Action of Heat on Substances

The general formula for the combustion of a metal

Metal + Oxygen → Metal Oxide

The general formula for the combustion of a non-metal

Non-Metal + Oxygen → Non-Metal Oxide

The physical changes that take place on Zinc Oxide (ZnO) depending on the temperature

When ZnO is cold it is a white powder

When ZnO is hot it is a yellow powder

Thermally Stable compounds

Compounds that decompose when heated

Thermally Unstable compounds

Compounds that do not decompose when heated

The general formula of the thermal decomposition of metal carbonates, and any exceptions if necessary

Metal Carbonate → Metal Oxide + Carbon Dioxide

Sodium and Potassium carbonates are thermally stable

The carbonates of Aluminium and Iron (3) do not exist

The general formula of the thermal decomposition of metal hydrogen carbonates, and any exceptions if necessary

Metal Hydrogen Carbonate → Metal Carbonate + Carbon Dioxide + Water

Distinguishing between Sodium Carbonate and Sodium Hydrogen Carbonate

Sodium Carbonate is thermally stable whilst Sodium Hydrogen Carbonate isn’t. By heating them you can distinguish between them since Sodium Hydrogen Carbonate (baking powder) decomposes

The general formula of the thermal decomposition of metal nitrates, and any exceptions if necessary

Sodium or Potassium Nitrates → Metal Nitrite + Oxygen

Calcium / Magnesium / Aluminium / Zinc / Iron / Lead / Copper Nitrates → Metal Oxide + Nitrogen Dioxide + Oxygen

2AgNO₃ → 2Ag + 2NO₂ + O₂

The general formula of the thermal decomposition of metal hydroxides, and any exceptions if necessary

Metal Hydroxide → Metal Oxide + Water

Sodium and Potassium Hydroxides are Thermally Stable

The general formula of the thermal decomposition of hydrated compounds, and any exceptions if necessary

Hydrated Compound ⇌ Anhydrous Compound + Water