Hi$,$ i need help with following problem:

How much ferric chloride $($mg$/$L$)$ is needed to remove soluble phosphate $($PO$43-)$ from wastewater, when the soluble phosphate content of the wastewater is $5$ g P$/$m$3$ and the target concentration of soluble phosphate is $0\mathrm{.}1$ mg P$/$L$?$ How much ferric chloride is needed $($L$/$d$)$ at the treatment plant per day, when the flow is $3800$ m$3/$d$?$ Ferric chloride is dosed as a $37$ wt$\%$ solution and has a density of $1\mathrm{.}35$ kg$/$L