[OH-]=(0.1×1.8×10*-5)²=1.34×10*-3[H+]=1×10*14/1.34×10*-3=7.5×10*-12PH=-lg7.5×10*-12=11.1
pOH=(pKb-lgc)/2=(4.74 -(-2))/2=3.37pH=14-3.37=10.63