**Practice Problem 3**

At 25^{o}C, a saturated solution of chlorine in water
can be prepared by dissolving 5.77 grams of Cl_{2} gas in
enough water to give a liter of solution. Calculate the molarity
of this solution.

**Solution**

The key to solving this problem is recognizing that we need to know the number of moles of solute in a solution and the volume of the solution before we can calculate the molarity of the solution. The number of moles of solute in this solution is easy to obtain.

We now know the number of moles of solute (0.0814 mol Cl_{2})
and the volume of the solution (one liter). The concentration of
Cl_{2} in this solution is therefore 0.0814 moles per
liter, or 0.0814 *molar*.

0.0814 mol Cl_{2} |
= | 0.0814 M |

1 L |