H2S is a toxic gas with rotten egg like smell , is used for the qualitative analysis . If the solubility of H2S in water at STP is 0.195M , calculate Henry's law constant .
1 Kg of solvent contains =
100018=55.55moles
HencethemolefractionofH2Sgasinsolution=
χH2S=nH2SnH2S+nH2O=0.1950.195+55.5=0.19555.745=0.0035
PressureatS.T.P(becausenormallypressureistakenatStandardcondition)=1atm=0.987bar
HencetheformulaforHenry′sconstantis
pH2S=KH×χH2S
HenceKH=0.9870.0035=282bar
Hencethehenry′sconstantis282bar