jika garam NaX 0,01 M mempunyai pH=9 harga Ka asam HX adalah sebesar???

NaX 0,01 M
pH = 9

Ka HX ... ?

pH garam NaX = 9
pOH = 14 - pH
pOH = 14 - 9
pOH = 5
-log [OH^-] = 5
[OH^-] = 10^-5

........ [OH^-] = √( Kw/Ka × M )
.......... 10^-5 = √( 10^-14/Ka × 0,01 )
.......... 10^-5 = √( 10^-14/Ka × 10^-2 )
.......... 10^-5 = √( 10^-16/Ka )
.... (10^-5)^2 = (√( 10^-16/Ka ) )^2
........ 10^-10 = 10^-16/Ka
.10^-10 × Ka = 10^-16
............... Ka = 10^-16/10^-10
............... Ka = 10^-6