Details

$$ Each $5$mL mixture should contain $150$mg of aspirin.

$$ Concentration of aspirin in aspirin mixture APF$12$ using the following units

$150$mg$/5$mL $=30$g$/$L and $30$g$/$L $=3\%$ w$/$v

Question

$1.$ Aspirin is a weak acid with a pKa of $3\mathrm{.}6$ and aqueous solubility $($saturation solubility$)3\mathrm{.}3$ g$/$L$.$ The MW of aspirin is $180$ g$/$mol$.$ Aspirin mixture APF$12$ is a suspension of aspirin with a concentration equal to your answer to details above.

$($a$)$ Calculate the pH of a saturated solution of aspirin in water.

M$=3\mathrm{.}3/180=0\mathrm{.}01833$

pH$=$pka $+$ log $([$A$-]/[$HA$])$

pH$=3\mathrm{.}6+$log $($x$/0\mathrm{.}01833)$

H$+=4\mathrm{.}6042$e$^-6$

pH $=$log $[4\mathrm{.}6042$e$^-6]=1\mathrm{.}9411$ is this correct method? or what is the correct method