molarity

• Dilute solution


  Contains a small amount of solute
• Concentrated solution


  Contains a large amount of solute
• Molarity (M)


  Number of moles of solute dissolved in one liter of solution
• Making a 0.5M solution

  1. Add 0.5 mol of solute to 1-L volumetric flask half filled with distilled water

  2. Swirl flask to dissolve solute

  3. Fill flask with water to 1-L mark
• 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
• Making a 0.40M MgSO4 solution from 2.0M MgSO4 stock

  1. Measure 20 mL of stock solution

  2. Transfer 20 mL to 100-mL volumetric flask

  3. Add water to 100-mL mark
• Volume-measuring devices include pipets and volumetric flasks
• The concentration of a solution in percent can be expressed as the ratio of the volume of the solute to the volume of the solution or the ratio of the mass of the solute to the mass of the solution
• Percent (Volume/Volume)


  • 91% isopropyl alcohol solution consists of 91 mL isopropyl alcohol and enough water to make 100 mL solution
• To make a 1.00M aqueous solution of NaCl, 58.4 g of NaCl are dissolved in enough water to make 1.00 liter of solution
• The mass of sodium iodide (NaI) in 250 mL of a 0.500M solution is 18.7 g
• Diluting a solution does not change the moles of solute
• In a 2000 g solution of glucose that is labeled 5.0% (m/m), the mass of water is 1995 g