Solutions

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Solutions

• IB Chemistry
• Pages 121-122

2

• A solution is a homogeneous mixture of 2 or more
  substances .
• It is made of a solvent and a solute.

3

• SOLUTE the part of a solution that is being
  dissolved (usually the lesser amount)
• SOLVENT the part of a solution that dissolves
  the solute (usually the greater amount)
• Solute Solvent Solution

Solute Solvent Example
solid solid Metal alloys
solid liquid Kool aid
liquid liquid Alcoholic drinks
gas liquid Pepsi
gas gas air
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Concentration of Solute

• The amount of solute in a solution is given by
  its concentration.

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Concentration

• If something is concentrated it has more
  moles/grams of solute per amount of solvent.
• Ex 12 M HCl
• If something is dilute it has less moles/grams of
  solute per amount of solvent
• Ex 0.10 M HCl

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PROBLEM Dissolve 5.00 g of NiCl26 H2O in
enough water to make 250 mL of solution.
Calculate the Molarity.
Step 1 Calculate moles of NiCl26H2O
Step 2 Calculate Molarity
NiCl26 H2O 0.0841 M
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What mass of oxalic acid, H2C2O4, is required to
make 250. mL of a 0.0500 M solution?
moles MV

• Step 1 Change mL to L.
• 250 mL 1L/1000mL 0.250 L
• Step 2 Calculate.
• Moles (0.0500 mol/L) (0.250 L) 0.0125 moles
• Step 3 Convert moles to grams.
• (0.0125 mol)(90.00 g/mol) 1.13 g

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IB Note

• Square brackets 0.60 means
• 0.60 M or
• 0.60 mol/L or
• 0.60 mol dm-3

This is what IB uses!
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Homework

• Page 135 3.92, 3.94 a,b, 3.96, 3.97