Washing soda $$(Na_2CO_3·10H_2O)$$​ is obtained from which compound in the Solvay process?

Correct option is C

The correct answer is option (c) Sodium bicarbonate

Washing soda $$(\text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O})$$​ is obtained from sodium bicarbonate $$(\text{NaHCO}_3)$$​ in the Solvay process.

Reaction:

Sodium bicarbonate is first heated to form sodium carbonate:

​$$2\text{NaHCO}_3 \xrightarrow{\Delta} \text{Na}_2\text{CO}_3 + \text{H}_2\text{O} + \text{CO}_2$$​​

Then, sodium carbonate is recrystallized to form washing soda:

​$$\text{Na}_2\text{CO}_3 + 10\text{H}_2\text{O} \rightarrow \text{Na}_2\text{CO}_3 \cdot 10\text{H}_2\text{O}$$​​