This session the student and I began by reviewing the material that we went over last time: gas laws and energy of chemical reactions. Then we moved on to new material, which involved covering the book that we purchased from Chapter four onward, which included material that she had seen in her class but only was exposed to a fraction of what is required by this subject test.
The first large topic that we went over was hybridization. This is the process of determining the shape of the electron clouds which are involved in covalent bonding. There are four main types: sp, sp2, sp3, sp3d2 The s orbital contains only one pair of electrons, whereas the p orbital can contain 6 electrons, and the d orbital contains 10.
The next large topic we went over was nomenclature. We learned how to name salts as well as nonpolar molecules and acids and bases. This was detailed in the notes. However, one thing that was worth talking about in this topic was oxidation numbers and the oxidation numbers of polyatomic ions. I told the student that she should learn these via the use of flashcards in order to memorize the oxidation numbers of them so she is able to accurately predict the compositions of salts and some covalently bonded molecules.
The next very large topic that we went over was acids and bases and their relationship to solubility. We had talked about solubility briefly in the last class, but now we discussed it more in depth. We discussed how things get dissolved, and reviewed the definition of a salt. We then talked about polar vs nonpolar solvents. We reviewed that a detergent is a molecule which is both polar (at one end) and nonpolar (at the other end). In this way it is able to dissolve nonpolar things while also being washed away by the polar water molecule. We continued by relating the idea of solubility to acids and bases. We said that an acid in its solid form isn't really an acid. It's not until the acid is dissolved in water that it becomes dangerous. This is because all acids dissociate in water to form a negative ion and also a proton. Bases dissociate in water to form a positive ion and a negatively charged hydroxide ion. The acids donate their proton to whatever they touch which ends up forcing a reaction. The bases demand a proton of whatever they touch and then force a reaction. In this way, acids and bases deal with the flow of protons, where chemical bonding focuses on the flow of electrons. The only topic that covers both is radioactivity. We reviewed that when a proton and a hydroxide ion react, they form water, and we then defined the pH scale. We finished our explanation of acids and bases, which brought us to be able to do a portion of a practice section. We practiced naming molecules (with the nomenclature from earlier) and also practiced the nature of how acids and bases combine. This brought us to the end of the session."