The dissociation constants for acetic acid and HCN at 25^o C are 1.5 X 10^-5 and 4.5 x 10^-10 respectively. The equilibrium constant for the equilibrium,

CN^- + CH₃COOH  and HCN + CH₃COO^-

would be

• 3 x 10⁵

• 3.0 x 10^-5

• 3.0 x 10^-4

• 3.0 x 10^-4

32.

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?

• 1.11 x 10^-4 M

• 3.7 x 10^-4 M 

• 3.7 x 10^-3 M

• 3.7 x 10^-3 M

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 

• 8 times

• 16 times

• 64 times

• 64 times

Base strength of 



is in the order of 

• (2) > (1) > (3)

• (3) > (2) > (1) 

• (1) > (3)> (2) 

• (1) > (3)> (2) 

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

• SrCl₂

• BaCl₂

• MgCl₂

• MgCl₂

The dissociation equilibrium  of 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 K_p and total pressure p is 

• (2K_p / p)

• (2K_p/p)^1/3

• (2K_p/p)^1/2

• (2K_p/p)^1/2

The value of K_P1 and K_p2 for the reactions

X ⇌ Y +Z  ... (i)
A ⇌ 2B    ... (ii)

are in the ratio of 9:1. if the degree of dissociation of X and A be equal, then the total pressure at equilibrium (i) and (ii) are in the ratio

• 3:1

• 1:9

• 36:1

• 36:1

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

• 1/16

• 1/64

• 16

• 16

Calculate the pOH of a solution at 25⁰C that contains 1 x 10^-10 M of hydronium ions.

• 7

• 4

• 9

• 9

A Weak acid, H_A has a K_a of 1.00 x 10^-5. If 0.100 mole of this percentage of acid dissociated at equilibrium is closest to:

• 99.0%

• 1.00%

• 99.9 %

• 99.9 %