27 Colligative Properties

27 Colligative Properties - Enthalpy of Solution The...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon
1 1 Enthalpy of Solution Note: It always costs you the lattice energy and you get back the hydration energy, so figure out the +/- signs from that. The enthalpy of solution , H solution , is the energy that is transferred from the reacting system to the surroundings when a solution is formed at constant temperature and pressure. The enthalpy of solution is the sum of the lattice energy and the hydration energy with the appropriate signs. Consider NaCl(s) Na +( aq) + Cl - (aq) Energy is needed to separate the ions. This energy is called the lattice energy . Then energy is released when the ions are solvated (i.e. interact with water molecules) to form the solution. This energy is called the solvation energy or hydration energy . For NaCl, the lattice energy is 790 kJ/mol and the hydration energy is 780 kJ/mol. What is the enthalpy of solution for sodium chloride? Respond in kJ/mol. 2 What do you think? The vapor pressure of sea water is _____________ the vapor pressure of pure water? A) higher than B) the same as C) lower than
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
2 3 Fig. 15-14, p. 745 A really neat measurement of the difference! 4 Measurement shows that the vapor pressure of salty water is linearly proportional to the mole fraction of the water (solvent) in the solution. The vapor pressure of the solvent is lowered by the presence of non-volatile solute particles. A colligative property!
Background image of page 2
3 5 Colligative Properties Colligative properties are properties of solutions that depend on the concentration of particles (number of molecules or number of ions if
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 4
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 02/13/2011 for the course CHE 132 taught by Professor Hanson during the Spring '08 term at SUNY Stony Brook.

Page1 / 11

27 Colligative Properties - Enthalpy of Solution The...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online