* Vapor pressure is the pressure exerted by the vapor of a liquid in equilibrium with its liquid phase.
* Colligative properties are properties of solutions that depend on the concentration of solute particles, not their identity. Lowering vapor pressure is one of these colligative properties.
* Sodium chloride (NaCl) is an ionic compound that dissociates into two ions (Na+ and Cl-) when dissolved in water. This means that a 1 M solution of NaCl will have a higher concentration of dissolved particles than a 1 M solution of a non-ionic compound like sugar.
How it works:
* Pure water: Water molecules have a relatively high tendency to escape into the vapor phase, leading to a higher vapor pressure.
* Aqueous NaCl solution: The dissolved ions (Na+ and Cl-) interact with the water molecules, making it harder for water molecules to escape into the vapor phase. This reduces the vapor pressure.
In summary: The presence of dissolved sodium chloride ions in the solution lowers the vapor pressure compared to pure water. This is a direct result of the colligative property known as vapor pressure lowering.
