Aqueous Solutions Solution - a homogenous mixture mixed molecule by molecule. Solution - a homogenous mixture mixed molecule by molecule. Solvent - the stuff that does the dissolving. Solvent - the stuff that does the dissolving. Solute -the stuff that is dissolved. Solute -the stuff that is dissolved. Aqueous solution- a solution with water as the solvent. Aqueous solution- a solution with water as the solvent.

Aqueous Solutions Water dissolves ionic solids and polar covalent solids best. Water dissolves ionic solids and polar covalent solids best. The rule is “like dissolves like” The rule is “like dissolves like” Polar dissolves polar. Polar dissolves polar. Nonpolar dissolves nonpolar. Nonpolar dissolves nonpolar. Oil is non polar. Oil is non polar. Oil and water don’t mix. Oil and water don’t mix. Salt is ionic- salt water. Salt is ionic- salt water.

How Ionic solids dissolve Called solvation. Called solvation. Water breaks the + and - charged pieces apart and surround them. Water breaks the + and - charged pieces apart and surround them.

How Ionic solids dissolve H H O H H O H H O H H O H H O H H O H H O H H O H H O

Solids will dissolve if the attractive force of the water molecules is stronger than the attractive force of the crystal. Solids will dissolve if the attractive force of the water molecules is stronger than the attractive force of the crystal. If not the solids are insoluble. If not the solids are insoluble. Water doesn’t dissolve nonpolar molecules because the water molecules can’t hold onto them. Water doesn’t dissolve nonpolar molecules because the water molecules can’t hold onto them. The water molecule hold onto each other and separate from the polar molecules. The water molecule hold onto each other and separate from the polar molecules.

Hydration Water molecules chemically bonded to solid salt molecules. Water molecules chemically bonded to solid salt molecules. These compounds have fixed amounts of water. These compounds have fixed amounts of water. The water can be driven off by heating. The water can be driven off by heating. CuSO 4. 5H 2 O CuSO 4 + 5H 2 O CuSO 4. 5H 2 O CuSO 4 + 5H 2 O Called copper(II)sulfate pentahydrate. Called copper(II)sulfate pentahydrate. - heat + heat

Electrolytes Substances that conduct electricity when dissolved in water. Substances that conduct electricity when dissolved in water. Must have charged particles that can move. Must have charged particles that can move. Ionic compounds break into charged ions. Ionic compounds break into charged ions. NaCl  Na + + Cl - NaCl  Na + + Cl - These ions can conduct electricity. These ions can conduct electricity.

Non electrolytes Non electrolytes do not conduct electricity when dissolved in water. Non electrolytes do not conduct electricity when dissolved in water. Polar covalent molecules such as methanol CH3OH don’t fall apart into ions when they dissolve. Polar covalent molecules such as methanol CH3OH don’t fall apart into ions when they dissolve. Weak electrolytes don’t fall completely apart into ions. Weak electrolytes don’t fall completely apart into ions. Strong electrolytes do ionizes completely. Strong electrolytes do ionizes completely.

Mixtures that are NOT Solutions Suspensions are mixtures that slowly settle upon standing. Suspensions are mixtures that slowly settle upon standing. Particles of a suspension are more than 100 times bigger. Particles of a suspension are more than 100 times bigger. Can be separated by filtering. Can be separated by filtering. Colloids particles are between the size of a solid and that of a liquid. Colloids particles are between the size of a solid and that of a liquid.