Question

What weight of $CaCO_3$ must be decomposed to produce the sufficient quantity of carbon dioxide to convert $21.2\, kg$ of $Na_2CO_3$ completely in to $NaHCO_3$. [Atomic mass $Na = 23$, $Ca = 40$] $CaCO_3 \to CaO + CO_2$ $Na_2CO_3 + CO_2 + H_2O \to 2NaHCO_3$

• A. $100 \,kg$
• B. $20\, kg$
• C. $120\, kg$
• D. $30\, kg$

Answer 1

Answer: (B)

$20\, kg$

Answer 2

Moles of $Na_{2}CO_{3}= \frac{21.2\,\times\,10^{3}}{106} = 200$ So moles of $CO_{2} = 200$ & so moles of $CaCO_{3}$ reqd $= 200$ $\therefore$ wt of $CaCO_{3}$ reqd $= 200 \,\times\, 100 = 20\, kg$