UNIT 8: Ionic Equilibrium - Online Test
Q1. The hydrogen ion concentration of a buffer solution consisting of a weak acid and its salts is given by
Answer : Option A
Explaination / Solution:
According to Henderson equation
pH = pKa + log ([salt]/[acid])
ie. - log [H+ ] = -
log Ka +log ([salt] / [acid])
-log[H+] = log ([salt]/ [acid]) ×
(1/Ka)
log (1/[H+]) = log ([salt]/ [acid]) × (1/Ka)
∴[H+] = Ka
{[acid] / [salt] }
Q2. Which of the following relation is correct for degree of hydrolysis of ammonium acetate?
Answer : Option C
Explaination / Solution:
h= √{ (Kh) / (Ka
.Kb) }
Q3. Dissociation
constant of NH4OH is 1.8 ×10-5
the hydrolysis constant of NH4Cl would be
Answer : Option B
Explaination / Solution:
Kh = Kw/Kb =
1×10-14 / 1.8×10-5
= 0.55×10-9
= 5.5×10-10
