A sample of $2-$naphthol $($C$10$H$7$OH; M $=144\mathrm{.}18$ g$/$mol$)$ is contaminated with a small amount of lithium bromide.

a small amount of lithium bromide. From the analysis of the combustion products

The combustion products analysis showed that the sample analyzed had $77\mathrm{.}48\%$ carbon and $5\mathrm{.}170\%$ hydrogen.

$5\mathrm{.}170\%$ hydrogen. Assuming that the only compounds present in the sample are

$2-$naphthol and lithium bromide, determine the percent purity $($by mass$)$ of the sample.

sample.