Question

Naphthalene, a white solid used to make mothballs, has a vapour pressure of 0.10 mm Hg at `27^(@)C`. Hence `K_(p)` and `K_(c)` for the equilibruim are `: C_(10)Hg(s)hArr C_(10)Hg(g)`
A. 0.10,1.10
B. `0.10,4.1xx10^(-3)`
C. `1.32xx10^(-4)xx10^(-3)`
D. `5.34xx10^(-6),1.32xx10^(-4)`

Answer 1

Correct Answer - C
`C_(10)H_(8)(s)hArr C_(10)H_(8)(g)`
`K_(p)=P_(C_(10)H_(8))=(0.10)/(760)atm`
`=1.315xx10^(-4)atm`
`K_(p)=K_(c)(RT)^(Deltan)`
Here, `R=0.0821 L " atm "K^(-1)moll^(-1),`
`T=27+273=300K`
`Delta n =1-0=1`
`K_(c)=(K_(p))/((RT)^(Deltan))=(1.315xx10^(-4))/((0.0821xx300))`
`=(1.315xx10^(-4))/(8.21xx3)=(131.5xx10^(-6))/(24.63)`
`=5.339xx10^(-6)`