Question 51 of 69intermediate🔧 ApplyNumerical3 marks

Calculate the degree of ionization of 0.05 M acetic acid if its pKapK_a value is 4.74. How is the degree of dissociation affected when its solution also contains (a) 0.01 M (b) 0.1 M in HCl?

(a)
Answer

α′=1.82×10−3\alpha' = 1.82 \times 10^{-3}

(b)
Answer

α′′=1.82×10−4\alpha'' = 1.82 \times 10^{-4}

Explanation

The degree of ionization of a weak acid is calculated using its ionization constant (KaK_a) and initial concentration. When a strong acid like HCl is added, it provides a common ion (H+H^+), which suppresses the dissociation of the weak acid due to the common ion effect. The new degree of dissociation is calculated by approximating the equilibrium expression using the concentration of the common ion.

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