The lithium ion[Li⁺]=1.642 M
Further explanation
Ionic compounds will dissociate into ions when dissolved in water. The strength of the dissociation depends on the strength of the electrolyte properties. The stronger it is, the more ions will dissociate
Reaction
Li₂S⇒2Li⁺+S²⁻
mol ratio Li₂S : Li⁺: S²⁻ = 1 : 2 : 1
so the lithium-ion (Li⁺) concentration :
[tex]\tt 2\times 0.821=1.642~M[/tex]
