What is the `pH`of `0.01M H_(2)S` solution ? Also determine `[HS^(-)]` & `[S^(2-)]` Given: For `H_(2)S ,K_(a_(1))=9xx10^(-8),K_(a_(2))=1.2xx10^(-13)`

Explanation

Assuming `K_(a_(1)) lt ltK_(a_(2))`
`{:(,H_(2)S,hArr,H^(+),+,HS^(-),),(t=0,C,,0,,0,),(t=eq,C(1-alpha),,,,Calpha,Calpha):}`
`alpha=sqrt((K_(a_(1)))/(C))=sqrt((9xx10^(-8))/(10^(-2)))=3xx10^(-3)rArr [H^(+)]=Calpha=10^(2-)xx3xx10^(-3)=3xx10^(-5)M`.
`pH=5-log3=4.52`.