Chemistry Analytic Tests

• Flame test - What colour do lithium ions turn?

  Crimson (red) flame
• Flame test - What colour do sodium ions turn?

  Yellow flame
• Flame test - What colour do potassium ions turn?

  Lilac (purple) flame
• Flame test - What colour do copper(II) ions turn?

  Green flame
• Flame test - What colour do calcium ions turn?

  Orange-red flame
• What forms when sodium hydroxide is added to copper(II) ions?

  Blue precipitate
• What forms when sodium hydroxide is added to calcium ions?

  White precipitate
• What forms when sodium hydroxide is added to magnesium ions?

  White precipitate
• What forms when sodium hydroxide is added to aluminium ions?

  White precipitate (that dissolves when more sodium hydroxide is added)
• What forms when sodium hydroxide is added to iron(II) ions?

  Green precipitate
• What forms when sodium hydroxide is added to iron(III) ions?

  Brown precipitate
• What's a good trick for the sodium hydroxide tests?

  All -ium elements form a white precipitate
• What is the test for chloride, bromide and iodide ions?

  Add nitric acid first, and then add silver nitrate to form the precipitate
• What is the flame test?

  Dip nichrome wire into hydrochloric acid, hold in flame to clean, dip in substance, hold in blue flame and observe colour
• What is the sodium hydroxide test?

  Add sodium hydroxide to a solution containing your sample to form a precipitate
• What forms when testing for chloride ions?

  White precipitate
• What forms when testing for bromide ions?

  Cream precipitate
• What forms when testing for iodide ions?

  Yellow precipitate
• What's a good trick for the nitric acid -> silver nitrate tests?

  The further down group 7, the yellow'er the precipitate
• What is the test for carbonate ions?

  Add dilute acid to the sample and then bubble the produced gas through limewater
• What will happen when testing for carbonate ions?

  The limewater will turn cloudy
• What is the test for sulfate ions?

  Add hydrochloric acid first, and then add barium chloride to form the precipitate
• What forms when testing for sulfate ions?

  White precipitate
• What is the test for oxygen gas and what will the result be?

  Put a glowing splint into the sample of gas, it will re-light if oxygen is present
• What is the test for hydrogen gas and what will the result be?

  Put a lit splint into the sample of gas, it will burn with a squeaky pop if hydrogen is present
• What is the test for chlorine gas and what will the result be?

  Expose damp litmus paper to the sample of gas, it will be bleached if chlorine is present
• What does a Crimson (red) flame mean?

  Lithium ions are present