tests

• describe the test for chlorine

  -Damp litmus paper used

  -Paper will become bleached, turning white in the presence of chlorine
• what colour flame would a potassium ion produce?

  lilac
• what colour flame would a calcium ion produce?

  orange-red
• what colour flame would a copper ion produce?


  Green
• describe the test for hydrogen

  -place burning splint at opening of test tube

  -If hydrogen present will burn rapidly with a squeaky-pop noise
• Describe the test for carbon dioxide

  -calcium hydroxide (limewater) is used for this test

  -When carbon dioxide is shaken with limewater, mixture will turn cloudy
• describe the test for oxygen

  -Place a glowing splint inside a test tube

  -The splint will relight if oxygen is present
• What colour ion would a sodium ion produce?

  yellow
• What colour flame would a lithium ion produce?

  crimson
• describe the flame test to identify metal ions

  1)dip wire loop into sample compound

  2)pass loop over blue bunsen burner

  3)observe colour produced
• describe test for halides

  add couple of drops of dilute nitric solution

  chloride = white

  precipitation of silver chloride

  bromide = cream

  precipitation of silver bromide

  iodide = yellow precipitation of silver iodide
• what is a formulation?

  a mixture that has been designed as a useful product
• what is a pure substance?

  a single element or compound, not mixed with any other substance
• describe the test for carbonate ions

  -Add couple of drops of dilute acid to sample

  -connect test tube to test tube of limewater

  -If present- carbon dioxide produced, solution will turn cloudy
• describe the test for sulphates

  -add a couple drops of dilute HCl

  -followed by barium chloride solution

  -If present- white precipitation of barium sulphate will form
• What solution is added to identify metal ions?

  Sodium hydroxide solution
• which 3 metals form white precipitation

  calcium, magnesium, aluminium
• Name a way you can test for the purity of a substance

  By measuring its melting and boiling point comparing it with a pure substance