Chemistry and Our Universe: How It All Works Season 1 Episode 29 Colligative Properties of Solutions
- TV-PG
- September 23, 2016
- 32 min
In season 1 episode 29 of Chemistry and Our Universe: How It All Works, titled "Colligative Properties of Solutions," host Dr. Michelle Francl explores how the properties of a solution change when solutes are added. She explains that certain properties, such as boiling point and freezing point, depend not only on the identity and amount of the solvent, but also on the amount and type of solute present.
Dr. Francl begins by discussing Raoult's law, which states that the vapor pressure of a solvent above a solution is directly proportional to the mole fraction of the solvent. This law explains why adding a nonvolatile solute to a solvent causes the boiling point of the solution to increase and the freezing point to decrease; because the solute molecules lower the vapor pressure of the solvent, they must be heated to a higher temperature or cooled more to reach their boiling or freezing point.
Dr. Francl then demonstrates an experiment to measure the boiling point elevation and freezing point depression of solutions. By adding different amounts of salt to water and measuring the resulting changes in boiling and freezing points, she shows how colligative properties can be used to determine the molar mass of an unknown solute.
Finally, Dr. Francl discusses the importance of colligative properties in everyday life. For example, road salt is used to lower the freezing point of ice and prevent accidents on winter roads, while antifreeze is used to prevent the engine coolant in vehicles from freezing in cold temperatures. Understanding the science behind colligative properties is essential for designing effective and safe solutions for these practical problems.
Overall, "Colligative Properties of Solutions" provides a clear and engaging explanation of an important concept in chemistry. Dr. Francl's enthusiasm and expertise make the episode a must-watch for anyone interested in chemistry or the science behind everyday materials.
