Question

(a) Name the compound which is obtained from baking soda and is used to remove permanent hardness of water. (b) Write its chemical formula. (c) What happens when it is recrystallised from its aqueous solution?

Answer 1

Washing Soda,Na2CO3.10H2O. If recrystallised, crystals of washing soda are obtained.

Answer 2

Hlo mate,
Here is you answer,

$(a) \: the \: compound \: which \: is \: obtained \\ from \: baking \: soda \: and \: used \: to \: remove \\ permanent \: hardness \: of \: water \: is \\ \bf{washing \: soda \: ( \: sodium \: carbonate \\ decahydrate \: )}$

$(b) \: its \: chemical \: formula \: is \:$
$\bf{Na2CO3.10H2O}$

$(c) \: crystals \: of \: washing \: soda \: are \: obtained \\ when \: it \: is \: recrystallised \: from \: its \: aqueous \: solution.$

Hope this helps! ☺