Chapter 13 - Properties of Solutions

Homogeneous mixture of solute and solvent.

________________ may be gases, liquids, or solids.

What is doing the dissolving (usually the larger amount).

What is dissolved (typically the smaller amount).

_______________ solutions (aq) contain water as the solvent.

Solutions are formed when one substance _______________.

How many things impact solution formation?

Natural tendency towards ______________ is one thing impacting formation.

______________ forces are one thing impacting formation.

Gases _______________ mix.

Reflects the degree of chaos (thermodynamic quantity that measures the extent of the spreading of the molecules and their associated kinetic energies).

The mixing that occurs as the solution is formed represents a/an ______________ in entropy.

How many kinds of intermolecular attractions are involved in solution formation?

Similar intermolecular forces need ______________ energy to dissolve.

Which states do the intermolecular forces impact?

(Consider the intermolecular attractions between gas molecules)

Interactions between solute particles → BREAK to form solution.

These must be overcome in order for the particles to disperse through the solvent.

Interactions between solvent particles → BREAK to form solution.

These must be overcome to make room for the solute particles in the solvent.

Interactions between solvent and solute particles → FORM solution.

These occur as particles mix.

Nonpolar dissolves in _______________.

Polar dissolves in _____________.

Ionic dissolves in _____________ .

(consider dissociation & intermolecular forces)

Ion dipole forces/interactions between solute and solvent.

Ion dipole forces/interactions between solute and solvent, but with WATER as the solvent.

∆H(solution) = ____________ + ______________

∆H(solution) can be either positive or negative, depending on the __________________________.

Breaking attractive intermolecular forces is always ________________. (solute-solute, solvent-solvent)

∆H(solute) and ∆H(solvent) are both positive.

Forming attractive intermolecular forces is always _________________. (solute-solvent)

∆H(mix) is always negative!

In general, solutions form if the ∆H(solution) is _________________.

If ∆H(solution) is too ________________, a solution will not form.

“Rule of Thumb” for solution formation

Some solutions form by ______________ properties and some by ____________ chemical properties.

Factors affecting _______________:

1. Nature of Solute

2. Nature of Solvent

3. Temperature

4. Pressure

Relationship between Intermolecular Forces and Solubility:

IF+, S+

Favorable ______________ interactions include solute-solute, solvent-solvent, and solute-solvent.

Pairs of liquids that mix in any proportions.

(polar in polar OR nonpolar in nonpolar)

Pairs of liquids that do not mix significantly.

(nonpolar in polar OR polar in nonpolar)

Compounds with possibility of _______________________ usually dissolve better in water.

Substances with _________________ intermolecular forces tend to be soluble in one another.

Which state’s solubility does pressure impact the most?

Relationship between gas pressure and solubility:

P+, S+

(more molecules of the gas get closer to the surface of the solution → higher probability of gas molecule striking surface and entering solution)

Idea that the solubility of a gas in a liquid is directly proportional to the partial pressure of the gas above the solution.

S(g) = kP(g)

[Solubility of gas (mol/L) = constant (mol/L-atm) x partial pressure (atm)

Relationship between temperature and solubility (GAS in a liquid):

T+, S-

(gas particles gain sufficient energy from the heat to escape the solution → thermal pollution!)

Relationship between temperature and solubility (SOLID in a liquid):

T+, S+

(energy given to solid by heat helps break it down to dissolve in the solvent)

Solution that has a relatively small concentration of solute.

Solution that has a relatively high concentration of solute.

One of the easiest ways to express concentration:

(Mass of component in soln / total mass of soln)

x 100%

Concentrations expressed (X) based on the number of moles of one or more components (has NO units):

X = moles of component / total moles of all components

M = moles of solute / liters of solution

(NOTE: M will change with a change in temperature → as the solution volume increases or decreases)

Solid B(ClO)₃ is added to distilled water to produce a solution in which the concentration of chlorate, [ClO₃⁻], is 0.5 M. What is the concentration of the boron ion, [B³⁺], in this solution?

Approximately what mass of NiSO₄ .. 5H₂O (280 g/mol) is required to prepare 300 mL of 0.2 M nickel (II) sulfate solution?

How many moles of K⁺ ions are in 100mL of 0.25 M K₃PO₃ (aq)?