• Thermal decomposition?is the term used to describe reactions where a substance breaks down due to the action of heat
• One such reaction is the thermal decomposition of?metal carbonates
• Carbonates of metals from the lower half of the reactivity series tend to decompose on heating to produce the?metal oxide?and?carbon dioxide?gas:

metal carbonate →?metal oxide + carbon dioxide

The thermal decomposition of copper(II)carbonate

• The thermal decomposition of copper(II)carbonate occurs readily on heating
• Copper(II) carbonate?is a green powder and slowly darkens as black?copper(II) oxide?is produced
• The carbon dioxide given off can be tested by passing the gas through?limewater?and looking for it to turn milky
• The equation for the reaction is

CuCO₃?(s)?→??CuO (s)+ CO₂??(g)?

copper(II) carbonate → copper(II) oxide + carbon dioxide