Question

If the value of K_sp for Hg₂Cl₂ (s) is X then the value of X will be ____ where pX = - log X.
Given:

\[\ce{Hg2Cl2 + 2e- -> 2Hg(l) + 2Cl-}\],  E° = 0.27 V

\[\ce{Hg+2 + 2e- -> 2Hg(l)}\]   E° = 0.81 V

Options

• 8

• 2

• 6

• 0

Answer 1

If the value of K_sp for Hg₂Cl₂ (s) is X then the value of X will be 6 where pX = - log X.

Explanation:

`"E"°_("Cl"°//"Hg"_2"Cl"_2//"Hg") = "E"°_("Hg"_2^(2+)//"Hg") + 0.059/2 log "K"_"sp" ("Hg"_2"Cl"_2)`

0.27 = `0.81 + 0.06/2 log "K"_"sp"`

`0.06/2 log "K"_"sp" ("Hg"_2"Cl"_2)` = - 0.54

log K_sp (Hg₂Cl₂) = - 18

X = log K_sp (Hg₂Cl₂) = 10^-18

- log X = - log K_sp (Hg₂Cl₂) = 18

`"pX"/3 = - 1/3 log X = 18/3 = 6`