Question

(i)Name the compound which is obtained from baking soda and is used to remove permanent hardness of water. (ii) Write its chemical formula (iii) What happens when it is re-crystallized from its aqueous solution?

Answer 1

Washing soda is obtained from baking soda and is used to remove permanent hardness of water.

Chemical formula- Na{3} CO{2} .10H{2}O

Anhydrous sodium carbonate becomes hydrated when it is recrystallized from its aqueous solution.

Answer 2

Answer:

(I) THE NAME OF THE COMPOUND IS WASHING SODA (NA2CO3. 10H2O). IN CRYSTALLISATION FORM IT POSSESSES 10 MOLECULES AND DUE TO THIS IT IS KNOWN AS SODIUM CARBONATE DECAHYDRATE & USED TO REMOVE PERMANENT HARDNESS OF WATER

(II) WHEN RECRYSTALLISATION OF SODIUM CARBONATE GIVES WASHING SODA.

THE FOLLOWING EQUATION STATES THE RECRYSTALLISATION OF WASHING SODA :

NA2CO3+10H20-NA2CO3. 10H20