Question

$2.76g$ of silver carbonate on being strongly heated yields a residue weighing:

• A. $2.16g$
• B. $2.48g$
• C. $2.32g$
• D. $2.64g$

Answer 1

Answer: (A)

$2.16g$

When silver carbonate is strongly heated, a residue of silver is obtained.
The reaction is as follows:

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

The molecular weight of silver carbonate and silver is $276$ g/mol and $108$ g/mol respectively.

Thus, when $276$ g (or $1$ mole) of silver carbonate is heated, $2\times 108=216$ g ($2$ moles) of silver is obtained.

When $2.76$ g of silver carbonate is heated, the amount of residue (silver) obtained is $\frac{216}{276}\times 2.76=2.16$ g.

Hence, the correct option is $A$