Thermal decomposition of Metal Carbonates
A number of metal carbonates can be thermally decomposed, including calcium carbonate, magnesium carbonate, lithium carbonate and...
CuCO3 CuO + CO2
ZnCO3 ZnO + CO2
(white) (yellow when hot
white when cold)
Comp of Dry Air
Other gases including CO2 0.04%
Metals usually on heating are oxidised by reacting with oxygen in the air to produce metal oxide:
Most metals react with acids forming a salt and hydrogen. Effervesence is observed as the reaction proceeds
Displacement Reactions of Metals
More reactive metals displace less reactive metals from the compounds
Reactive metals such as potassium,sodium and lithium react vigorously with water forming the metal hydroxide and hydrogen.
Sodium floats on water, moves over the surface of water and effervesces. In addition to these observations if potassium is used a lilac flame is observed. The reaction is highly exothermic causing the metal to melt and become spherical
A very exothermic reaction is called a thermit reaction.
This is used to produce molten iron to join railway lines together. All displacement reactions are exothermic. The greater the difference in reactivity of the metal the more exothermic the reaction and the greater the tempertaure rise.