Chemical Properties of Metals
● Alkali metals (Li, Na, K, etc) react vigorously with water and oxygen or air.
● Mg reacts with hot water.
● Al, Fe and Zn react with steam.
● Cu, Ag, Pt, Au do not react with water or dilute acids.
Reaction of Metals with Oxygen (Burnt in Air)
Metal oxide is formed when metals are burned in air and react with oxygen in the air. Metal oxides are a type of basic material found in nature. They change the colour of red litmus to blue. To avoid reactions with oxygen, moisture, and carbon dioxide in the air, sodium and potassium metals are kept in kerosene oil.
Metal + Oxygen→ Metal oxide (basic)
● Na and K are kept immersed in kerosene oil as they react vigorously with air and catch fire.
4K(s)+O2(g)→2K2O(s) (vigorous reaction)
● Mg, Al, Zn, Pb react slowly with air and form a protective layer that prevents corrosion.
2Mg(s)+O2(g)→2MgO(s) (Mg burns with white dazzling light)
4Al(s)+3O2(g)→2Al2O3(s)
● Silver, platinum and gold don’t burn or react with air.