#20: Synthesizing Salt (Part 1)

I recently conducted another simple, yet fascinating chemical reaction. In doing so, I relied on two chemicals: hydrochloric acid (HCl) and sodium hydroxide (NaOH). Dilute hydrochloric acid, often called muriatic acid, is commonly sold as a powerful cleaning agent. Even in low concentrations it has the ability to strip cement as well dissolve most metals. In higher concentrations it represents a scary, yet useful lab chemical. Similarly, sodium hydroxide, also known as lye, has a variety of uses. As you might know, lye is an important component of soap, although its concentration is usually quite low. In its pure form, sodium hydroxide can destroy most metals as well as glass. Essentially, both hydrochloric acid and sodium hydroxide are extremely corrosive substances. So what dangerous purpose would I be using them for? Well, you'll see soon enough.

To start, I did some calculations to figure out how much of each substance I would need. I then weighed out granules of white sodium hydroxide and added them to a glass jar. I used a jelly jar so as not to harm one of my precious beakers. Next, I measured out my hydrochloric acid using a graduated cylinder. With my camera ready and at a good distance away, I poured the acid into the jar. As the chemicals reacted, they began to froth and boil. However, after about ten seconds, the mixture calmed down. The reaction's exothermic nature had caused the jar to become quite hot. The resulting product was a clear-white solution with a syrupy consistency. The question was, what was it chemically?

Considering the destructive nature of the chemicals used, you might expect this new concoction to dissolve diamonds. Yet, the two substances that I had synthesized were far more sinister. Behold sodium chloride (NaCl) and dihydrogen monoxide (H2O)! Wait what? Table salt and water? Yep, here's the chemical equation to prove it: HCl + NaOH → NaCl + H2O. See how that works?

This simple reaction represents a fundamental area of chemistry. As is implied, hydrochloric acid is an acid. Sodium hydroxide on the other hand is a base. As I pointed out before, both can be extremely corrosive. However, they operate in completely different ways. In other words, they represent opposite ends of the spectrum. In fact, they sit on opposing sides of the pH scale. At the same time, acids and bases are sort of like chemical counterparts. When they come together, they neutralize each other. And, in the majority of cases, they are converted into salt and water. It is important to keep in mind that salt is a general term for any ionic compound that is formed by the reaction of an acid and a base. However, in this reaction, the resulting salt is the same one that you put on your french fries. In summary, I was able to take two chemicals, both of which can dissolve metal, and transform them into nothing but simple salt water.

In order to make sure the solution was truly neutral, I tested it with litmus paper and adjusted it accordingly.  

To learn more about the concept of acid/base neutralization...

http://en.wikipedia.org/wiki/Neutralization_(chemistry)