PYQ NEET- Organic Chemistry Some Basic Principles L-7

Question: The right option for the mass of $\mathrm{CO}_2$ produced by heating $20 \mathrm{~g}$ of $20 %$ pure limestone is#

(Atomic mass of $\mathrm{Ca}=40$ ) $$ \left[\mathrm{CaCO}_3 \stackrel{1200 \mathrm{~K}}{\longrightarrow} \mathrm{CaO}+\mathrm{CO}_2\right] $$

A) $1.76 \mathrm{~g}$

B) $2.64 \mathrm{~g}$

C) $1.32 \mathrm{~g}$

D) $1.12 \mathrm{~g}$

Answer: $1.76 \mathrm{~g}$#

Solution:#

Weight of impure limestone $=20 \mathrm{~g}$ Weight of pure limestone $\left(\mathrm{CaCO}3\right)=20 %$ of $20 \mathrm{~g}$ $$ \begin{aligned} & =\frac{20}{100} \times 20 \ & =4 \mathrm{~g} \end{aligned} $$ $$ \begin{aligned} & \mathrm{n}{\mathrm{CaCO}3}=\frac{4}{100}=0.04 \ & \text { Image } \ & \mathrm{n}{\mathrm{CO}2}=0.04 \ & \mathrm{~W}{\mathrm{CO}_2}=0.04 \times 44 \ & =1.76 \mathrm{~g} \end{aligned} $$