Solutions

Heterogeneous solutions

Non-uniform combination of substances that are visibly distinct and separate.

Homogeneous

Uniform combination of substances that are evenly distributed throughout.

Solvent

Does the dissolving

Solute

Gets dissolved

Dissolution

The process where a solute dissolves into a solvent to form a solution.

Endothermic solute dissolution

Heat or energy is absorbed from its surroundings to break bonds, causing the temperature to drop.

Exothermic solute dissolution

Heat or energy is released into the surroundings to make bonds, causing the temperature to rise.

Solvent-solvent and solute-solute form what type of thermodynamic data?

Endothermic steps are formed because energy is required to overcome the bonds.

Solvent-solute form what type of thermodynamic data?

Exothermic steps occur because energy is released when new bonds are created.

What is lattice energy?

The amount of energy required to break apart a solid ionic crystal into gaseous ions.

Formula for calculating total energy or enthalpy of a solution (Hess’ Law)

Electrolyte

Forms ions when it dissolves.

Nonelectrolyte

Does not form ions when it dissolves.

Unsaturated solution

Contains less than the maximum amount of solute capable of dissolving.

Saturated solution

Contains the exact maximum amount of solute capable of dissolving at a specific temperature and pressure.

Supersaturated solution

Contains over the maximum amount of solute capable of dissolving than it normally would.

Solubility

The maximum limit of dissolution at a certain temperature and pressure.

Gas solubility v. temperature

They are inversely (increase-decrease) proportional.

Gas solubility v. pressure

They are directly (decrease-decrease) proportional.

Henry’s Law

Immiscible

• The liquids can not mix to form a uniform solution so they separate into distinct layers.

• IMFs are different

Miscible

• The liquids mix into a uniform evenly distributed solution.

• IMF are the same

“Like dissolves like”’

IMFs that are the same will mix into a uniform solution.

Mole fraction calculation steps

1. Find the mass of each component

2. Convert from grams to moles

3. Calculate the total moles

4. Divide the moles of the substances by the total

Molality (m)

Moles of solute / kilograms of solvent

Molarity (M)

Moles of solute / liters of solutions

Molar Mass (MM)

Grams / moles

Solubility units conversion

Use dimensional analysis.

Colligative properties

1. Vapor pressure lowering

2. Boiling point elevation

3. Freezing Point Depression

4. Osmotic Pressure

Formula for vapor pressure lowering

Formula for boiling point elevation

Formula for freezing point depression

Formula for osmotic pressure

Hypotonic solutions

The concentration of dissolved solute is lower outside the cell compared to the inside.

Isotonic Solutions

The concentration of dissolved solute is exactly equal inside the cell compared to the surroundings.

Hypertonic Solutions

The concentration of dissolved solute is higher outside the cell compared to the inside.

Solvent in osmosis

Moves through a semipermeable membrane to dilute a higher concentration of solute.

Solvent in reverse osmosis

An external pressure forces the solvent to move backward through the semipermeable membrane away from the high-solute to create a pure solvent.

Electrolytes v. colligative properties

Increase the magnitude of colligative properties because they increase the concentration by breaking apart into ions.

Ideal Van’t Hoff factor calculation steps:

1. Identify and separate the ions

2. Write a balanced equation

3. Count the coefficients