AP EAMCET2010ChemistryIonic Equilibrium
The pH of 0.01 M solution of acetic acid is 5.0. What are the values of [ H ⁺ ] and K_a respectively?
Options
- A1 10⁻⁵ M , 1 10⁻⁸
- B1 10⁻⁵ M , 1 10⁻⁹
- C1 10⁻⁴ M , 1 10⁻⁸
- D1 10⁻³ M , 1 10⁻⁸
Correct answer
A. 1 10⁻⁵ M , 1 10⁻⁸
Step-by-step solution
Given, pH of 0.01 M CH ₃ COOH solution =5.0 Concentration, C of the solution =0.01 M [ H ⁺ ]=1 10^ - pH =1 10⁻⁵ ~mol / L =1 10⁻⁵ M Since, acetic acid is a weak acid and for weak acid, [ H ⁺ ]= K_a C [ H ⁺ ]^2=K_a CK_a= [ H ⁺ ]^2 C = (1 10⁻⁵ )^2 0.01 =1 10⁻⁸