The pH of blood is maintained by CO₂ by and H₂CO₃ in the body and chemical constituents of blood. This phenomenon is called:

1. colloidal                           

2. buffer action

3. acidic                               

4. salt balance

Incorrect statement among the following is: 

1. Addition of one drop of concentrated HCl in NH₄OH solution decreases pH of the solution.

2. A solution of the mixture of one equivalent of each of CH₃COOH and NaOH has a pH of 7

3. pH of pure neutral water is not zero.

4. A cold and concentrated H₂SO₄ has lower H⁺ ion concentration than a dilute solution of H₂SO₄ 

At temperature T, a compound AB₂ (g) dissociates according to the reaction 2AB₂$\rightleftharpoons$2AB(g) +B₂(g) with a degree of  dissociation x, which is small compared with unity. The expression for K_p, in terms of x and the total pressure P , is:

1. Px³/2                                 

2. Px²/3

3. Px³/3                                 

4. Px²/2

The rate constants for forward and backward reaction of hydrolysis is ester are 1.1 x10^-2 and 1.5x10^-3 per minute. Equilibrium constant for the reaction,                                                              

 CH₃COOC₂H₅ + H⁺ $\rightleftharpoons$ CH₃COOH + C₂H₅OH is

1. 4.33           

2. 5.33           

3. 6.33         

4. 7.33

What happens to pH of a solution when NH₄Cl crystal is added to a dilute solution of NH₄OH?

1. Decreases                                   

2. Increases

3. Remains unaffected                       

4. All of the above

For the reactions,

A $\rightleftharpoons$ B;                                  K_c = 2

B $\rightleftharpoons$ C;                                  K_c = 4

C $\rightleftharpoons$ D;                                  K_c = 6

K_c for the reaction, A $\rightleftharpoons$ D is:

1. (2+4+6)                       

2. (2x4)/6

3. (4x6)/2                         

4. 2x4x6

The phenomenon of interaction of anions and cations furnished by an electrolyte with the H⁺ and  OH^- ions of water to produce acidic nature or alkalinity is known as hydrolysis. In hydrolysis:

1. the pH may either increase or decrease

2. all the salts (except those made up with strong acid and base) undergo hydrolysis

3. the variation of pH depends upon the nature of salts as well as on the temperature

4. all of the above

For the reaction equilibrium,

2NOBr(g) $\rightleftharpoons$2NO(g) + Br₂(g), if $P_{\mathit{B}{\mathit{r}}_{\mathit{2}}}$ = P/9 at equilibrium and P is total pressure. The ratio of K_p/P is equal to:

1. 1/9               

2. 1/81

3. 1/27               

4. 1/3

In the system, CaF₂(s) $\rightleftharpoons$Ca²⁺ (aq) + 2F^-(aq), increasing the concentration of Ca²⁺ ions 4 times will cause the equilibrium concentration of F^- ions to change to:

1. 1/4 of the initial value

2. 1/2 of the initial value

3. 2 times of the initial value

4. none of the above

The addition of HCl does not suppress the ionization of: