Heating effect on carbonate salts

Heating Effect on Carbonate Salts

All carbonates salts except potassium carbonate and sodium carbonate can be decomposed by heat to produce carbon dioxide gas.

Aluminum carbonate

Al2(CO3)3 → Al2O3 + 3CO2

Copper carbonate

CuCO3 → CuO + CO2Mercury(II) carbonate

Silver carbonate

Aurum(II) carbonate Silver carbonate

2Ag2CO3 → 2Ag + 2CO2 + O2Ammonium carbonate(NH4)2CO3 → 2NH3 + 2CO2 + H2O

Heating Effect on Nitrate Salts

All nitrates salts decompose when heated.

Table below shows the products formed when different nitrate salts are heated.

Nitrate Salt Equation of The Reaction

Ammonium nitrate Ammonium nitrate decompose to nitrogen monoxide and water vapour when heated.

NH4NO3 → N2O + 2H2OPotassium nitrate

Sodium nitratePotassium nitrate

2KNO3 → 2KNO2 + O2

Sodium nitrate

2NaNO3 → 2NaNO2 + O2Calcium nitrate

Magnesium nitrate

Aluminium nitrate

Zink nitrate

Iron (III) nitrate

Lead(II) nitrate

Copper(II) nitrateMagnesium nitrate

2Mg(NO3)2 → 2MgO + 4NO2 + O2

Iron(III) nitrate

4Fe(NO3)3 → 2Fe2O3 + 12NO2 + 3O2

Lead(II) nitrate

2Pb(NO3)2 → 2PbO + 4NO2 + O2Mercury(II) nitrate

Silver(I) nitrate

Aurum(II) nitrateSilver nitrate

2AgNO3 → 2Ag + 2NO2 + O2

Heating Effect on Sulphate Salts

Most sulphate salts do not decompose by heat. For instance, sodium sulphate, potassium sulphate, and calcium sulphate are not decomposable by heat.

Only certain sulphate salts are decomposed by heat when heated strongly.

For instance:

Strong heating of green crystal iron (II) sulphate will release steam, sulphur dioxide, sulphur trioxide and leave behind a reddish solid iron (III) oxide residue. The steam released comes from the hydrated water of the crystallize salt.

2FeSO4.7H2O → Fe2O3(p) + SO2(g) + SO3(g) + 14H2O(g)

Meanwhile, zinc sulphate, copper (II) sulphate, and iron (III) sulphate decompose when heated strongly to evolve sulphur (VI)oxide gas and form a metal oxide.

Example

Zinc sulphate

ZnSO4 → ZnO + SO3

Copper (II) sulphate

CuSO4 → CuO + SO3

Iron (III) sulphate

Fe2(SO4)3→ Fe2O3  + 3SO3

When ammonium sulphate is heated strongly, this white solid sublimate and is decomposed to form ammonia gas and sulphuric acid.

(NH4)2SO4 → NH3 + H2SO4