In a 0.010M solution of oxalic acid, H2C2O4, K1=5.9× 10-2, Ka2=6.4× 10-5, the species present in the lowest concentration is

Question

In a 0.010M solution of oxalic acid, H2C2O4, K1=5.9× 10-2, Ka2=6.4× 10-5, the species present in the lowest concentration is (A)  H2C2O4  (B)  H3O+  (C)  HCr2O4-  (D)  CrO42-

Tardigrade Admin · Accepted Answer

Due to very small value of Ka2, the second ionisation will be very less and in solution, oxalate ion (Cr2O4)2- will be at lowest concentration.

Q. In a 0.010M solution of oxalic acid, $H_{2} C_{2} O_{4},$ $K_{1} = 5.9 \times 10^{- 2},$ $K_{a_{2}} = 6.4 \times 10^{- 5},$ the species present in the lowest concentration is

$H_{2} C_{2} O_{4}$

$H_{3} O^{+}$

$H C r_{2} O_{4}^{-}$

$C r O_{4}^{2 -}$

Due to very small value of $K_{a_{2}},$ the second ionisation will be very less and in solution, oxalate ion $(C r_{2} O_{4})^{2 -}$ will be at lowest concentration.

Q. In a 0.010M solution of oxalic acid, H2​C2​O4​, K1​=5.9×10−2, Ka2​​=6.4×10−5, the species present in the lowest concentration is

H2​C2​O4​

H3​O+

HCr2​O4−​

CrO42−​