Question

The degree of dissociation of weak acid is 7.2 x 10^-4 . What is the value of it’s percent dissociation in 0.025 M solution?

• A. 0.80%
• B. 0.062%
• C. 8.2%
• D. 0.072%

Answer 1

The Correct Option is D

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%.

Answer 2

Given:
α = 7.2 × 10⁻⁴
Initial concentration of weak acid = 0.025 M
Percent dissociation is calculated as: Percent dissociation =α×100
Substituting the value of α: Percent dissociation =\(7.2\times 10^{-4}\times 100 = 0.072%\) %  
Thus, the correct option is (D) 0.07%.