Chemistry Chapter 16.2

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Chemistry Chapter 16.2
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• Molarity
• The concentration of a solution is a measure of
  the amount of solute that is dissolved in a given
  quantity of solvent. A dilute solution is one
  that contains a small amount of solute. By
  contrast, a concentrated solution contains a
  large amount of solute.

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• The terms concentrated and dilute are only
  qualitative descriptions of the amount of a
  solute in solution

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• Molarity (M) is the number of moles of solute
  dissolved in one liter of solution. To calculate
  the molarity of a solution, divide the moles of
  solute by the volume of the solution.

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• Molarity is also known as molar concentration.
  When the symbol M is accompanied by a numerical
  value, it is read as molar. For example, a
  solution labeled 3M NaCl is read as three molar
  sodium chloride solution.

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• Diluting a solution reduces the number of moles
  of solute per unit volume, but the total number
  of moles of solute in solution does not change.

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• Moles of solute before dilution moles of solute
  after dilution

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• Moles of solute M1 V1 M2 V2

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• M1 and V1 are the molarity and volume of the
  initial solution, and M2 and V2 are the molarity
  and volume of the diluted solution. Volumes can
  be in liters or milliliters, as long as the same
  units are used for both V1 and V2.

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• Percent Solutions
• Another way to describe the concentration of a
  solution is by the percent of a solute in the
  solvent. The concentration of a solution in
  percent can be expressed in two ways as the
  ratio of the volume of the solute to the volume
  of the solution or as the ratio of the mass of
  the solute to the mass of the solution.

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• Concentration in Percent (Volume/Volume)
• If both the solute and the solvent are liquids, a
  convenient way to make a solution is to measure
  the volumes of the solute and the solution. The
  concentration of the solute is then expressed as
  a percent of the solution by volume

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• 16) Key Concept How do you calculate the molarity
  of a solution? Hint
• (17) Key Concept Compare the number of moles of
  solute before dilution with the number of moles
  of solute after dilution. Hint
• (18) Key Concept What are two ways of expressing
  the concentration of a solution as a percent? Hint

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• 19)Calculate the molarity of a solution
  containing 400 g CuSO4 in 4.00 L of solution.

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• (20)How many moles of solute are present in 50.0
  mL of 0.20M KNO3?
• (21)How many milliliters of a stock solution of
  2.00M KNO3 would you need to prepare 100.0 mL of
  0.150M KNO3?

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• (22)What is the concentration, in percent (v/v),
  of a solution containing 50 mL of diethyl ether
  (C4H10O) in 2.5 L of solution?
• (23)How many grams of K2SO4 would you need to
  prepare 1500 g of 5.0 K2SO4 (m/m) solution?