What is the pH of buffer solution prepared by mixing 0.01 M weak acid and 0.02 M salt of weak acid with strong base ? ( pK _ a =4 680 )

Step-by-step solution

The Henderson-Hasselbalch equation for an acidic buffer is given by: pH = pK _ a + ( [ Salt ] [ Acid ] ) Given [ Acid ] = 0.01 M , [ Salt ] = 0.02 M , and pK _ a = 4.680 : pH = 4.680 + ( 0.02 0.01 ) = 4.680 + 2 Since 2 0.301 : pH = 4.680 + 0.301 = 4.981 The options are A) 4.379, B) 2.379, C) 4.981, D) 2.981, so the correct choice is C .