Ionization of Weak Acids and Weak Bases

IMPORTANT

Ionization of Weak Acids and Weak Bases: Overview

This topic covers concepts such as Degree of Dissociation for Acids and Bases, Ostwald's Dilution Law, Common Ion Effect, Strengths of Acids and Bases, Relative Strengths of Acids and Bases, Strength of Acids, Strength of Bases, etc.

Important Questions on Ionization of Weak Acids and Weak Bases

EASY
IMPORTANT

Explain the reason for the smaller value of higher order ionization constants than the lower order ionization constant of polyacidic bases.

EASY
IMPORTANT

Define polyacidic bases and give some examples.

MEDIUM
IMPORTANT

Ionisation constant of  CH3COOH is 1.7×10-5 and concentration of H+ ions is 3.4×10-4. Then, the initial concentration of CH3COOH is 

MEDIUM
IMPORTANT

Which of the following will occur if a 0.1 M solution of a weak acid is diluted to 0.01 M at constant temperature?

MEDIUM
IMPORTANT

The Ka values of formic acid and acetic acid are respectively 1.77×10-4 and 1.75×10-5. The ratio of acid strength of 0.1 N acids is

EASY
IMPORTANT

Which of the following is a weak alkali?

EASY
IMPORTANT

Define the degree of dissociation of electrolytes.

MEDIUM
IMPORTANT

What is common ion effect? Write an example.

MEDIUM
IMPORTANT

NH3 is dissolved in water.

NH3 + H2O NH4++OH-

Its base dissociation constant is given by:

EASY
IMPORTANT

Select the weak base from the following:

MEDIUM
IMPORTANT

The increasing order of base strength is

MEDIUM
IMPORTANT

A 0.025 M aqueous solution of a monobasic acid had a freezing point change of (-0.060)°C. What is the pKa for the acid? Given that molal depression constant Kf of  H2O is 1.86 K kg mol-1.

(log 2=0.3, log 3=0.5, log 4=0.6)

HARD
IMPORTANT

Arrange in decreasing order of acidity?

(P) Question Image (Q) Question Image (R) Question Image (S) Question Image

HARD
IMPORTANT

The correct order of increasing H3O+ in the following aqueous solution is 

HARD
IMPORTANT

What is the decreasing order of strength of bases? 
OH-, NH2-, H-CC- and CH3-CH2-

HARD
IMPORTANT

The relation between pH, pKa and concentration c of the solution of a weak acid can be written as _____.

(A) pH=12pKa-logc

(B) pH=12pKa+logc

(C) pH=pKa-logc

Enter the correct answer as A, B or C.

EASY
IMPORTANT

If Ka is the ionization constant of a weak acid and Kb is that of the conjugate base, then pKa+pKb=2Y. If the value of ionic product of water is 1.0×10-14 then the value of Y=_____.

MEDIUM
IMPORTANT

If the acid-base reaction HA(aq)+B-(aq)HB(aq)+A-(aq) has a Keq=10-4 , then is the given statement  correct or incorrect?

 A- is stronger base than B-.

HARD
IMPORTANT

If the acid-base reaction HA(aq)+B-(aq)HB(aq)+A-(aq) has a Keq=10-4  then the given statement is correct or incorrect?

B- is stronger acid than A-.

MEDIUM
IMPORTANT

If the acid-base reaction HA(aq)+B-(aq)HB(aq)+A-(aq) has a Keq=10-4, which of the following statements are true?

(i)  HA is more acidic than HB.

(ii) HB is more acidic than HA.

(iii) HA and HB have the same acidity.