5. Solutions (15 lessons)

Concepts

  • When substances are mixed, mass is conserved, but volume might not be because particles fill gaps between each other.
  • “Like dissolves like.” Whether a solute can dissolve in a solvent depends on a balance of attractive forces (solute-solvent vs. solvent-solvent and solute-solute). This means that polar substances tend to dissolve in other polar substances, and non-polar substances tend to dissolve in non-polar substances.
  • When molecular (covalent) substances dissolve, their particles remain intact but separate from each other.
  • When ionic solids dissolve, their ionic bonds are actually broken, producing free-floating ions.  This is called dissociation.
  • The concentration of a solution is measured in molarity, meaning mol/L.
  • The greater the concentration of ions dissolved in water, the greater the electrical conductivity of the solution.

Skills

Quiz 5a

  • Based on polarity or ionic charge, predict whether a covalent or ionic species will dissolve in a given solvent.
  • Determine the concentration of a solution.
  • Perform dilution and mixing calculations.

Quiz 5b

  • Describe the effect of a solvent on electrical conductivity.
  • Perform stoichiometric calculations involving solutions.

Homework

Quiz 5a

Quiz 5b

Projects & Labs

Quiz 5a

Quiz 5b

Assessment

  • Quiz 5a: Solubility, concentration, dilutions
  • Quiz 5b: Conductivity, solution stoichiometry
  • Test 5: Solutions