A buffer solution contains 100 mL of 0.01 M CH3COOH and 200 mL of 0.02 M CH3COONa.700 mL of water is added. pH before and after dilution are (pKa = 4.74)

In mixture (before dilution )[CH3COOH]=0.01×100300=0.013M[CH3COONa]=0.02×200300=0.043MpH=pKa+log.[salt][acid]=4.74+log.0043×30.01=4.74+log4=4.74+0.60=5.34On dilution , no change in pH will take place.pH (before) = pKa + log 4 =5.34Dilution has no effect on pH of buffer.