Question

For 10^–2(M) H₃PO₃ solution which of the following relations is correct ?

• A. [H₃PO₃] + [$H_{2}PO_{3}^{–}$] + [$HPO_{3}^{2–}$] + [$PO_{3}^{2–}$] = 10^–2
• B. [H₃PO₃] + [$H_{2}PO_{3}^{–}$] + [$HPO_{3}^{2–}$] = 10^–2
• C. [$H_{2}PO_{3}^{–}$] + [$HPO_{3}^{2–}$] + [$PO_{3}^{3–}$] = 10^–2
• D. [H₃PO₃] + [$H_{2}PO_{3}^{–}$] + 2[H$PO_{3}^{2–}$] = 10^–2

Answer 1

Answer: (B)

$H₃PO₃$ + $H_{2}PO_{3}^{–}$ + $HPO_{3}^{2–}$ = 10^–2

Answer 2

H₃PO₃ $\rightleftarrows$ $H_{2}PO_{3}^{–}$ + H⁺

$H_{2}PO_{3}^{–}$ $\rightleftarrows$ $HPO_{3}^{2–}$+ H⁺

H₃PO₃ is a dibasic acid