Answer :
Final Answer:
The degree of dissociation of 0.01 M acetic acid in the presence of 0.01 M HCl is approximately 0.005.
Explanation:
Acetic acid (CH₃COOH) is a weak acid with a dissociation constant (Ka) of 1.69 x 10⁻⁵ at a given temperature. The degree of dissociation (α) represents the fraction of acid molecules that ionize in the solution.
In the presence of HCl, a strong acid, the equilibrium shifts towards complete ionization of HCl, leaving CH₃COOH primarily undissociated. Since acetic acid is weak, its dissociation is negligible compared to HCl. The concentration of H⁺ ions mainly comes from HCl.
Denoting the initial concentration of acetic acid as C₀ (0.01 M) and the degree of dissociation as α, the concentration of H⁺ ions from HCl is equal to the initial HCl concentration (0.01 M). The concentration of H⁺ ions from acetic acid (C₀ * α) is much smaller. As the strong acid dissociates almost completely, C₀ * α is negligible compared to 0.01 M.
Therefore, the practical degree of dissociation for acetic acid in the presence of 0.01 M HCl is approximately the same as without HCl, which is 1.69 x 10⁻⁵. Thus, the final answer is that the degree of dissociation is approximately 0.005.
