III. Molarity

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III. Molarity

• Topic 9 The Mole

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A. Molarity

• Concentration of a solution.

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A. Molarity
What does this mean? You would read this
as Hydrochloric acid with a Molarity of 2.
2M HCl
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Conversion FactorsWe are really just adding one
more of them.
6.02 ? 1023 (particles/mol)
6.02 ? 1023 (particles/mol)
molar mass (g/mol)
molar mass (g/mol)
molar mass (g/mol)
MASS IN GRAMS
MOLES
NUMBER OF PARTICLES
MOLES
NUMBER OF PARTICLES
MASS IN GRAMS
Molarity (mol/L) Aqueous solution
LITERS OF SOLUTION
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• Ex 1). What is the molarity of a solution
  containing 0.32 moles of NaCl in 3.4 liters?
• molarity 0.32 moles NaCl 3.4 L
• 0.094 M NaCl

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• Ex 2). Find the molarity of a 250 mL solution
  containing 10.0 g of NaF.

10.0 g
1 mol 41.99 g
0.238 mol NaF
0.238 mol 0.25 L
0.95M NaF
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• Ex 3). How many grams of NaCl are required to
  make 0.500L of 0.25M NaCl?

0.500 L
0.25 mol 1 L
58.44 g 1 mol
7.3 g NaCl
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• How would you prepare 400. ml of 1.20 M solution
  of sodium chloride?
• Remember1.20 M NaCl 1.20 moles NaCl1.00 L
  solution0.400 L solution x1.20 moles NaCl1.00 L
  solution0.480 moles NaCl0.480 moles NaCl x58.5 g
  NaCl1 mole NaCl28.1 g NaCl
• Dissolve 28.1 g NaCl in enough water to make 400
  mL of solution.