How nd' why metals react with water.........???
Metals form respective metal hydroxide and hydrogen gas when react with water.
Metal + Water ⇨ Metal hydroxide + Hydrogen
Most of the metals do not react with water. However, alkali metals react vigorously with water.
Different metals react with water at different rates.
K and Na react violently with cold water
Ca reacts with water, but less violently
Mg doesn’t react with cold water, but reacts with hot water
Al and Fe react only with steam
Other metals usually do not react with water or react very slowly.
Reaction of sodium metal with water: Sodium metal forms sodium hydroxide and liberates hydrogen gas along with lot of heat when reacts with water.
Na + H2O ⇨ NaOH + H2
Reaction of potassium metal with water: Potassium metal forms potassium hydroxide and liberates hydrogen gas along with lot of heat when reacts with water.
K + H2O ⇨ KOH + H2
Reaction of calcium metal with water: Calcium forms calcium hydroxide along with hydrogen gas and heat when reacts with water.
Ca + 2H2O ⇨ Ca(OH)2 + H2
Reaction of magnesium metal with water: Magnesium metal reacts with water slowly and forms magnesium hydroxide and hydrogen gas.
Mg + 2H2O ⇨ Mg(OH)2 + H2
When steam is passed over magnesium metal, magnesium oxide and hydrogen gas are formed.
Mg + H2O ⇨ MgO + H2
Reaction of aluminium metal with water: Reaction of aluminium metal with cold water is too slow to come into notice. But when steam is passed over aluminium metal; aluminium oxide and hydrogen gas are produced.
2Al + 3H2O ⇨ Al2O3 + 2H2
Reaction of zinc metal with water: Zinc metal produces zinc oxide and hydrogen gas when steam is passed over it. Zinc does not react with cold water.
Zn + H2O ⇨ ZnO + H2
Reaction of Iron with water: Reaction of iron with cold water is very slow and come into notice after a long time. Iron forms rust (iron oxide) when reacts with moisture present in atmosphere.
Iron oxide and hydrogen gas are formed by passing of steam over iron metal.
3Fe + 4H2O ⇨ Fe3O4 + 4H2
Other metals usually do not react with water or react very slowly.