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. 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 drum. What mass of EDTA would need to be added to each drum to completely complexes all of the calcium in the barrel?

There should be added 24.33g of EDTA

Explanation:

EDTA + Ca2 + → Ca (EDTA)

MM of EDTA = 292.24g/mole

MM of Ca2 + = 40g/mole

An aqueos waste contains 20 mg/L Calcium, and collects the waste in 44 gallon drums.

The concentration of Ca2 + ions = 20mg/L = 0.02g/L

We know 1 gallon = 3.785L

The mass of calcium ions is in 44 gallons

⇒44 gallons = 3.785 * 44 = 166.54 L

Since the aqueous waste contains 0.02g/L calcium

in 44 gallons or 166.54 L ⇒ 166.54 * 0.02g = 3.308g

MM of Ca2 + = 40g/mole

⇒40g of Ca2 + reacts with 292.24g of EDTA

⇒ (292.24/40) * 3.308g = 24.33 g

There should be added 24.33g of EDTA