Question

Which of the following ion in aqueous medium has orange colour?

• A. $C{{r}^{+3}}$
• B. $C{{r}_{2}}O_{7}^{2-}$
• C. $MnO_{4}^{-}$
• D. $MnO_{4}^{2-}$

Answer 1

Answer: (B)

$C{{r}_{2}}O_{7}^{2-}$

Answer 2

Dichromate ion $(C{{r}_{2}}O_{7}^{2-})$ has orange colour. The colour of chromium ion $(C{{r}^{3+}}),$ permaganate ion $(MnO_{4}^{-})$ and maganate ion $(MnO_{4}^{2-})$ are green, violet and green respectively.