What is Titration?

What is Titration?

Titration is a common laboratory method of quantitative chemical analysis, used to determine the unknown concentration of the titrand. This article explains this concept and the information related to it.
Titration is basically a process which is used to calculate the property (molarity) of one solution (say acid or base) to infer an unknown property of another solution. The details are further elaborated in the following paragraphs.

Definition

Titration is one of the experimental methods used in chemistry classrooms and practical laboratories, where the solution of a known concentration is catered to influence the other unknown solution. In acid-base chemistry, it is employed just to determine the pH value of a particular solution. Most of the time, the determining solutions result into a base property, which means it has a pH value extending 7. Usually, the case is opposite for an unknown solution. It is an acid having a pH value below 7. Any general titration process functions in a definite way. That is, the acid solution is added to the base solution to obtain a neutral pH value 7. Until the solution reaches a pH value of 7, the adding of acid continues. Once the pH indicator shows a color change, that's the hint for us to know that the solution has reached the desired pH value (7). The acid-base titration is used to find the percent purity of chemical elements, and is generally done with aqueous solutions of the compounds.

Procedure

The process of titration is simple; the apparatus contains a flask of unknown solution, called titrand, whereas the known concentration solution, called the titrant, is reserved in a burette just above it. A burette is a vertically suspended, calibrated tube with a stopcock right at the bottom of it. This helps in regulating the flow of the fluid (titrant) into the flask below. In the acid-base titration, as the fluid flows into the flask, the pH indicator (phenolphthalein) changes its color to pink. In some other cases, the color evolved is methyl orange. Once the color change in the indicator is observed, understand that the process has ended. The volume of the resultant would be same as the equivalence point, or the volume of the added titrant. There will be a point in the experiment where the chemical agents and the reactants are going to neutralize each other. This is the time when you will have to read the scale on the burette, and measure the volume of the reagent. Once the reagent concentration is measured, the reactant mole calculations can be done using the molarity formula:

Molarity = number of moles รท volume (L).

Back Titration

At times, the standard titration method is not useful enough. The reaction can be too slow between the reactants and the titrant, or there can be an issue with some end point results. In such cases, the technique of back titration comes handy. There are two reagents in this technique, one which reacts with the original substance, and the other one which reacts with the first reagent. This process is used if the endpoint of a back titration is easier to determine than that of a normal titration.

Uses
  • Acid Rain
  • Nutrition
  • Blood Sugar Testing
  • Aquarium Water Testing
  • Wine
  • Wastewater Analysis
  • Pregnancy Testing
Titration isn't solely used in high-school chemistry labs, but it's employed in many other fields like science industries, and medicines too.