Marvelous Mixtures Part 1, Sweet Southern Sol

In chemistry matter comes in two very broad categories, pure substances and mixtures. Pure substances are things like pure water, there is only one type of substance (atom or compound) present in any sample. Mixtures are everything else and are often described by whether or not the individual parts can be seen. If a mixture looks the same throughout it is called homogenous (like salt water). If it doesn't it is called heterogeneous (like a salad). I will talk about various kinds of mixtures that cover the whole spectrum at various points. Today we'll deal with a very specific type of homogenous mixture called a sol.

Homogenous mixtures are categorized by how large the pieces of the minor substance is. If the minor compound is an atom or molecule it is called a solution. If it is a little bigger, but small enough that the minor compound cannot be seen by the naked eye it is called a colloid. If it can be seen, it is known as a suspension. The different components can be solid, liquid, or gas and they don't have to be the same as each other. This is how we end up with all of the weird products that seem to be in between phases (like Jell-O). A sol is a very specific type of colloid where a solid is "dissolved" or "suspended" in a liquid. This is all in theory of course. In reality whenever a liquid has particles in it that don't separate out upon standing chemists will call it a solution. If the particles do separate out, it is referred to as a suspension.

Today the weather decided that we should have summer, real DC summer, a little early. We hit 90 degrees Fahrenheit (32 degrees Celsius or 305 Kelvin for those who spend all their time in a lab). So I decided to cool off with some of my sweet tea. A delicious and satisfyingly sweet sol. While the sugar does create a solution, the tea particles are too large for the mixture as a whole to be considered a solution, so a sol it is. And it is a sol that satisfies the soul.

Sweet Tea

Ingredients

4 cups water (plus enough to bring the final product up to a gallon)

3 family sized ice tea bags (or 12 normal sized tea bags)

a pinch of baking soda

1-1/3 cups sugar

Bring 4 cups of water to a boil. Remove from heat. Add a pinch of baking soda and 3 family sized tea bags. Cover and let sit for 15 min. Remove tea bags (you can throw them out at this point). Add sugar and stir until completely dissolved. Pour concentrate into a gallon sized pitcher and fill the rest of the way with water. Chill, pour, and enjoy!