chemistry
posted by cheri .
What volume of 0.402MK3PO4 is required to
react with 43 mL of 0.507 M MgCl2 according
to the equation
2K3PO4 + 3MgCl2 ! Mg3(PO4)2 + 6KCl
Answer in units of mL

The arrow is made this way > or this way ==> or this way >>.
This is a regular stoichiometry problem which I've worked for you before. Here is a site that explains how to do them.
After you find mol K3PO4 required, use M = mols/L. You knopw mols from the solution just done and you know M, solve for volume in L and convert to mL.
chemistry.about.com/od/workedchemistryproblems/a/IdealGasVsNonIdealGasExampleProblem.htm