Added the rest of my notes to acid cleaners section

science-of-cleaning.tex

@@ -273,7 +273,7 @@ The square brackets around the \ch{H^+}—that is, \ch{[H^+]}—just mean ``the
 
 \ch{H^+} just means ``a hydrogen atom with an electron removed'' but because hydrogen is just a single proton surrounded by an orbiting electron, this means that it's just a single proton floating around. 
 
-In reality, protons don't do all that well on their own, and tend to bond to water molecules. The actual chemical equation looks like this: 
+In reality, protons don't do all that well on their own, and tend to bond to water molecules, forming what is called a hydronium ion. The actual chemical equation looks like this: 
 
 \begin{center}
 \ch{!(water)( H2O ) + !(hydrogen\ ion)( H+ ) <-> !(hydronium\ ion)( H3O+ )}
@@ -287,6 +287,14 @@ The real question is now ``where do those protons (i.e., hydrogen ions) come fro
 
 Notice the \ch{<=>} arrows in the middle, which indicate equilibrium. That means that this is not a one-way reaction. Instead, some water molecules are always reacting to form hydronium and hydroxide ions, and some hydronium ions and hydroxide ions are always reacting to form water molecules.
 
+Acidic substances (like hydrochloric acid) tend to give up a hydrogen ion (i.e., a proton) readily when dissolved in water, like this: 
+
+\begin{center}
+\ch{HCl + H2O -> H3O+ + Cl-}
+\end{center}
+
+and of course, that hydronium ion can react with water to release a proton, which is where pH enters into it. The more hydronium ions produced, the more protons (i.e., a hydrogen ion) floating around, which means the substance is more acidic.
+
 \chapter{Acid Cleaners}
 
 \section{Acetic Acid (Vinegar)}
@@ -301,7 +309,15 @@ The most common acidic cleaner, and also the cheapest, is good old white vinegar
 
 Most commercial white vinegar available in your local grocery store contains 4-5\% acidity; that is, most of what you are buying is water and only 4-5\% of it is actually acetic acid. Some specialty vinegars like balsamic vinegar may have an acidity level of 6\%. It's okay that these vinegars have such a small amount of acetic acid in them, since they are meant for cooking purposes more than cleaning anything. 
 
-If you head over to the hardware store, you can find ``cleaning vinegar'' which is usually around 30\% acidity.
+If you head over to the hardware store, you can find ``cleaning vinegar'' which is usually around 30\% acidity. You can also buy ``glacial'' acetic acid at your local photography store (it's used as a stop bath when developing photographs), which is the purest form of acetic acid you can buy. 
+
+\section{Citric Acid}
+
+Citric acid is commonly found in citrus fruits (hence the name). You can purchase it as a powder in the canning section of most stores, where it's used to decrease the pH of canned foods to ensure they stay safe when canned.
+
+\section{Hydrochloric Acid}
+
+Hydrochloric acid is pretty strong stuff (and therefore, it's pretty dangerous stuff). It's used in a number of commercially available cleaners, especially those that are meant to clean rust or limescale. You can also buy it in your local building supply center where it probably goes by the name ``muriatic acid''. 
 
 
 \chapter{Alkaline Cleaners}