A student must make a buffer solution with a $pH$ of $5\mathrm{.}50.$

Determine which weak acid is the best option to make a buffer at the specified $pH.$

ammonium citrate, $K_a=4\mathrm{.}06{10}^{-7},2\mathrm{.}00M$

acetic acid, $K_a=1\mathrm{.}75{10}^{-5},5\mathrm{.}00M$

propionic acid, $K_a=1\mathrm{.}34{10}^{-5},3\mathrm{.}00M$

formic acid, $K_a=1\mathrm{.}77{10}^{-4},2\mathrm{.}00M$

Determine which conjugate base is the best option to make a buffer at the specified pH$.$

sodium acetate trihydrate, $C{H}_3\frac{C}{O}ONa*3H_{2}O$

sodium propionate, $C{H}_{3}C{H}_2\frac{C}{O}ONa$

sodium citrate dihydrate, $C_6{H}_5{O}_{7}N{a}_3*2H_{2}O$

sodium formate, $H\frac{C}{O}ONa$

The final volume of buffer solution must be $100\mathrm{.}00mL$ and the final concentration of the weak acid must be $0\mathrm{.}100M.$

Based on this information, what mass of solid conjugate base should the student weigh out to make the buffer solution with a pH of $5\mathrm{.}50?$

mass $=$

g

Based on this information, what volume of acid should the student measure to make the buffer solution?