Question 1 What happens when potassium react with water?
Question 2 What happens when sodium react with water?
Question 3 What happens when aluminium react with water?
Question 4 What happens when zinc react with water?
Reaction of Metals with Water
Metals react with water to form hydroxide, hydrogen gas and heat is evolved.
2K +2H2O ———-> 2KOH + H2 +heat
cold
2Na + 2H2O ———-> 2NaOH + H2 +heat
cold
2Na (s) + 2 H20 (l) —-> 2 NaOH (aq) + H2 (g) +heat
Ca(s) + 2 H20 (l) —–> Ca(OH)2 (aq) + H2 (g)
Mg(s) + 2 H20 (l) —–> Mg(OH)2 (aq) + H2 (g)
2Al (s) + 3 H20 (l) —–> Al2O3 (s) + 3 H2 (g)
Zn (s) + H20 (l) —–> ZnO(s) + H2 (g)
3 Fe (s) + 4 H20 (l) —–> Fe3O4 (s) + 4 H2 (g)
Zn, Al, Fe react with water to form metal oxide.
The reaction of Ca with water is less violent. The heat evolved in not sufficient for hydrogen to catch fire.
Ca starts floating because bubbles of hydrogen gas formed stick to the surface of metal.