JEE Main202228 Jun 2022Evening ShiftChemistryIonic EquilibriumActual
A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4 . The ratio of CH 3 CH 2 COO - CH 3 CH 2 COOH required to make buffer is Given : K a CH 3 CH 2 COOH = 1 . 3 × 10 - 5
Options
- A0 . 03
- B0 . 13
- C0 . 23
- D0 . 33
Correct answer
B. 0 . 13
Step-by-step solution
Henderson's equation for calculating p H of acidic buffer solutions is given as pH = pK a + log Salt Acid pH = pK a + log CH 3 COO - CH 3 COOH 4 = 5 - log ( 1 . 3 ) + log CH 3 COO - CH 3 COOH log 1 . 3 × 10 - 1 = log CH 3 COO - CH 3 COOH CH 3 COO - CH 3 COOH = 0 . 13