anions in solution will combine with the silver cations to produce bright white silver chloride precipitate.

Suppose an EPA chemist tests a $250.mL$ sample of groundwater known to be contaminated with copper$($II$)$ chloride, which would react with silver nitrate solution like this:

$CuC{l}_2(aq)+2AgN{O}_3(aq)2$AgCl$(s)+Cu(N{O}_3{)}_2(aq)$

has collected $5\mathrm{.}8mg$ of silver chloride.

Calculate the concentration of copper$($II$)$ chloride contaminant in the original groundwater sample. Round your answer to $2$ significant digits.