# If 500ml of Lanthnum Chloride solution is enough to remove 1ppm PO4 from 1000L of water, what effect would a dosage of 166ml have on a volume of 30L?

##### 1 Answer

That respective dosage would remove **0.01 ppm** phosphate anions**30 L** of water.

The are a couple of ways of solving this problem, but the easiest way I can think of is by using two simple conversion factors.

You know that **500 mL** of lanthanum (III) chloride will remove **1 ppm** from **1000 L** of water. The first conversion factor you'll use will determine how much phosphate anions will be removed by **166 mL** of lanthanum (III) chloride in *1000 L* of water.

If you were to add **166 mL** of lanthanum (III) chloride to *1000 L* of water, that's how much phosphate anions you'd remove. Now you need to see how much you'd remove from **30 L** of water

Rounded to one sig fig, the answer will be