Question

What happens to the crystals of sodium carbonate the left open in the air and heated write chemical equation to support your answer?

Answer 1

$\bold{SODIUM \: CARBONATE}$

Sodium carbonate or washing powder or soda ash , can be preapared in laboratory by

• First mixing the aqeous solution of calcium carbonate with sodium chloride .
• Stir the solution properly.
• Filter the solution formed with the help of filter paper.
• Now heat the solution in evaporating dish ,.
• After some time time it will be noticed that white crystals are formed at the surface , the crystals obtained are of sodium carbonate.
• During crystallisation , 10 water molecules enters in the each  crystals of sodium carbonate in lose chemical combination which is known as the water of crystallisation

• When  sodium carbonate is  left open  in air

When sodium carbonate is exposed to the air , it changes into white anyhdrous powder as it loses its water molecule of water of crystallisation by efflorescence.

• Effloroscene is the phenomenon in which hydrated salts loses their water of crystallisation  partially or completely when exposed to atmosphere

$Na_2CO_3.10H_2O \longrightarrow Na_2CO_3 +10H_2O$

Answer 2

Answer:

Here!

Explanation:

When crystals of washing soda, i.e., Na2CO3. 10H2O is left open in the dry air, it loses water of crystallization.

When it is heated it undergoes a thermal decomposition reaction. This takes place above 500 degree C.  The reaction of decomposition is Na2CO3(s)→Na2O(s)+CO 2(g)