Thinking+and+Communicating+with+Clarity+and+Precision



One of the more confusing concepts I've encountered in chemistry is the Mol and Avagadro's number. Unlike most of the other topics in chemistry, vocabulary was vital here - molar mass, molar number, relative molecular mass, and plain old mass were all different things. It wasn't so much the topics that were confusing, it was the fact that everything was so similar sounding. When you had formulas that stated:


 * n = m / M**
 * d = m / v**
 * c = n / v**

Where **n** equals mols while **m** equals mass and **M** equaled molar mass, it was sometimes hard to get the formula straight, especially since **m** seemed more logical for mols than **n**. What was worse was when I tried to work in a partner, and neither of us was sure which letter meant which - or even what to do with the formula after we knew what it meant. Isabelle and I discussed at length the formulas we needed to use. Eventually we decided that it would be easier for ourselves if we just wrote out the words itself rather than the abbreviations


 * n = m / M >>> mols = mass / molar mass**
 * d = m / v** **>>> density = mass / volume**
 * c = n / v** **>>> concentration = mols / volume**

While the formulas were still a mouthful, it was easier to work with since we wouldn't be tripping over variables that all looked exactly the same. It was a little more to memorize, but I realized that we were able to understand the concept easier when we realized what we were actually plugging in. In problems where we had to flip the formula around, like solving for mass given molar mass and mols, for example, it is much easier to have the word formula rather than the abstract formula to look at. A concrete, worded formula sticks in my head more easily than a few letters.

