$K _{ a_1,}, K _{ a_2 }$ and $K _{ a_3}$ are the respective ionization constants for the following reactions $(a), (b),$ and $(c)$.

$(a)$ $H _{2} C _{2} O _{4} \rightleftharpoons H ^{+}+ HC _{2} O _{4}^{-}$

$(b)$ $HC _{2} O _{4}^{-} \rightleftharpoons H ^{+}+ HC _{2} O _{4}^{2-}$

$(c)$ $H _{2} C _{2} O _{4} \rightleftharpoons 2 H ^{+}+ C _{2} O _{4}^{2-}$

The relationship between $K_{a_{1}}, K_{ a _{2}}$ and $K_{ a _{3}}$ is given as

• A

  $K_{ a _{3}}= K _{ a _{1}}+ K _{ a _{2}}$

• B

  $K_{a_{a_{3}}}=K_{a_{1}}-K_{a_{2_{2}}}$

• C

  $K _{ a _{1}}= K _{ z _{1}} / K _{ s _{2}}$

• D

  $K _{ a _{3}}= K _{ a _{1}} \times K _{ s _{2}}$