Question

IMPORTANT!!!

WHY K2Cr2O7 has oxidation number 2x(+6)
why on right side 6 electron are less

explain​

Answer 1

Answer:

ok first

oxidation number is increased to 8

Answer 2

So in this you are to find the oxidation number of Cr in K2Cr2O7

Note that  a neutral compound has a 0 overall oxidation number.

First you need to find out the individual oxidation numbers of each element in K2Cr2O7

Let oxidation number of Cr2 be 2x.

K has +1 oxidation number and there are 2 atoms , so net oxi. = +2

O has -2 oxidation number and there are 7 atoms , so net oxi. = -14

therefore overall oxidation of compound

2x + 2 - 14 = 0

2x = 12

x = +6    --(1)

Now , RHS

Same procedure as above.

Let Oxidation number of Cr2 be 2x.

You can calculate the oxidation of SO4 , rather remember the value i.e. = -2

Now oxidation number of SO4 is -2 , net oxi. = -6

therefore overall oxidation of compound

2x - 6 = 0

2x = 6

x = 3    --(2)

Note that , in eqn. (1) and (2) this is the oxidation number of one single Cr atom.

The overall decrease in oxidation number of Cr is

12 - 6 = 6

That is why there is a decrease of 6 in o.s

hope you understand

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