Mixtures with a solute and a solvent.

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Solutions

• Mixtures with a solute and a solvent.
• Solute the solute is what is being dissolved.
• Solvent the solvent is what is doing the
  dissolving.
• How things dissolve
• Polar Molecules are like magnets, one end is
  positive the other is negative.
• Polar molecules can only dissolve other polar
  molecules.
• Non-polar molecules must be dissolved by other
  non-polar molecules.

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Polarity
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Types of Solutions

• Solutions may exist as a gas, liquid, or solid
  depending on the state of matter of the solvent.
• Gas solutions
• Example Air Solvent Nitrogen Solute
  Oxygen
• Liquid Solutions
• Gas in Liquid
• Carbonated Water Solvent Water Solute Carbon
  dioxide
• Liquid in Liquid
• Vinegar Solvent Water Solute Acetic Acid
• Solid in Liquid
• Ocean Water Solvent Water Solute NaCl
• Solid Solutions
• Example Steel Solvent Iron Solute Carbon

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Solutions as Electrolytes

• Solutions of salts, for example NaCl, are good
  conductors of electricity. Why?
• Solutions of acids are also good conductors of
  electricity. Why?
• Solutions of covalent compounds such as sugar are
  not good conductors of electricity. Why?

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Solubility

• Refers to the maximum amount of solute that will
  dissolve in a given amount of solvent at a
  specified temperature and pressure.
• Solubility can usually be expressed in grams of
  solute per 100 grams of solvent.
• NaCl (at 0 degrees Celsius) 35.7g/100 g H2O
• (at 20 degrees Celsius) 35.9 g/100 g H2O
• (at 40 degrees Celsius ) 36.4 g/100 g H2O

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Factors that Effect Solubility

• Temperature many substances are more soluble at
  higher temperatures.
• Pressure solubility increases as a substances
  external pressure increases.
• Surface Area increasing surface area increases
  solubility.
• Henrys Law (for gases only) States that at a
  given temperature, the solubility (S) of a gas in
  a liquid is directly proportional to the pressure
  (P) of the gas.

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Solubility Curve
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Solubility Cont.

• Saturated Solution a solution that contains the
  maximum amount of dissolved solute for a given
  amount of solvent.
• Unsaturated Solution contains a less dissolved
  solute for a given temperature and pressure than
  a saturated solution.
• Supersaturated Solution a solution that has
  more solute dissolved than it can hold.

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Solution Concentration

• Concentration is a measure of how much solute is
  dissolved in a specific amount of solvent of
  solution.
• Percent Concentration ()
• Molarity (M) moles/L
• Molality (m) moles/kg

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Percent Concentration

• Percent by mass formula
• mass (g) of solute
• --------------------------- x 100
• mass (g) of solutions
• percent by volume replace with volume (L)
  instead of mass
• Example In order to maintain a sodium chloride
  concentration similair to ocean water, an
  aquarium must contain 3.6 g of NaCl per 100 g of
  water. What is the by mass of NaCl in the
  solution?

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Molarity

• The number of moles of solute per liter (L) of
  solution.
• Molarity (M) Formula
• moles of solute
• --------------------------
• liters of solution
• Example What is the molarity of a solution
  produced when 4 moles of NaCl is dissolved by
  1000mL of water?

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Molality

• Sometimes we need to use mass because it does not
  change with temperature.
• Molality formula (m)
• moles of solute
• -------------------------
• kilograms of solvent

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Diluting Solutions

• We use this formula in chemistry when we dilute
  solutions.
• Dilution Formula
• M1V1 M2V2
• M Molarity (M)
• V Volume (L)