flame tests

• pure substances are made of a single element or single compound
• pure substances have a fixed melting and boiling point
• impure substances have a range of melting and boiling points
• formulations are a mixture of substances with specific quantaties of each components
• how to carry out a flame test

  1. add unknown chemical on wire
  2. place it on a blue flame bunsen burner
  3. ! its hard to do with a low concentration
  4. ! the unkown chemical may be a mixture so the stronger flame may mask the other flames
• flame test

  1. lithium → crimson
  2. sodium → yellow
  3. pottasium → lilac
  4. calcium → red / orange
  5. copper → green
• flame emission spectroscopy is an instrumental method
• flame emission spectroscopy

  1. place small amounts of chemical and burn it
  2. pass the light through the spectroscope
  3. the spectroscope converts light into a line spectrum
  4. ( each metal ion has a specific line spectrum )
• line spectrums can even tell concentrations , the higher the concentrations the more intense the line is
• advantages of a flame emission spectroscopy

  • + its a rapid test
  • + its accurate
  • + its sensetive which allows you to use small samples