Equilibrium · Question 46

Which of these is least likely to act as a Lewis base ?

1. BF3
2. PF3
3. CO
4. F-

Identify the correct order of solubility in aqueous medium.

1. Na2S > CuS > ZnS
2. Na2S > ZnS > CuS
3. CuS > ZnS > Na2S
4. ZnS > Na2S > CuS

Accumulation of lactic acid (HC3H5O3), a monobasic acid in tissues leads to pain and a feeling of fatigue. In a 0.10 M aqueous solution, lactic acid is 3.7% dissociated. The value of dissociation constant, Ka, for this acid will be

1. 1.4 10-5
2. 1.4 10-4
3. 3.7 10-4
4. 2.8 10-4

At 100 the Kw of water is 55 times its value at 25 . What will be the pH of neutral solution? (log 55 = 1.74)

1. 7.00
2. 7.87
3. 5.13
4. 6.13

The values of Ksp of CaCO3 and CaC2O4 are 4.7 10-9 and 1.3 10-9 respectively at 25 . If the mixture of these two is washed with water, what is the concentration of Ca2+ ions in water ?

1. 5.831 10-5 M
2. 6.856 10-5 M
3. 3.606 10-5 M
4. 7.746 10-5 M

The dissociation constant of weak acid is 1 10-4. In order to prepare a buffer solution with a pH = 5, the [Salt]/[Acid] ratio should be

1. 4 : 5
2. 10 : 1
3. 5 : 4
4. 1 : 10

Given that the equilibrium constant for the reaction, 2SO2(g) + O2(g) 2SO3(g) has a value of 278 at a particular temperature. What is the value of the equilibrium constant for the following reaction at the same temperature ? SO3(g) SO2(g) + 12O2(g)

1. 1.8 10-3
2. 3.6 10-3
3. 6.0 10-2
4. 1.3 10-5

Given the reaction between 2 gases represented by A2 and B2 to give the compound AB(g), A2(g) + B2(g) 2AB(g) At equilibrium, the concentration of A2 = 3.0 10-3 M, of B2 = 4.2 10-3 M, of AB = 2.8 10-3 M If the reaction takes place in a sealed vessel at 527 , then the value of Kc will be

1. 2.0
2. 1.9
3. 0.62
4. 4.5

pH of a saturated solution of Ba(OH)2 is 12. The value of solubility product (Ksp) of Ba(OH)2 is

1. 3.3 10-7
2. 5.0 10-7
3. 4.0 10-6
4. 5.0 10-6

Equimolar solutions of the following substances were prepared separately. Which one of these will record the highest pH value ?

1. BaCl2
2. AlCl3
3. LiCl
4. BeCl2