As you would almost certainly predict, especially if you’ve ever inadvertently taken a mouthful of water while swimming in the ocean, this ionic compound dissolves readily in water. The first substance is table salt, or sodium chloride. Imagine that you have a flask filled with water, and a selection of substances that you will test to see how well they dissolve in the water. Let’s revisit this old rule, and put our knowledge of covalent and noncovalent bonding to work. You probably remember the rule you learned in general chemistry regarding solubility: ‘like dissolves like’ (and even before you took any chemistry at all, you probably observed at some point in your life that oil does not mix with water). It is critical for any organic chemist to understand the factors which are involved in the solubility of different molecules in different solvents. In organic reactions that occur in the cytosolic region of a cell, the solvent is of course water. In recent years, much effort has been made to adapt reaction conditions to allow for the use of ‘greener’ (in other words, more environmentally friendly) solvents such as water or ethanol, which are polar and capable of hydrogen bonding. In the organic laboratory, reactions are often run in nonpolar or slightly polar solvents such as toluene (methylbenzene), hexane, dichloromethane, or diethylether. Virtually all of the organic chemistry that you will see in this course takes place in the solution phase.