Question

When $4.215$ g of metalic carbonate was heated in a hard glass tube, the $C{O}_2$ evolved was found to be measured $1336$ mL at ${27}^{o}C$ and $700$ mm pressure. If $X$ g is the equivalent weight of the metal, then find the value of $1000X$.

• A. 12188
• B. 12000
• C. 12500
• D. none of the above

Answer 1

Answer: (A)

12188

$PV=nRT=\frac{W}{Mw}RT$
$\therefore \frac{700}{760}\times \frac{1336}{1000}=\frac{W}{44}\times 0.0821\times 300$
or, $W=2.198gC{O}_2$
The molecular mass of any metal carbonate is $2E+60$, where E is the equivalent mass of the metal.
So, $\frac{2E+60}{4.215}=\frac{44}{2.198}$
or, $E=12.188g$