[vanalm]

I don't even know where to begin with this one. There is nothing like this in my book.

A 0.8595 g. sample of an unknown compound was found to contain 59.8% Pb ²⁺. If a 0.1000 M K₂CrO₄ solution was used to completely precipitate the Pb²⁺ ion as PbCrO₄, what volume in ml. of K₂CrO₄ was needed?

[AWK]

1 .Calculate mass of Pb in sample, change mass to moles.
Write down a balanced reaction. According this stoichiometry moles Pb = volume K2CrO4(in liters) times concentration of K2CrO4