(Part 4 of 4 - Photography Contest Entries)
Let us know which of these pictures from the ChemClub Photography Contest are your favorites. The photo with the most likes, comments, etc. will be the ChemClub Choice Award winner!
Stories of Chemistry
For the stories of chemistry category, students were to communicate chemistry in a photojournalistic style using a series of photos with a story about the photo’s relationship to chemistry.
Titration is a common laboratory method of quantitative chemical analysis that is used to determine the unknown concentration of a known reactant. Because volume measurements play a key role in titration, it is also known as volumetric analysis. A reagent, called the titrant or titrator, of a known concentration (a standard solution) and volume is used to react with a solution of the analye or titrnad, whose concentration is not known. Using a calibrated burette or chemistry pipetting syringe to add the titrant, it is possible to determine the exact amount that has been consumed when the endpoint is reached. The endpoint is the point at which the titration is complete, as determined by an indicator. This is ideally the same volume as the equivalence point – the volume of added titrant at which the number of moles of titrant is equal to the number of moles of analyte, or some multiple thereof. In the classic strong acid-strong base titration, the endpoint of a titration is the point at which the pH of the reactant is just about equal to 7, and often when the solution takes on a persisting solid color as in the pink of phenolphthalein indicator.