Recording-2026-03-23T23:04:38.019Z

Material Coverage: Everything discussed in the previous lectures and today will NOT be on exam two, but will appear on exam three.
Equation Sheet: An announcement was made that the equation sheet is now posted. Students are encouraged to refer to it for exam preparation.
Exam Format: The format will be similar to the previous exam, containing multiple choice and fill-in-the-blank questions.

Titrations:
- Focus on solubility, equilibria, and titrations, especially basic equilibria that were initially discussed.
- Polyprotic acids will also be included in these discussions.
Quiz Four: Reminders given for students to check if they have completed Quiz Four.

Chelating Titration (Complexometric Titration):
- Introduction to a new type of titration called chelating titration or complexometric titration.
- Chelating Agents:
- Commonly known in the medical field for treating metal poisoning (e.g., lead poisoning).
- Example: EDTA (Ethylenediaminetetraacetic acid) is often administered to bind with metals and aid in their excretion from the body.
Metals in Titration:
- Metals are classified as Lewis acids and can accept electrons due to their available orbitals.
- Most metals relevant for these types of titrations are found in the third row or higher of the periodic table, available to bond due to empty orbitals and valence electrons.
Ligands:
- Ligands are molecules that bond to metal ions donating electrons.
- Metals often exhibit a hybridization of sp³d², allowing them to have six available binding sites for ligands.
- Ligands can be classified based on the number of binding sites:
- Monodentate Ligands: Bind at one site (e.g., chloride ion, $Cl^{-}$ ).
- Bidentate Ligands: Bind at two sites (example not specified but indicated).
- Multidentate Ligands: More than two binding sites.

Structure of EDTA:
- Stands for ethylenediamine tetraacetic acid, consisting of an ethylene component and multiple acetic acid components.