tolong bantu pakai caranya ya!

pH asam HCOOH = pH asam HCl

HCl > H+ + Cl-

[HCl] = 0,02M
[H+] = 1 x 0,02
[H+] = 0,02M

pH = - log(2×10^-2)
pH = 2 - log2
pH = 2 - 0,3
pH = 1,7
[H+] = 10^-1,7 M

HCOOH = 0,1M

[H+] = akar Ka x [HCOOH]

(10^-1,7)^2 = Ka x ( 0,1 )

3,98×10^-4 = Ka x ( 0,1 )

Ka = 3,98×10^-3 =~ 4×10^-3