Prepare $0\mathrm{.}01$M solution phosphate buffered saline $($PBS$)$ in $100$ml final volume:

In distilled H$2$O

NaCl: $0\mathrm{.}137$ M

KCl: $2\mathrm{.}7$ mM

Na$2$HPO$4$: $10\mathrm{.}0$ mM

KH$2$PO$4$: $1\mathrm{.}8$ mM

Identify the formula or molecular weight of each salt

Calculate the number of grams required to make a solution at the correct molarity

Hint: convert all measures to the same unit