1. The problem statement, all variables and given/known data Ethylene diamine tetra-acetic acid (EDTA) is a water-soluble compound that readily combines with metals, such as calcium, magnesium, and iron. The molecular formula for EDTA is C10N2O8H16. Assume one EDTA molecule complexes (associates with) one metal atom. A factory produces an aqueous waste that contains 20 mg/L calcium and collects the waste in 44-gallon drums. What mass of EDTA would be need to be added to each drum to completely complex all of the calcium in the barrel. 2. Relevant equations 3. The attempt at a solution I'm really not sure how to go about this one, i started off trying a few things but it ended up at a dead end....here's what I got so far: 0.02 g/L * 1 mol Ca / 40.078 g Ca * X mol EDTA / 1 mol Ca * 294.24 g EDTA / 1 mol EDTA I realized this wasn't getting me any closer to an answer so that's why I'm asking for any help you guys can offer.