Solutions

Water

• Water is a triatomic molecule, which means it is composed of three atoms.
• The O-H bonds in water are highly polar.
• The bond angle of water is 105 degrees.
• Water, as a whole is polar because of the bent shape.
• Hydrogen bonding gives water low vapor pressure and high surface tension.

Solvents and solutes

• Solution - A homogeneous mixture that is mixed molecule by molecule. 
• Solvent - A substance that is able to dissolve other substances. 

Electrolytes

• Electrolytes - A substance that can form ions in an aqueous solution.
• Ionic compounds are electrolytes, or "salts".
• Most electrolytes are materials because they lack ions.
• Some electrolytes are weak, and some are strong. 
• Strength of electrolytes is based on degree of ionization.

Aqueous Solutions

• Aqueous Solution - A solution in which the solvent is water. 
• Water dissolves ionic compounds and covalent molecules best.
• Rule: A dissolves A
• Polar dissolves polar
• Nonpolar dissolves nonpolar

The Solution Process

• The solution process is called "solvation".
• When a solution is formed, solvents pull solutes apart.
• The solvent will surround, or solvate, the solute particles.

Solutions

• To dissolve, solvent molecules need to contact solute molecules.
• Stirring and grinding can increase contact.
• There are saturated, supersaturated, and unsaturated solutions. 

Supersaturated solutions

• Created by heating a solution and dissolving solute and slowly cooling.
• Unstable solutions have the ability to be recrystallized.
• Techniques to recrystallize include shaking or using a seed crystal.

Solubility

• If water force is stronger than crystal force, solids dissolve.
• If liquids dissolve in each other, they are miscible.
• Water doesn't dissolve nonpolar molecules.
• Two liquids that don't mix due to polarities are immiscible.
• Affected by pressure and temperature.

Concentration of Solutions

• The amount of substance per space, typically in mass per volume units.
• Dilute solutions have low concentration of solute.
• Concentrated solutions have high concentration of solute.
• We use molarity and percent solutions to compare and express solutions.

Molarity of Solutions

• Molarity (M) = number of moles of solute per liter of solution
• Molarity (M) = mol/L
• Example: 4 mol glucose dissolved in 8 L? 4 mol/8 L = 1.5 M

All information in this slideshow was obtained through Ms. Cool's Unit 10 packet.