$$\begin{gathered} \begin{array}{r}{\mathrm{C}}_7{\mathrm{H}}_6{\mathrm{O}}_3+{\mathrm{C}}_4{\mathrm{H}}_6{\mathrm{O}}_3⟶{\mathrm{C}}_9{\mathrm{H}}_8{\mathrm{O}}_4+{\mathrm{C}}_2{\mathrm{H}}_4{\mathrm{O}}_2\end{array} \\ salicylic acetic aspirin acetic acid \\ acid anhydride \end{gathered}$$

What is the percent yield if 0.85 g of aspirin is formed in the reaction of 1.00 g of salicylic acid with excess acetic anhydride?

Substance	Molar Mass
${\mathrm{C}}_7{\mathrm{H}}_6{\mathrm{O}}_3$	$138.12 g·{\mathrm{mol}}^{-1}$
${\mathrm{C}}_4{\mathrm{H}}_6{\mathrm{O}}_3$	$102.09 \mathrm{g}\cdot {\mathrm{mol}}^{-1}$
${\mathrm{C}}_9{\mathrm{H}}_8{\mathrm{O}}_4$	$180.15 \mathrm{g}\cdot {\mathrm{mol}}^{-1}$
${\mathrm{C}}_2{\mathrm{H}}_4{\mathrm{O}}_2$	$60.05 \mathrm{g}\cdot {\mathrm{mol}}^{-1}$