Question 809155
Find the formula weight for {{{CuCl[2]}}}.
{{{63.546+2*(35.45)=134.446}}} grams per mole.


The rest is just units conversions:
{{{0.25M = 0.25*(134.446)*(1/1000)}}} {{{(moles/liter)(gram/mole)(liter/mililiters)}}}
That is the concentration in grams {{{CuCl[2]}}} per mililiter of solution.


Key idea is (concentration)*(volume)=(quantity), assuming numerator of "concentration" is is the same unit as "quantity".


{{{c*v=12}}}
{{{v=12/c}}}
You want {{{highlight(v=12.0/(0.25*(134.446)*(1/1000)))}}} mililiters