Question

$0.92$ g of ${Ag}_2{CO}_3$ is heated strongly beyond its melting point. After heating, the amount of residue is:

• A. $0.36$ g
• B. $0.39$ g
• C. $0.77$ g
• D. $0.72$ g

Answer 1

The correct option is D $0.72$ g

$A{g}_{2}C{O}_3\left(s\right)⟶2Ag\left(s\right)+C{O}_2\left(g\right)+\frac{1}{2}{O}_2\left(g\right)$

Molar mass of $A{g}_{2}C{O}_3=276g/mol$

$Ag=108g/mol$

So, $276g$ of $A{g}_{2}C{O}_3$ on heating gives $2\times 108g=216g$ of $Ag$ as residue.

Based on the stoichiometry of Ag (using mass by mass relationship),

So, $0.92g$ of $A{g}_{2}C{O}_3⟶\frac{216}{276}\times 0.92$

$=0.72g$ of $Ag$.

So, the correct answer is D.