Types of Mixtures

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Types of Mixtures

• Learning Target
• Compare properties of different mixtures
• Properties of solutions

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Main Idea Mixtures can either be heterogeneous
or homogeneous

• Heterogeneous mixtures visible different parts
• Suspensions mixtures containing particles that
  settle down when left undisturbed. Ex muddy
  water
• Thixotropic mixtures solid like mixtures that
  flow like liquids when stirred or agitated. Ex
  toothpaste, some paints
• Colloids A heterogeneous mixture of intermediate
  particles, and can settle out of solution. Ex
  milk, whipped cream

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• Homogeneous mixtures uniform throughout
• solutions
• Parts of a solution
• Solute substance that gets dissolved in another
  substance
• Solvent substance that does the dissolving

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Types of Solutions

• Gas Solutions
• solute gas, solvent gas
• Ex air
• Liquid Solutions
• Solvent liquid, solute solid, liquid, or gas
• Ex soda, sea water, antifreeze (ethylene glycol
  in water)
• Solid solutions
• Solvent solid, solute solid, liquid, gas
• Ex alloys, dental filling (mercury in Silver),
  charcoal filter (toxic gases in carbon)
• Aqueous solutions
• Solvent water

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Forming solutions

• A substance that dissolves in a solvent is said
  to soluble.
• Two liquids that are soluble in each other in any
  proportion are said to be miscible.
• A substance that does not dissolve in a solvent
  is said to be insoluble.
• Two liquids that are mixed together, but
  eventually separate are immiscible.

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Solution Concentration

• Measure of how much solute is dissolved in
  specific amount of solvent.
• Described qualitatively as concentrated
  (containing large amount of solute) or dilute
  (containing small amount of solute).
• Expressed quantitatively in terms of percent
  (percent by mass, percent by volume) or moles
  (molarity, molality).

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Concentration Ratios (by percent)

• Percent by mass mass of solute x 100 mass
  of solution
• Percent by volume volume of solute x
  100 volume of solution

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Example

• What is percent by mass of NaCl if 3.6 g of salt
  is dissolved in 100.0 g of water?
• Answer
• mass mass of solute x 100 mass of
  solution mass of solution mass of solute
  mass of solvent
• mass 3.6 g x 100 3.5 100.3 g

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Example

• 2. If 18 mL of methanol is used to make an
  aqueous solution that is 15 methanol by volume,
  how many milliliters of solution is produced?

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Molarity (M)

• Number of moles of solute dissolved per liter of
  solution.
• M moles of solutes/ liters of solution
• Molality (m) ratio of number of moles of solute
  dissolved in Kg solvent.
• m moles of solute / kg of solvent