This document discusses transition elements and their compounds. It describes how transition element compounds are often colored, making them useful as pigments and dyes. It also discusses the thermal decomposition of transition metal carbonates into metal oxides and carbon dioxide. Finally, it explains how transition metal ions can be identified through precipitation reactions with sodium hydroxide solution, noting the color of precipitates formed for copper, iron(II), and iron(III) ions.

1. Transition elements

2. Need to know:
• Appearance and uses of transition elements
• Thermal decomposition of transition metal
carbonates - equations
• Identification of TM ions using precipitation

3. Compounds of transition elements
Copper sulphate Iron II sulphate Iron III oxide
Compounds of transition elements are often ________
This makes them good for . . . .

4. Compounds of transition elements
Copper sulphate Iron II sulphate Iron III oxide
Compounds of transition elements are often coloured
This makes them good for pigments and dyes

6. Transition elements and their
compounds can also be used as a
e.g.
Iron in the Haber process
Nickel in the manufacture of margarine

7. Thermal decomposition of carbonates
of transition elements
Note:
Colour change
Copper carbonate → ______ _____+ _____ _______

8. Thermal decomposition of carbonates
of transition elements
Note:
Colour change
Copper carbonate → copper oxide + carbon dioxide

9. video

11. Try these equations for
thermal decomposition. . .
• Iron carbonate →
• Copper carbonate →
• Manganese carbonate →
• Zinc carbonate →

12. Try these equations for
thermal decomposition. . .
• Iron carbonate → iron oxide + carbon dioxide
• Copper carbonate → copper oxide + carbon dioxide
• Manganese carbonate → manganese oxide + carbon dioxide
• Zinc carbonate → zinc oxide + carbon dioxide

13. Try these equations for
thermal decomposition. . .
• Iron carbonate → iron oxide + carbon dioxide
FeCO3 → FeO + CO2
• Copper carbonate → copper oxide + carbon dioxide
CuCO3 → CuO + CO2
• Manganese carbonate → manganese oxide + carbon dioxide
MnCO3 → MnO + CO2
• Zinc carbonate → zinc oxide + carbon dioxide
ZnCO3 → ZnO + CO2

14. How can you identify
transition metal ions?
Precipitation reactions

15. video
Colour of
precipitates
formed
Precipitate formed
Transition metal ions when mixed with Colour of the
in solution sodium hydroxide precipitate
solution
Cu2+ Copper hydroxide Blue
Fe2+ Iron(II)hydroxide Grey/green
Fe3+ Iron(III)hydroxide Orange/red

16. Extension : write balanced ionic equations
for the precipitation reactions
Cu2+ + OH- →
Fe2+ + OH- →
Fe3+ + OH- →

17. Extension : write balanced ionic equations
for the precipitation reactions
Cu2+ + 2OH- → Cu(OH)2
Fe2+ + 2OH- → Fe(OH)2
Fe3+ + 3OH- → Fe(OH)3

18. Need to know:
• Appearance and uses of transition elements
• Thermal decomposition of transition metal
carbonates - equations
• Identification of TM ions using precipitation