Titrations, pH, and our funky fish tank

If the fish in our office tank could talk, they’d probably be saying “the struggle is real” right now. There’s apparently a problem with the pH in our really cool retro TV fish tank and it’s killing our fish. Our office manager has purchased supplies to adjust the pH in the tank and some of the fish are hanging in there, but at this point things could really go either way for the survivors. We share this tragic tale not to garner sympathy, but to illustrate the importance of pH.

Measuring pH to determine the acidity or basic qualities of a liquid has implications far beyond Fish Tank, Titrations, PHwhether or not your pool is safe to swim in or if you’ll find your goldfish belly up tomorrow morning. It’s also a valuable property pertaining to polymer chemistry.

The “H” in pH refers to the amount of free hydrogen and hydroxyl ions in a liquid (typically water). When the liquid has a higher concentration of free hydrogen ions, it gets a score of less than 7 on the pH testing scale, meaning it’s considered acidic. Liquid with more hydroxyl ions will score greater than 7 points, indicating the liquid is basic. The pH of a liquid affects its solubility — and how different elements introduced into the liquid react with each other. In the case of our fish tank, the pH determines whether or not our fish can survive in the water. Something’s out of balance in their eco-system, and until we restore that balance — and re-establish a “buffer” — the fish will struggle.

Scientists test for pH in many ways. Some are low-tech, like the color-changing paper strips you use to test for pH in high school science lab. We actually use those in our labs. Other tests are more sophisticated, and we do those, too — including the use of electrode detectors. When dipped into a solution, the electrode changes potential based on the ionic content of the solution. By reading this potential, you can determine the pH. The electrode test produces a more refined result since it can measure to two decimal places, whereas the test strips can read only to the nearest single unit.

Funky Fish Tank
Our Funky Fish Tank

Titration is another way to test for pH. Basically, the tester starts with a solution he or she already knows the concentration of. The tester then uses that knowledge to determine the concentration of an unknown solution. How the two solutions react and when the reaction is complete tells us a lot about what’s in each solution. When doing an acid-based titration, the tester monitors the pH as he or she adds individual portions of acid. If you start with pure water and add base or acid, it’s a very simple system while you adjust the pH. If you’re neutralizing acid or base, it’s more complicated. When you’ve achieved equilibrium where both solutions are equal, you’ll see a significant change in the pH.

Measuring pH during polymer testing can help us determine how much of a given chemical exists in a sample, determine the presence and quantity of isocyonates (the raw materials of polyeurethane), and act as a measure of quality assurance. pH testing plays a vital role in many of the services Polymer Solutions provides our clients, and we’re experts in understanding how to use this measure to gather the information our clients need.

Hopefully, we can use our pH knowledge to help save our goldfish!