Question

Which reaction involves neither oxidation nor reduction?
(a) CrO₄² Cr₂O₇² (b) Cr CrCl₃
(c) Na Na (d) 2S₂O₃² S₄O₆

Answer 1

Answer:

c

because both has same they don't have any oxidation and reduction

Answer 2

Question - Which of the following reaction involves neither oxidation nor reduction

(a) CrO42– → Cr2O72–

(b) Cr → CrCl3

(c) Na → Na+

(d) 2S2O32– → S4O62–

Answer - No oxidation and no reduction can be seen in -

(a) CrO42– → Cr2O72–

In CrO42–, oxidation number of chromium is calculated as -

X - 8 = -2

X = 6.

For Cr2O72–, oxidation number of chromium will be calculated as -

2x - 14 = -2

2x = 12

X = 6.

Hence, no change in oxidation number is seen.

Cr has zero oxidation number, while CrCl3 in this compound chromium has oxidation number equal to +3.

In Na and Na+, change in oxidation number is +1.

Here, in 2S₂O₃² oxidation number is - +2, while in S₄O₆ oxidation number changes to +3.

Hence, no change in oxidation number is seen only in option

(a) CrO42– → Cr2O72–