How many hydroxide/oxides/oxy anion of Cr & Mn are green in colour?
(a) $CrO_{5}$ (b) $CrO_{3}$ (c) $Cr_{2} O_{3}$ (d) $MnO_{2}$
(e) $Cr (OH)_{3}$ (f) $CrO_{4}^{2 -}$ (g) $MnO_{4}^{-}$ (h) $MnO_{4}^{2 -}$
(i) $Cr_{2} O_{7}^{2 -}$

Question

How many hydroxide/oxides/oxy anion of Cr & Mn are green in colour?

(a) $CrO_{5}$ (b) $CrO_{3}$ (c) $Cr_{2} O_{3}$ (d) $MnO_{2}$

(e) $Cr (OH)_{3}$ (f) $CrO_{4}^{2 -}$ (g) $MnO_{4}^{-}$ (h) $MnO_{4}^{2 -}$

(i) $Cr_{2} O_{7}^{2 -}$

TestHub · Accepted Answer

Colour of given compounds/ions:

CrO₅ → Blue

CrO₃ → Dark red

Cr₂O₃ → Green

MnO₂ → Black/Brown

Cr(OH)₃ → Green

CrO₄²⁻ → Yellow

MnO₄⁻ → Purple

MnO₄²⁻ → Green

Cr₂O₇²⁻ → Orange

Green coloured species are:

Cr₂O₃, Cr(OH)₃, MnO₄²⁻

Number of green coloured hydroxides/oxides/oxyanions = 3

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