Stoichiometry. It has brought many General Chemistry students to tears. Like so many students, I struggled with this concept when it was first introduced to me in my sophomore year of high school. Through my learning experiences, I will hopefully help you understand the method behind the madness of this somewhat complex word. Simply put, stoichiometry is a concept in Chemistry that describes the amounts of substances, either reactants or products, in a given reaction. It’s based on the Law of Conservation of Mass….mass is neither created nor destroyed. Using stoichiometry you can determine the amount of product produced during a chemical reaction using a coefficient ratio of reactant to product. It sounds complicated, right? It can be, but if you have read my other posts and have mastered balancing chemical equations, then you will easily see the direct correlation between balancing equations and stoichiometry. In order to be successful at stoichiometry, you must have an average understanding of the fundamentals of balancing chemical equations. So, if you have supreme confidence in your balancing capabilities, let’s get started with my tips on understanding STOICHIOMETRY!
1.) Know the Terminology
If you’re going to succeed with the mathematical calculations involved in stoichiometry, make it a point to familiarize yourself with basic terminology and various phrases used to describe a chemical reaction. Know chemical equation, mass of reactants, mass of products, molecular weight, molar mass, formula, mole, Avagadro’s number, coefficient, standard unit (mg, g, kg, ect.), conversion factor, yield, molecule, element, and atom. By understanding these terms you will optimize your knowledge of stoichiometric calculations. Know the terminology the lecturer is using and stoichiometry will be more enjoyable.
2.) Know Your Algebra Rules
ALGEBRA! I had that years….I mean decades ago. Who needs Algebra? Every single General Chemistry student. Algebra rules are the core of stoichiometric calculations. Know the rules of exponentials, cross-canceling, cross-multiplying, parentheses, scientific notation, and most importantly significant figures. This tip is fairly straight forward….familiarize and remind yourself of the forgotten Algebra rules. Understanding, performing, and applying the mentioned mathematical operations will make stoichiometry a breeze!
3.) Stay Organized
Performing any calculations requires a logical thought process. But, when doing stoichiometry it is extremely important to keep your calculations organized in a step-by-step format. Stoichiometric calculations usually require several step before arriving at a solution. Write down each individual step in the calculation. If 2+2=4 is a step, write it down. Do not do multiple steps in your head and expect to remember them later. Calculations, especially those involving chemical equations, can get very complex. Staying organized and allowing yourself to see the visual logic of a given calculation will enable you to recognize any mistakes before arriving at an incorrect solution. Take the extra couple minutes and go the extra mile….write down every step.
4.) Units, Units, Units
UNITS. DO NOT forget your units when trying to complete a stoichiometric calculation! Forgetting units while solving a given equation will result in many hours of mind-boggling wrong answers. Remembering units and staying organized compliment each other in stoichiometry. A written step-by-step thought process allows you to include units for each and every number (where applicable) in a calculation. This simple tip will make your entire Chemistry career SO MUCH easier. One final word….UNITS!
Are you ready to tackle stoichiometry? Follow my tried and true tips and stoichiometry will become easier as your General Chemistry course progresses. Preparation and organization are vital in any Chemistry course, but are especially evident in stoichiometry.
Try the given tips mentioned in this post….they worked for me! If you have time, read my other posts covering the basics of a General Chemistry course. Did you find this post helpful? Let me know by leaving a comment. Keep me updated on your Chemistry success. Check back often because I’m always trying to simplify General Chemistry. Thank you and take care! GOOD LUCK!