## Chemistry: The Central Science (13th Edition)

The ligand $(C_{2}O_{4})_{3}$ that surround the central metal atom $V$ are 3, but since $(C_{2}O_{4})_{3}$ is a bidentate ligand, the coordination number is 6. ($3 \times 2 =6$) Let us suppose the oxidation number of $V$ is X. To find the oxidation number, we sum the known oxidation numbers and equal it to the charge on the complex. Also, $(C_{2}O_{4})_{3}= 3 \times (-2)$ $K_{3} = 3\times(+1)$ The overall charge is zero on the complex, thus: $3\times (+1) +X + 3 \times (-2)= 0$ $+3+X-6=0$ $X=+6-3$ $X=+3$ The oxidation number of $V$ is +3