Question

Sodium bicarbonate on heating decomposes to form sodium carbonate, $ CO_{2} $ and water. If $0.2$ moles of sodium bicarbonate is completely decomposed, how many moles of sodium carbonate is formed?

• A. 0.1
• B. 0.2
• C. 0.05
• D. 0.025

Answer 1

Answer: (A)

$\underset{2\text{mol}}{2NaHCO_3} \xrightarrow{\Delta} \underset{1\text{mol}}{Na_2CO_3} + H_2O + CO_2$
$\because 2\, mol \, NaHCO _{3}$
on decomposition gives $=1 \,mol Na _{2} CO _{3}$
$\therefore 0.2 \,mol NaHCO _{3}$
on decomposition will give $=\frac{1}{2} \times 0.2$
$=0.1 \,mol \,Na _{2} CO _{3}$