CHEMISTRY COMMUNITY

How would you find the mass of a compound that is needed to get a certain molarity (when given the molarity and volume)?

First you take molarity and multiply it by liters. Then you that the value in mols that you are left with and multiply that by grams/mole. Finally you are left with grams.

More specifically, take the volume you would like to prepare and multiply that by molarity (moles/liters) which should give you moles. Once you have moles, multiply by the molar mass of the compound (found from adding up the atomic masses). This gives you grams needed to create the solution.

If you need more clarity or an example of this, I found a good link that works through a question pertaining to NaCl (below).

http://dl.clackamas.edu/ch105-04/calculat.htm

Scroll about halfway down to see how they found mass from molarity and volume.