Question

White solid balls of naphthalene `(C_(10)H_(8))` used as moth balls were kept in a closed container at room temperature `(27^(@)C)` . The vapour pressure above the balls was found to be 0.10 mm Hg. The value of `K_(c)` for the sublimation equilibrium ,
` C_(10)H_(8) (s) hArr C_(10)H_(8) (v) ` is
A. ` 1*32 xx 10^(-4)`
B. ` 5*36 xx 10^(-6)`
C. ` 3*4 xx 10^(-7)`
D. ` 0*10`

Answer 1

Correct Answer - B
` K_(p) = p_(C_(10)H_(g)= )0*10 " mm"`
` = (0*10)/760 " atm" = 1*32 xx 10^(-4) "atm " `
` C_(10)H_(8) (s) hArr C_(10) H_(g) (g) , Delta n = 1 `
` K_(c) = (K_(p))/(RT)^(Delta n)= (K_(p))/(RT) = (1*32 xx 10^(-4))/(0*0821 xx 300) `
`= 5*36 xx 10^(-6)`