Flame Test

Flame Test Metal Barium chloride Calcium chloride Copper (II) sulfate Potassium chloride Sodium chloride 2. Test for Cu+2, Fe+³, Pb+2, Zn +2 Solution Cu2 in Copper (II) sulfate Fe3 in Iron (III) chloride Zn2 in Zinc sulfate Fe2 in Iron (II) sulfate Pb+2 in Lead nitrate Reaction with Sodium Hydroxide Color Flame Reaction with Ammonia

The Correct Answer and Explanation is :

The flame test and reactions with sodium hydroxide (NaOH) and ammonia (NH₃) are fundamental methods for identifying metal ions in solution.Below is a detailed explanation of these tests for the specified metal salts and ions:

1. Flame Test:

hen metal salts are introduced into a flame, the heat excites electrons in the metal ions, causing them to emit light at characteristic wavelengths.

• Barium chloride (BaCl₂): roduces a light apple green flame.citeturn0search20
• Calcium chloride (CaCl₂): ields a brick-red flame.citeturn0search20
• Copper(II) sulfate (CuSO₄): ives a blue-green flame.citeturn0search20
• Potassium chloride (KCl): enerates a lilac (light purple) flame.citeturn0search20
• Sodium chloride (NaCl): roduces a bright yellow flame.citeturn0search20
  2. Reactions with Sodium Hydroxide and Ammonia:

dding NaOH or NH₃ to solutions containing metal ions can lead to the formation of precipitates or complex ions, aiding in their identification.

• Cu²⁺ (from Copper(II) sulfate): – With NaOH: orms a light blue precipitate of copper(II) hydroxide (Cu(OH)₂). – With NH₃: nitially forms a light blue precipitate of Cu(OH)₂, which dissolves in excess NH₃ to form a deep blue solution of the tetraamminecopper(II) complex, [Cu(NH₃)₄]²⁺.citeturn0search3
• Fe³⁺ (from Iron(III) chloride): – With NaOH: roduces a reddish-brown precipitate of iron(III) hydroxide (Fe(OH)₃). – With NH₃: orms a similar reddish-brown precipitate of Fe(OH)₃.citeturn0search5
• Zn²⁺ (from Zinc sulfate): – With NaOH: orms a white precipitate of zinc hydroxide (Zn(OH)₂), which dissolves in excess NaOH to form a colorless solution of the zincate ion, [Zn(OH)₄]²⁻. – With NH₃: orms a white precipitate of Zn(OH)₂, which dissolves in excess NH₃ to form a colorless solution of the tetraamminezinc(II) complex, [Zn(NH₃)₄]²⁺.citeturn0search26
• Fe²⁺ (from Iron(II) sulfate): – With NaOH: orms a dirty green precipitate of iron(II) hydroxide (Fe(OH)₂), which may oxidize to Fe(OH)₃ upon standing. – With NH₃: orms a similar dirty green precipitate of Fe(OH)₂.citeturn0search7
• Pb²⁺ (from Lead nitrate): – With NaOH: orms a white precipitate of lead(II) hydroxide (Pb(OH)₂), which dissolves in excess NaOH to form a colorless solution of the plumbate ion, [Pb(OH)₄]²⁻. – With NH₃: orms a white precipitate of Pb(OH)₂, which dissolves in excess NH₃ to form a colorless solution of the tetraamminelead(II) complex, [Pb(NH₃)₄]²⁺.citeturn0search5
  hese reactions are essential for qualitative inorganic analysis, allowing chemists to identify metal ions based on their characteristic flame colors and precipitation behaviors with hydroxide ions.