Solutions

Solution definitionsCalculating Molarity

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Formation of solutions• Solution: – Homogeneous mixture… the best mixed mixture.

Solutions contain 2 parts:– Solute: the stuff dissolving– Solvent: the stuff its dissolved into

Salt water,Salt =?Water=?

Solute

Solvent

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Saturated and unsaturated solutions.

• Saturated:– Contains the maximum

amount of solute for a given amount of solvent

(@ constant T)

• Unsaturated:– Contains less than

the maximum solute for a given solvent.

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Factors affecting solubility

1. Temperature 1. Higher temp usually = higher solubility

2. Gas pressure above the liquidHenry’s Law Higher pressure = more gas

dissoved.

3. Solute solvent relationshipPolar or non-polar

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Principles of SolubilityNature of the solute and solvent

• Like likes like.

Electrolytes will dissolve in a polar solvent (like water)

Non-electrolytes will dissolve more easily in non polar or slightly polar solvents (like benzene, or toluene)

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Concentration UnitsMolarity (M)

Molarity = moles of solute/liters of solution

Units:mol/L

Tricks:1. change mass to moles2. change mL to Liters

• There are 6.0 moles of NaCl in a 500 mL of water, what is the molarity?

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Molarity calculations

• 500.0mL of potassium chloride solution is made by putting 85.0g into water.

• What is the molarity of a solution made by dissolving 16.9 g of NaOH in enough water to make 250.0 mL of solution.