How many grams of solid sodium acetate should be added to 2.00 L of 0.184 M acetic acid solution to prepare a buffer with a pH of 4.140

Respuesta :

pH = pKa + log [NaAc]/[HAc]

4.140 = 4.74 + log x

log x = -0.60

x = [NaAc]/[HAc] = 0.25

moles HAc = 1.50 L x 0.287 mol/L = 0.431 moles

moles NaAc = 0.25 x 0.431 = 0.1078 moles NaAc

grams NaAc = 0.108 x 80 g/mole = 8.64 grams