Equilibrium

At 298 K, a certain buffer solution contains equal concentrations of X- and HX. Kb for X- is 10-10. What is the pH of this buffer solution?

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

Given below are certain reactions. Identify the reaction for which Kp Kc.

1. N2(g) + O2(g) 2NO(g)
2. H2O(g) + CO(g) H2(g) + CO2(g)
3. N2(g) + 3H2(g) 2NH3(g)
4. H2(g) + I2(g) 2HI(g)

In a qualitative analysis, Bi3+ is detected by appearance of precipitate of BiO(OH)(s). Calculate pH when the following equilibrium exists at 298 K : BiO(OH)(s) BiO+(aq) + OH-(aq), K = 4 × 10-10 (Given : log 2 = 0.3010)

1. 4.699
2. 5.286
3. 8.714
4. 9.301

The correct order of solubility of the given salts in water at 298 K is array|l|l| Salt & Ksp at 298 K \ AgBr & 5.0 10-13 \ Zn(OH)2 & 1.0 10-15 \ Hg2Cl2 & 1.3 10-18 \ array

1. Zn(OH)2 > AgBr > Hg2Cl2
2. Hg2Cl2 > Zn(OH)2 > AgBr
3. AgBr > Zn(OH)2 > Hg2Cl2
4. Hg2Cl2 > AgBr > Zn(OH)2

For the reaction A(g) 2B(g), the backward reaction rate constant is higher than the forward reaction rate constant by a factor of 2500, at 1000 K. [Given : R = 0.0831 L atm mol-1 K-1] Kp for the reaction at 1000 K is

1. 0.033
2. 0.021
3. 83.1
4. 2.077 105

Phosphoric acid ionizes in three steps with their ionization constant values Ka1, Ka2 and Ka3, respectively, while K is the overall ionization constant. Which of the following statements are true? Choose the correct answer from the options given below :

1. B, C and D only
2. A, B and C only
3. A and B only
4. A and C only

Higher yield of NO in N2(g) + O2(g) 2NO(g) can be obtained at [ H of the reaction = +180.7 kJ mol-1] Choose the correct answer from the options given below :

1. B, C, D only
2. A, C, D only
3. A, D only
4. B, C only

In which of the following equilibria, Kp and Kc are NOT equal?

1. PCl5(g) PCl3(g) + Cl2(g)
2. H2(g) + I2(g) 2HI(g)
3. CO(g) + H2O(g) CO2(g) + H2(g)
4. 2BrCl(g) Br2(g) + Cl2(g)

For the reaction 2A B + C, Kc = 4 10-3. At a given time, the composition of reaction mixture is: [A] = [B] = [C] = 2 10-3 M. Then, which of the following is correct?

1. Reaction is at equilibrium.
2. Reaction has a tendency to go in forward direction.
3. Reaction has a tendency to go in backward direction.
4. Reaction has gone to completion in forward direction.

Consider the following reaction in a sealed vessel at equilibrium with concentrations of N2 = 3.0 10-3 M, O2 = 4.2 10-3 M and NO = 2.8 10-3 M. 2NO(g) N2(g) + O2(g) If 0.1 mol L-1 of NO(g) is taken in a closed vessel, what will be degree of dissociation ( ) of NO(g) at equilibrium?

1. 0.00889
2. 0.0889
3. 0.8889
4. 0.717

At a given temperature and pressure, the equilibrium constant values for the equilibria are given below: 3A2 + B2 2A3B, K1 A3B 32A2 + 12B2, K2 The relation between K1 and K2 is :

1. K12 = 2K2
2. K2 = K12
3. K1 = 1 K2
4. K2 = 1 K1

For the reaction in equilibrium N2(g) + 3H2(g) 2NH3(g), H = -Q Reaction is favoured in forward direction by:

1. use of catalyst
2. decreasing concentration of N2
3. low pressure, high temperature and high concentration of ammonia
4. high pressure, low temperature and higher concentration of H2

The ratio of solubility of AgCl in 0.1 M KCl solution to the solubility of AgCl in water is: (Given : Solubility product of AgCl = 10-10)

1. 10-4
2. 10-6
3. 10-9
4. 10-5

Amongst the given options which of the following molecules/ion acts as a Lewis acid?

1. H2O
2. BF3
3. OH-
4. NH3

The equilibrium concentrations of the species in the reaction A + B C + D are 2, 3, 10 and 6 mol L-1, respectively at 300 K. G for the reaction is (R = 2 cal/mol K)

1. -137.26 cal
2. -1381.80 cal
3. -13.73 cal
4. 1372.60 cal

For the reaction N2(g) + 3H2(g) 2NH3(g), H = -92.4 kJ mol-1. The yield of ammonia increases on

1. increasing temperature
2. decreasing pressure
3. increasing pressure
4. adding a catalyst

The pH of the solution containing 50 mL each of 0.10 M sodium acetate and 0.01 M acetic acid is [Given pKa of CH3COOH = 4.57]

1. 5.57
2. 3.57
3. 4.57
4. 2.57

3O2(g) 2O3(g) for the above reaction at 298 K, Kc is found to be 3.0 10-59. If the concentration of O2 at equilibrium is 0.040 M then concentration of O3 in M is

1. 4.38 10-32
2. 1.9 10-63
3. 2.4 1031
4. 1.2 1021

0.01 M acetic acid solution is 1% ionised, then pH of this acetic acid solution is :

1. 1
2. 3
3. 2
4. 4

Kp for the following reaction is 3.0 at 1000 K. CO2(g) + C(s) 2CO(g) What will be the value of Kc for the reaction at the same temperature? (Given : R = 0.083 L bar K-1 mol-1)

1. 3.6
2. 0.36
3. 3.6 10-2
4. 3.6 10-3

The pKb of dimethyl amine and pKa of acetic acid are 3.27 and 4.77 respectively at T (K). The correct option for the pH of dimethyl ammonium acetate solution is :

1. 6.25
2. 8.50
3. 5.50
4. 7.75

Hydrolysis of sucrose is given by the following reaction. Sucrose + H2O Glucose + Fructose If the equilibrium constant (Kc) is 2 1013 at 300 K, the value of r G at the same temperature will be :

1. 8.314 J mol-1 K-1 300 K (2 1013)
2. 8.314 J mol-1 K-1 300 K (3 1013)
3. -8.314 J mol-1 K-1 300 K (4 1013)
4. -8.314 J mol-1 K-1 300 K (2 1013)

Find out the solubility of Ni(OH)2 in 0.1 M NaOH. Given that the ionic product of Ni(OH)2 is 2 10-15.

1. 2 10-8 M
2. 1 10-13 M
3. 1 108 M
4. 2 10-13 M

Conjugate base for Brönsted acids H2O and HF are :

1. OH- and F-, respectively
2. H3O+ and H2F+, respectively
3. OH- and H2F+, respectively
4. H3O+ and F-, respectively

pH of a saturated solution of Ca(OH)2 is 9. The solubility product ( Ksp) of Ca(OH)2 is :

1. 0.125 10-15
2. 0.5 10-10
3. 0.5 10-15
4. 0.25 10-10

Which will make basic buffer?

1. 100 mL of 0.1 M HCl + 200 mL of 0.1 M NH4OH
2. 100 mL of 0.1 M HCl + 100 mL of 0.1 M NH4OH
3. 50 mL of 0.1 M NaOH + 25 mL of 0.1 M CH3COOH
4. 100 mL of 0.1 M CH3COOH + 100 mL of 0.1 M NaOH

Following solutions were prepared by mixing different volumes of NaOH and HCl of different concentrations : pH of which one of them will be equal to 1?

1. B
2. A
3. D
4. C

The solubility of BaSO4 in water is 2.42 10-3 g L-1 at 298 K. The value of its solubility product (Ksp) will be (Given molar mass of BaSO4 = 233 g mol-1)

1. 1.08 10-10 mol2 L-2
2. 1.08 10-12 mol2 L-2
3. 1.08 10-14 mol2 L-2
4. 1.08 10-8 mol2 L-2

Which one of the following conditions will favour maximum formation of the product in the reaction A2(g) + B2(g) X2(g), rH = -X kJ ?

1. Low temperature and high pressure
2. Low temperature and low pressure
3. High temperature and high pressure
4. High temperature and low pressure

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