Applications

The most common application of acid-base chemistry is in titrations. The video gives a glimpse of the process and offers a situation when you want to use the process of titration.

After watching the video, we have learned:

• Titrations are useful in determining the molarity (moles of solute per liter of solution) and the video even goes through the calculations that give the molarity of the unknown solution by using titration data.

• Titrants are known solutions--that is to say, chemists know what is in the solution as well as the molarity of the solution--that are added to the buret.

• The titrant is added drop-wise from the buret into a known amount of analyte (unknown solution)

• Acid-base indicators tell when a solution changes from acidic to basic. An example is phenolphthalein , which is colorless in an acidic solution but pink in a basic one.

If you want to learn more about acid-base indicators, here are a few resources:

• https://chem.libretexts.org/Bookshelves/Physical_and_Theoretical_Chemistry_Textbook_Maps/Supplemental_Modules_(Physical_and_Theoretical_Chemistry)/Acids_and_Bases/Acid_and_Base_Indicators/Acid_and_Base_Indicators

• https://www.ch.ic.ac.uk/vchemlib/course/indi/indicator.html

• https://courses.lumenlearning.com/introchem/chapter/acid-base-indicators/

But acid-base chemistry is not limited to titrations! Doug Johnson describes in his article "Uses of Acids & Bases" more ways we see acid-base chemistry. Here are a few Johnson describes:

• Weaker acids/bases can be used in everyday products like cleaners. However, the further the acid/base gets from a pH of 7, the more likely it is to be used in research or industrial capacities.

• Vinegar (acid) is used to kill germs, deodorize, and remove rust

• Bleach (sodium hypochlorite, NaOCl, a base) is used as a cleaning agent in laundry, as an oven cleaner, or as a sink declogger. Bleach is also a component in producing explosives---so be careful with those household cleaners!

• Calcium carbonate (CaCO3), found in anti-acids like Tums, is used to reduce heartburn by neutralizing stomach acids.

• Sulfuric acid (H2SO4) is an industrial precursor for phosphoric acid (H3PO4), which is used in detergents and phosphate fertilizers. Sulfuric acid is also involved in rain acidification.

• Nitric acid (HNO3) is used in fertilizers and explosives.

• HCl is used to clean metal sheets in the steel industry.

• Sodium hydroxide (NaOH) is used to remove lignin from paper pulp in the paper industry. NaOH (as lye) is also a chemical peeling agent for fruits.

• And of course, acids and bases are used as laboratory reagents. As an example, HCl is used to make ClO2 (chlorine dioxide) and NH4Cl (ammonium chloride).