# Chemistry Class 11 NCERT Solutions: Chapter 8 Redox Reactions Part 4

**Chemistry Class 11 NCERT Solutions Chapter 8 Redox Reactions Part 4**

Q: 5. Calculate the oxidation number of sulphur, chromium and nitrogen in

. Suggest structure of these compounds. Count for the fallacy.

Answer:

(i)

However, the O.N. of S cannot be +8. S has six valence electrons. Therefore, the O.N. of

S cannot be more than +6.

The structure of is shown as follows:

Now,

Therefore, the O.N. of S is +6.

(ii)

Here, there is no fallacy about the O.N. of Cr in .

The structure of is shown as follows:

Here, each of the two Cr atoms exhibits the O.N. of +6.

(iii)

Here, there is no fallacy about the O.N. of N in

The structure of is shown as follows:

Image:

The N atom exhibits the O.N. of +5.