How do I calculate concentartion?

This should point you in the right direction.

concentration con‧cen‧tra‧tion  /ˌkɒnsənˈtreɪʃən/ Pronunciation Key - Show Spelled Pronunciation[kon-suhn-trey-shuhn] :
6. Chemistry. (in a solution) a measure of the amount of dissolved substance contained per unit of volume.

Thank you for posting your question to the Ask Me Help Desk.

In chemistry, concentration is oftentimes given in molarity. (abbreviated M)

Molarity refers to the number of moles of solute per liter of solution. For example, if I have 1 liter of a solution that contains 2.5 moles of a substance dissolved in it, it would be a 2.5 molar solution or 2.5 M.

Molarity = moles of solute ÷ liters of solution

Remember that the solute is the substance that gets dissolved and solution is both the solute and solvent together.

To calculate this you need to make sure that you are dealing with the correct units.

For example, say you are given the following information...


35 g of NaCl are dissolved in enough water to create 750 mL liters of solution. What is the concentration?

You first have to convert the grams NaCl to moles NaCl and the mL to L.

This would be 0.5989 mol NaCl and 0.750 L

By dividing moles by liters we get a concentration of 0.7985 M.

its simply the amount of moles of a substance per volume of solvent. In my country, the volume of the solvent is dm^3 though compared to rudi_in which is in litres. Therefore you just have to work out the number moles of the solute divided by the volume of the solvent. I hope this was helpful. If you need examples, there are already one above (and a copy! )

Oh I almost forgot. You can find answers to your question by having a look completely down the window "similar asked questions".