Calculate the molar concentration of ethanoic acid needed to prepare ethanoate buffer of PH 6.8 using 0.5m solution of sodium ethanoate. Pka of ethanoate acid is 0.127

Answer 1

Do you mean 0.5M. M means molar. m means molal.

pH = pKa + log (base)/(acid)
6.8 = 0.127 + log (0.5M/x)
Sovle for x.