Hey there!
We Know that:
2 Ag⁺(aq) + Zn(s) <-> Zn²⁺(aq)+2 Ag(s)
The equilibrium expression for the reaction is:
Kc = [ Zn⁺² ] / [Ag⁺ ]²
Hope that helps!
Explanation:
As the total concentration is given as 1.2 mM. And, it is also given that salt present in the solution is NaCl.
As sodium chloride is an ionic compound so, when it is added to water then it will dissociate into sodium and chlorine ions as follows.

So, it means in total there will be formation of 2 ions when one molecules of NaCl dissociates.
Therefore, concentration of chlorine ions will be calculated as follows.
Concentration of
ions =
= 0.6 mM
Thus, we can conclude that the concentration of chloride ions is 0.6 mM.
The molar mass of sulfur is 32 g/mol.
The mass of 6.3 moles of Sulfur is 32×6.3=201.6 grams
<span>♡♡Hope I helped!!! :)♡♡
</span>