1. Do Now:
Define the term concentration as it relates to a solute in a solution.
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2. A. Concentration The amount of solute in a solution.
Describing Concentration
% by mass - medicated creams
% by volume - rubbing alcohol
ppm, ppb - water contaminants
molarity - used by chemists
molality - used by chemists
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3. B. Molality
mass of solvent only
1 kg water = 1 L water
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4. B. Molality
Find the molality of a solution containing 75 g of MgCl2 in 250 mL of water.
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5. B. Molality
You try one:
What is the molality of a solution containing 3500 mL of water and g of SrCl2?
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6. C. Dilution
Preparation of a desired solution by adding water to a concentrate.
Moles of solute remain the same.
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7. C. Dilution
What volume of 15.8M HNO3 is required to make 250 mL of a 6.0M solution?
GIVEN:
M1 = 15.8M
V1 = ?
M2 = 6.0M
V2 = 250 mL
WORK:
M1 V1 = M2 V2
(15.8M) V1 = (6.0M)(250mL)
V1 = 95 mL of 15.8M HNO3
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8. C. Dilution
You try one! What molarity of HCl acid is the result of the volume of a 75mL, 12.0 molar HCl acid solution being increased to mL?
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9. D. Recalling Molarity Molarity (M) = mol solute Let’s try one:
L of soln.
Let’s try one:
mass 45.0 g of NaCl
total volume of solution is 500 mL
500 mL
mark
volumetric
flask
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10. D. Recalling Molarity You try one…
A 250 ml solution is made with 0.50 moles of NaCl.  What is the Molarity of the solution?
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