Chemical reactions are the basis of life on earth. As human beings, we are little more than the naturally abundant elements of which we are composed and the reactions between the compounds that they form. After all, how could life exist without water? Oxygen transport in a body the size of the human body would be impossible without the aid of a complex like hemoglobin. Besides being the basis of many of life's intangibles, chemistry also plays an active role in our daily lives.
Take for instance everyday household cleaning. If you're like me, you like to eat off of clean dishes, prepare food on a clean surface, and use clean restroom facilities. Taking the cleaning of any of these areas into your own hands requires a little chemical knowledge. Have you ever scrubbed away at some grease or oil that just won't come out? That's because we are used to most of the "gunk" that we clean up being a polar substance. Water is also a polar substance, and since like dissolves like, most polar substances dissolve easily in water. However, when we introduce water to big greasy hydrocarbon chains (usually called alkanes, or fats and oils as we know them), the water just slides right over them and our plate stays greasy. This is because fats, oils, and waxes are nonpolar substances. If instead of using water we used less polar mineral spirits (not recommended on food prep items), those greasy alkanes would be dissolved in no time.
Solubility concerns are clearly at the forefront of chemistry in the home. For two substances to be soluble in one another, they must be composed of similar materials, as we saw in the case with water and other polar substances. The interaction between water and nonpolar substances in science is termed the "hydrophobic effect," meaning literally "water fearing." On a cellular level, there are many consequences of this effect, but the same is true in the macroscopic world. For instance, the "greasy" feeling your skin gets when it hasn't been cleaned in some time is due to sebum, a hydrophobic substance your body secretes as a protecting layer. Interestingly, many people wash this layer off in the shower only to replace it with "skin moistening" lotions containing lanolin, which is nothing more than sheep sebum. Another solubility problem occurs when Coke is spilled on the floor, creating a sticky mess that doesn't seem to clean up with any normal household cleaning agents. This is because one of the main ingredients in any soda is phosphoric acid, which is a sticky mess in and of itself, not to mention the sugars and other sticky components found in most sodas. Luckily, phosphoric acid dissolves easily in water, making water (and lots of it) typically the best way to clean up this sort of spill.
Acid/base chemistry also finds its way into our everyday lives. For instance, have you ever touched your car battery only to find that seconds later, you are feeling a tingling or burning sensation? This is because the battery acid is performing a dehydration reaction on your skin. That is, water is being pulled from your tissue in a chemical reaction. Luckily, armed with your knowledge of acid/base chemistry, you quickly sprinkle some baking soda on the offending acid, neutralizing its harmful effects. Or perhaps you've eaten some particularly spicy food or just have a little acid reflux. It's milk to the rescue in these cases. The slightly basic milk will neutralize the slightly acidic foods in no time.
So before you shove those chemistry books into the attic to gather dust, before you decide that there's just no application to a science so complex, think again. Chemistry permeates all of our daily lives whether we think about it every day or not. There is much more to chemistry than the biological reactions occurring inside of us. Chemistry is all around us.