For a solution containing 0.1 M acetic acid ( ) and 0.2 M sodium acetate, the degree of association will be:
0.4
0.35
0.45
0.6
The degree of association for acetic acid is given by the formula, . Here, i is the Van't Hoff factor, which is 2 for acetic acid. Therefore, . Now, for sodium acetate, i = 2 (as it dissociates into and acetate ions). Hence, its degree of association is . The overall degree of association for the solution is given by the formula, . Here, are the activity coefficients for sodium acetate and acetic acid, respectively. Assuming their values to be equal to 1 (which is a good approximation for dilute solutions), we get, . Hence, the overall degree of association is , where . This gives