What is the amount of potassium acetate to be added to 1 litre of N/10 acetic acid to make a buffer solution of pH=4 using acetic acid and potassium acetate? The dissociation constant of acetic acid =2*10^-5

let the amount of potassium acetate  = m grams

M(CH₃COOK) = m/92 .........1

normality of acetic acid = molarity*1

M₍ CH₃COOH) = 0.1               

K_a = [salt][H⁺]/[acid]

  PH =4 means [H⁺] = 10^-4

K_a = M(CH₃COOK][H⁺]/[CH_3COOH]

2*10^-5 = [m/92][10^-4]/[10^-1]

 m= 1.84grams