Answer: The concentration of unknown phosphoric acid solution is 0.034 M
Explanation:
To calculate the concentration of acid, we use the equation given by neutralization reaction:
[tex]n_1M_1V_1=n_2M_2V_2[/tex]
where,
[tex]n_1,M_1\text{ and }V_1[/tex] are the n-factor, molarity and volume of acid which is [tex]H_3PO_4[/tex]
[tex]n_2,M_2\text{ and }V_2[/tex] are the n-factor, molarity and volume of base which is NaOH.
We are given:
[tex]n_1=3\\M_1=?M\\V_1=34.57mL\\n_2=1\\M_2=0.127M\\V_2=28.2mL[/tex]
Putting values in above equation, we get:
[tex]3\times M_1\times 34.57=1\times 0.127\times 28.2\\\\M_1=\frac{1\times 0.127\times 28.2}{3\times 34.57}=0.034M[/tex]
Hence, the concentration of unknown phosphoric acid solution is 0.034 M
