General Chemistry (The contents will be updated periodically)

General Chemistry could be quite challenging for some students who have no chemistry background or a little chemistry background. Even if students took some AP chemistry before, they could still get confused with some concepts. I hope the following information could help students go through those difficult times. Please note that I constantly updating the contents and if you find some errors, please let me know.

• Q1: What should you know about molecular formulas? In chemistry, you will inevitably work with molecular formulas quite often. Therefore, it is important to know what is a molecular formula and what information you get from a molecular formula. Here I listed at least 7 things you can get from it. (a) the formula tells you...read more


• Q2: What should you know about atoms? Atoms are the building blocks of molecules. Atoms interact with each other to form a variety of molecules, which show different chemical and physical properties. Here I will use the carbon atom as an example to show some important concepts (not all) you should know. Keep in mind that we use a symbol to represent each atom (strictly speaking, it should be an element)... read more


• Q3: What should you know about dimensional analysis? In chemistry, we do dimensional analysis quite often, therefore, it is important to learn some skills so that you can complete tasks quickly and accurately. First of all, a conversion factor is the equivalent of two quantities expressed in a fraction. For example... read more


• Q4: How to balance a chemical equation balancing a chemical equation sometiems could become quite challenging. Sometimes, an equation can be easily balanced by observing the number of elements on both sides; but most times, we need to do it systematically, I will show several examples to demonstrate this principles, for example.... read more


• Q5: How to determine the limiting reactant Sometimes we add two or more reactants together to react. In most cases, one or two will not be consumed, which comes to a question about which one or ones are left, which one is consumed and how much of the product is being produced. All are related to the limiting reactant. I will show several examples to demonstrate a general strategy to answer these questions.... read more