MolSynapsequestion bank

MolSynapse / Question bank / d- and f-Block Elements / Important compounds: KMnO4 and K2Cr2O7

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3df106

Select the correct statements about potassium dichromate and the dichromate ion.

A $Cr X_{2} O X_{7} X^{2 -}$ has two $CrO X_{4}$ tetrahedra sharing one oxygen atom (a Cr-O-Cr bridge)
BAll Cr-O bond lengths in $Cr X_{2} O X_{7} X^{2 -}$ are exactly equal
CAcidification of yellow chromate gives orange dichromate without any change in oxidation state
DChromium in $Cr X_{2} O X_{7} X^{2 -}$ is $d^{0}$ , and the ion is diamagnetic

Answer: A, C, D

(a) True: two tetrahedra share a corner oxygen. (b) False: the bridging Cr-O bonds are longer than the terminal Cr-O bonds. (c) True:

2 CrO X_{4} X^{2 -} + 2 H X^{+} \to Cr X_{2} O X_{7} X^{2 -} + H X_{2} O

retains Cr(VI). (d) True: Cr(VI) has no

d

electrons, so the ion is diamagnetic.

Practice d- and f-Block Elements More on Important compounds: KMnO4 and K2Cr2O7

Previous questionNext question

More questions on Important compounds: KMnO4 and K2Cr2O7

0.490 g of K2Cr2O7 (molar mass 294 g mol^-1) is treated with excess KI in dilute H2SO4 and the liberated iodine is titrated with 0.100 M Na2... JEE Advanced level
0.800 g of pure ferrous oxalate, FeC2O4 (Fe = 56, C = 12, O = 16), is dissolved in dilute H2SO4. Both Fe^2+ and the oxalate are oxidised by ... JEE Advanced level
Select the correct statements about permanganate and manganate. JEE Advanced level
Acidified K2Cr2O7 (dilute H2SO4) is used in the following conversions. Which of them are correct? JEE Advanced level
Select the correct reactions of acidified KMnO4 (dilute H2SO4 medium). JEE Advanced level
Select the correct statements regarding the preparation of potassium permanganate. JEE Advanced level