Learn about Senior Chemistry, Acids and Bases 1, in this comprehensive video by bannanaiscool.
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Rob Lederer: Before we get into talking specifically about the properties and definitions of acids and bases, let's make sure we understand the properties of all solutions, and that includes another two different types of solutions. One of them is molecular. Now a molecular remember, is where you get non-metals coming together and when they bond together, they form compounds that when you dissolving into water, if you can dissolve them into water, they're going to be non-electrolytes. Now what does that mean? A non-electrolyte means you don't conduct an electrical current. So if you stir a molecular substance into water and then you test its conductivity, you'll find that it won't conduct. Water is molecular too, although water is kind of special, because it does ionize a little bit, so it conducts to an extremely little percent, but it sort of does. So here is the thing about molecular solutions though. If a molecule does dissolve, if it's polar, remember that, because water is polar too, like it dissolves. Then it will have a pH of 7. So if you have a colorless solution of a pH of 7, you can tell if it's an ionic type of solution or molecular just based on those two properties, but the electrolyte part, now that's the diagnostic feature, which means that, that's an exclusive property to molecular solutions, they are non-electrolytes. If you get something that doesn't conduct, it's molecular. Some of the examples are things like, well here is sucrose and glucose and maybe even C2H5OH, not even, that's for sure, that's ethanol. Ethanol, drinking alcohol does not conduct current and either does something like methanol, something you wouldn't drink because that's wood alcohol, that's the gas line anti-freeze. So molecular solutions, non-electrolytes, very important. Some solutions that also have a pH of 7 but are different in molecular are neutral ionic solutions and those solutions conduct electricity because they are ionic compounds, and when they hit water, they breakdown into ions, charge particles that allow a current of electrons to passthrough. So there are electrolytes, which means that they conduct electricity but the pH is still 7. So if you got a pH 7 solution, it might be neutral ionic or molecular, it can be an acid or a base. They are also be colorless but sometimes have a little bit of color, some ionic compounds can have that, but here are some examples that are very important to recognize a kind of trend in. so sodium chloride, potassium iodide, calcium nitrate, lithium bromide, examples of neutral ionic compounds, but it's the negative ions that really make them neutral; Br, NO3-negative, I-negative, Cl- negative. You're going to see pretty soon when I put up a list of strong acids that all of these irons are the conjugate basis to a strong acid, which means you just take the H off of an acid and what you have left? That iron by itself in solution or attached to usually group 1 or 2a elements, they are neutral in nature; they are the ones that have a pH itself, the conjugate basis of strong acids.