How to Calculate mEq/L of Ba from BaBr2 Solution?

[cmgbruschi]

Homework Statement

Barium bromide BaBr2 (875.3 mg) was dissolved in water to make one liter of solution. Express the concentration in the following units: mEq/L of Ba.

Homework Equations

Ba has a charge of 2+ which means it has 2 Eq in 1 mole.

The Attempt at a Solution

First I changed the 875.3 mg into .8753 g of BaBr2. The thing that really confuses me is how do I know how many grams of Ba is in .8753 g of BaBr2? I understand how to do this problem if it asked for the mEq/L of BaBr2, but I'm stuck because I can't figure out how many grams of just Ba is in .8753g of BaBr2. Once I figure out the g of Ba I can convert it into moles since there are 137.3 g per mole of Ba.

 

[chemisttree]

Why couldn't you do the same thing for BaBr2? Equivalents don't 'equate' to charge either.

example

H₃PO₄ <-------> 3H⁺ + PO₄^-3

In this example, there are three equivalents of H+ per mole of H₃PO₄ and only one equivalent of PO₄^-3. Notice how the number of equivalents are unrelated to the charge on the ions generated?