no 4 dan 5 gan yang pinter kimia

4) [OH-]=√(kw/ka*Manion garam)
M=n/V
n=m/Mr
nCH3COOK= 0,1 mol
CH3COOK -> CH3COO- + K+
0,1 mol. 0,1 mol. 0,1 mol
[OH-] =√(10^-14/10^-5 * 0,1 mol) = 10^-5
pOH=-log[OH-] = 5
pH= 14-5=9

5) [H+]= √(kw*ka /kb)= √((10^-14*10^-5)/10^-9) = 10^-5
pH= 5