[PaulR]

Hello everyone, first time on this forum. I was testing the sulphate conc. in a river water sample following EPA 375.3. At the end of the method there was a formula to calculate the sulphate conc. :
mg/L SO₄ = (mg BaSO₄ x 411.5) / mL sample

Where does the 411.5 come from?

[Borek]

Why does it matter?

But it is a pretty simple conversion using molar masses and mL to L.

[PaulR]

Thanks for the reply. I was just curious as to where it came from because it didn't have any units.

[Borek]

It has units, they are just not shown.

But they won't be helpful, as they would be mL/L (or reciprocal of that).

[PaulR]

Oooh ok, thanks again.