Chemistry - Mole Concept Question with Solution | TestHub

$CaC{O}_3\left(s\right)\stackrel{\Delta }{\to }CaO\left(s\right)+C{O}_2\left(g\right)$

$MgC{O}_3\left(s\right)\stackrel{\Delta }{\to }MgO\left(s\right)+C{O}_2\left(g\right)$

Let the weight of $CaC{O}_3$ be $x gm$

$\therefore$ weight of $MgC{O}_3=\left(2.21-x\right) gm$

Moles of $CaC{O}_3$ decomposed = moles of $CaO$ formed

$\frac{x}{100}=$ moles of $CaO$ formed

$\therefore$ weight of $CaO$ formed $=\frac{x}{100}\times 56$
Moles of $MgC{O}_3$ decomposed = moles of $MgO$ formed

$\frac{\left(2.21-x\right)}{84}=$ moles of $MgO$ formed

$\therefore$  weight of $MgO$ formed $=\frac{2.21-x}{84}\times 40$ $\Rightarrow \frac{2.21-x}{84}\times 40+\frac{x}{100}\times 56=1.152$

$\therefore x=1.187g=$ weight of $CaC{O}_3$ and weight of $MgC{O}_3=1.023g$