Chem Ch12

A solution with components that have observable boundaries, i.e. sand in water.

Soultion that is uniform in appearance, with no observable boundaries, i.e. sweet tea.

How much solute can be dissolved in a given emount of solvent.

Dissolution. Action of components dispersing at a molecular level.

The measure of the dispersal of energy in a system. The more spread out = the higher entrophy.

-ΔH mix >= ΔH solvent + ΔH solute

-Sometimes ΔH mix can be less than ΔH solvent + ΔH solute, but would depend on the intermolecular forces in the solvent & solute.

• ΔH mix > ΔH solvent + ΔH solute then reaction is exothermic
• ΔH mix < ΔH solvent + ΔH solute the reaction is endothermic.

Solution where undissolved solute is in equilibrium with dissolved solute.

A solution that has more solute dissolved than solubility will allow - usually because of increased temperatures.

Reaction where ΔH mix = ΔH solvent + ΔH solute.

Enthalphy and entrophy.

m = mol solute/kg. solvent

χ = mol solute/(mol solute + mol solvent)

mol % = mol solute/(mol solute + mol solvent) * 100

mass solute/mass solution * multiplication factor

• percent by mass (%): 100
• ppm: 10⁶
• ppb: 10⁹

• Vapor pressure lowering
• Freezing point depression
• Boiling point elevation
• Osmotic pressure

A property that depends on the number of particles in a solution, not on the type of particle.

P soln = χ solv ( P⁰ solv)

T_b = imK_b and T_f = imK_f

π = iMRT