What is the $pH$ of a solution of $0\mathrm{.}02M$ of $N{a}_{2}HP{O}_4?$ The stepwise dissociation of

What is the pH of a solution of $0\mathrm{.}02M$ of $N{a}_{2}HP{O}_4?$ The stepwise dissociation of $H_{3}P{O}_4(aq)$ is described using these three acidity constants: $p{K}_{a1}=2\mathrm{.}1,p{K}_{a2}=7\mathrm{.}4,p{K}_{23}=12\mathrm{.}4.(17$ pts$)$

a$)$ Start by showing a speciation diagram.

b$)$ Write down the mass$-$balance, proton$-$balance, and charge$-$balance equations.

c$)$ What is the speciation of this solution at $pH=4?$

d$)$ What is the $pH$ after you make up this solution to be $0\mathrm{.}02M$ of $N{a}_{2}HP{O}_4?$

e$)$ Is this system open or closed with respect to phosphate? Why?$H_{3}P{O}_4(aq)$ is described using these three acidity constants: $p{K}_{21}=2\mathrm{.}1,p{K}_{a2}=7\mathrm{.}4,p{K}_{a3}=12\mathrm{.}4.(17$ pts$)$

a$)$ Start by showing a speciation diagram.

b$)$ Write down the mass$-$balance, proton$-$balance, and charge$-$balance equations.

c$)$ What is the speciation of this solution at $pH=4?$

d$)$ What is the $pH$ after you make up this solution to be $0\mathrm{.}02M$ of $N{a}_{2}HP{O}_4?$

e$)$ Is this system open or closed with respect to phosphate? Why?

Thermodynamic Data from Woods and Garrels $(1987)$: 'Thermodvnamic Values at Low Temperature...$\text{'}$

$$table$[[$Formula$,H(k\frac{J}{m}ol),G(k\frac{J}{m}ol),S(\frac{J}{d}eg)$