
  3. 8 times
  4. 16 times
AIPMT 2008
6

Equal volumes of three acid solutions of pH 3, 4 and 5 are mixed in a vessel. What will be the H+ ion concentration in the mixture?

  1. 3.7 10-3 M
  2. 1.11 10-3 M
  3. 1.11 10-4 M
  4. 3.7 10-4 M
AIPMT 2008
7

The value of equilibrium constant of the reaction HI(g) 12H2(g) + 12I2(g) is 8.0. The equilibrium constant of the reaction H2(g) + I2(g) 2HI(g) will be

  1. 16
  2. 1/8
  3. 1/16
  4. 1/64
AIPMT 2008
8

The values of Kp for the reactions, X Y + Z ....(i) A 2B ....(ii) are in the ratio 9 : 1. If degree of dissociation of X and A be equal, then total pressure at equilibrium (i) and (ii) are in the ratio

  1. 36 : 1
  2. 1 : 1
  3. 3 : 1
  4. 1 : 9
AIPMT 2008
9

Equimolar solutions of the following were prepared in water separately. Which one of the solutions will record the highest pH?

  1. MgCl2
  2. CaCl2
  3. SrCl2
  4. BaCl2
Out of syllabusAIPMT 2008
10

Which one of the following ionic species has the greatest proton affinity to form stable compound?

  1. NH2-
  2. F-
  3. I-
  4. HS-
AIPMT 2007
11

The equilibrium constants of the following are N2 + 3H2 2NH3; K1 N2 + O2 2NO; K2 H2 + 12O2 H2O; K3 The equilibrium constant (K) of the reaction: 2NH3 + 52O2 2NO + 3H2O will be

  1. K2K33/K1
  2. K2K3/K1
  3. K23K3/K1
  4. K1K33/K2
AIPMT 2007

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