Physical Properties of Solutions

• Solution


  Homogeneous mixture (uniform properties throughout) of two or more substances with each substance retaining its own chemical identity
• Solvent


  Component present in the greatest amount, the medium in which the other substances present are dissolved
• Solute


  Component present in a lesser amount relative to that of the solvent, the active ingredients in the solution that will undergo reaction when solutions are mixed
• Saturated solution


  • Contains the maximum amount of solute that can be dissolved under the conditions at which the solution exists, additional solute will not dissolve if added
• Unsaturated solution


  • Contains less than the maximum amount of solute that can be dissolved under the conditions at which the solution exists
• Supersaturated solution


  • Contains more solute than is present in a saturated solution, not very stable and some solute will come out as crystals
• Concentrated solution


  Contains a large amount of solute relative to the amount that could dissolve, does not have to be a saturated solution
• Dilute solution


  Contains a small amount of solute relative to the amount that could dissolve
• Aqueous solution


  Solution in which water is the solvent
• Nonaqueous solution


  Solution in which a substance other than water is the solvent
• How solutions are formed

  Solute-solvent attractions overcome solute-solute and solvent-solvent attractions, allowing particles to intermingle and form a new solution
• Factors affecting rate of solution formation


  • State of subdivision of solute
  • Degree of agitation
  • Temperature
• Solubility


  Maximum amount of solute that will dissolve in a given amount of solvent under a given set of conditions, commonly expressed as grams of solute per 100 grams of solvent
• Factors affecting solubility

  • Solute-solvent interactions
  • Temperature
  • Pressure
• Solute-solvent interactions


  Nonpolar substances are more likely to be soluble in nonpolar solvents, ionic and polar solutes are more likely to be soluble in polar solvents
• Temperature effect on solubility

  Solubility of most solid solutes increases as temperature increases, solubility of gases decreases as temperature increases
• Pressure effect on solubility


  Solubility of gases increases as pressure increases, solubility of solids and liquids not appreciably affected by pressure
• Percent by mass (mass-mass percent)

  Mass of solute divided by total mass of solution, multiplied by 100
• Percent by volume (volume-volume percent)


  Volume of solute divided by total volume of solution, multiplied by 100
• Mass-volume percent


  Mass of solute divided by total volume of solution, multiplied by 100
• Parts per million (ppm)


  Ratio of mass of solute to mass of solution, multiplied by 1,000,000
• Parts per billion (ppb)


  Ratio of mass of solute to mass of solution, multiplied by 1,000,000,000
• Molarity (M)


  Number of moles of solute in 1 L of solution
• Molality (m)


  Number of moles of solute dissolved in 1 kg (1000 g) of solvent