March 1, 2012 (Vol. 32, No. 5)
Strong Points: Unique acid/base calculator
Weak Points: Limited chemical list
This aptly named app by Sigma-Aldrich provides researchers with an easy-to-use tool to calculate—yep, you guessed it—molarity! More specifically, the app tells users how to make solutions of a particular molarity. Under the “molarity” tab, users enter the formula weight, desired final volume, and desired concentration. In exchange, the app returns the mass of the chemical that must be weighed out and added to make the chemical concoction. The “stock dilution” tab houses a similar tool, except this time users enter stock concentration, desired final volume, and desired concentration to determine the volume of the stock solution that must be added. A third tab named “acid and base” is what really sets this app apart from other molarity/dilution calculators. With this tool, users select an acid/base from a predefined list and the app autopopulates density, formula weight, and weight percentage based on commonly sold stock solutions. The app then provides detailed instructions on how to make a solution of the desired volume and concentration.