What is the concentration of lead ions and sulfide ions in a saturated solution of lead sulfide (PbS) solution at 25°C?

Apr 11, 2016

1.73 x ${10}^{- 14}$ Mol/liter

Explanation:

PbS (aq) $\iff$ $P {b}^{2 +}$ (aq) + ${S}^{2 -}$ (aq)

${K}_{s p}$ = [ $P {b}^{2 +}$ (aq) ] . [ ${S}^{2 -}$ (aq) ]

On dissociation the number of lead ions and sulfide ion in solution are in equal concentration we can reduce the above equation to ,
[ $P {b}^{2 +}$ (aq) ] = [ ${S}^{2 -}$ (aq) ]

${K}_{s p}$ = [ $P {b}^{2 +}$ (aq) ] . [ ${S}^{2 -}$ (aq) ]

${K}_{s p}$ =  [  Pb^(2+) (aq) ] ^2

[ $P {b}^{2 +}$ (aq) ] = sqrt (K(sp)

[ $P {b}^{2 +}$ (aq) ] = sqrt  3 x ${10}^{- 28}$

$$                               =  1.73 x  10^(-14) Mol/ liter