A 100.0 mL solution made from dissolving 0.2515g of a powdered drink was determined to have a molarity of blue dye of 2.0 x 10-6 M. If the molar mass of the dye was 792.84g/mol, what is the percent dye in the drink?
[Dye] = Moles Dye / Volume = Mass Dye/ (Molar Mass x Volume)
Mass Dye = [Dye] x Molar Mass x Volume
% Dye = (Mass Dye / Mass drink ) x 100
% Dye = [Dye] x Molar Mass x Volume x 100/Mass Drink
% Dye = 2.0 x 10-6 x 792.84 x 0.10000 x 100 / 0.2515 = 0.06 %
(0.06305 with more sig. figs.)