You will be provided with $1\mathrm{.}00$ M H$3$PO$4,0\mathrm{.}50$ M Na$2$HPO$4$ and $0\mathrm{.}75$ M NaH$2$PO$4.$ Using the Henderson$-$Hasselbalch equation, calculate how much of each you will need to make $200$ mL of a $500$ mM NaPO$4$ solution at pH $6\mathrm{.}0.$ You must show your work to get the credit for this calculation$/$prelab$.*$Note: you may not need all of these phosphate solutions.