Molarity Calculator (Sometimes We Need To Dabble In Chemistry!)
Depending on your research topic, you may need to use a little intermittant chemistry every now and again for your experiments.
Image from rsc.org
Let's say that you know exactly what reaction you need to take place, you have access to the chemicals necessary, and you've thoroughly read the paper outlining the process that tells you all about the stoichiometry. Great! But now comes the more difficult part (if you're not a chemist): how do you know how much of each chemical to weigh out to get the desired amount of solution?
A coworker of mine (and nanomaterial synthesis expert extraordinaire) showed me a quick and easy way to calculate molarity (e.g. the molar concentration) and mass of chemicals necessary for a certain volume of solution. It's the online (and free) Molarity Calculator by GraphPad Software.
All you usually need to know is the molar mass of each of your chemicals (which you can easily look up or calculate) and the desired volume of the resulting solution called for in the experiment. The molarity calculator has four options, and remember that you may need to use different options together to get the final result.
An example: say you know that you need to 1:2 molar ratio of two distinct compounds and you'd like to mix them to make 100 ml of solution in DI water. For simplicity, we set the mass of this first chemical at 1g with a formula weight of 0.5 along with a desired volume of 100 ml in the "Molarity From Mass And Volume" option to calculate the molarity of the solution. Then input this molarity into the "Mass From Volume And Concentration" option along with the fomula weight of 1 (to maintain the 1:2 ratio) and 100ml volume to calculate the mass of the second chemical. Yes, it's just that easy!
