Given:
α = 7.2 × 10-4
and the initial concentration of the weak acid is 0.025 M.
The percent dissociation can be calculated using the formula:
Percent dissociation = α × 100
Substituting the given value of α:
Percent dissociation = 7.2 × 10-4 × 100 = 0.072%
Therefore, the correct option is (D) 0.07%.