Name: Redox Reactions as a Basis for Titration
Uploaded: 2019-07-19
Duration: 7 min 17 s
Description: This video will help us learn about how redox indicators like potassium permanganate or diphenylamine are used to indicate the completion of a redox reaction...

Question

Calculate the oxidation number of sulphur, chromium and nitrogen in

H_{2} {SO}_{5}

,

{Cr}_{2} {O_{7}}^{2 -}

and

{NO}_{3}^{-}

. Suggest structure of these compounds.

Accepted Answer

$H_{2} {SO}_{5}$

Let assume oxidation number of $S$ is $x$ .

We know that,

$H_{2} {SO}_{5}$ contains one peroxide linkage. So that, the oxidation number of oxygen atom involved in peroxide linkage is $- 1$ .

Oxidation number of $H$ $= + 1$

Oxidation number of $O = - 2$ (for normal oxygen atoms).

Hence, the oxidation number of $S$ is

$2 (+ 1) + 1 (x) + 3 (- 2) + 2 (- 1) = 0 \Rightarrow 2 + x - 6 - 2 = 0 \Rightarrow x = + 6$

The structure of $H_{2} {SO}_{5}$ is shown as follows:

Therefore, the oxidation number of $S$ is $+ 6$ .

${Cr}_{2} {O_{7}}^{2 -}$

Let assume oxidation number of $Cr$ is $x$ .

We know that,

Oxidation number of $O = - 2$

Then we have

$2 (x) + 7 (- 2) = - 2 \Rightarrow 2 x - 14 = - 2 \Rightarrow 2 x = + 12 x = + 6$

Here, there is no fallacy about the oxidation number of $Cr$ in ${Cr}_{2} {O_{7}}^{2 -}$ .

The structure of ${Cr}_{2} {O_{7}}^{2 -}$ is shown as follows:

Here, each of the two $Cr$ atoms exhibits the oxidation number of $+ 6$ .

${NO}_{3}^{-}$

Let assume oxidation number of $N$ is $x$ .

We know that,

Oxidation number of $O = - 2$

Then we have

$1 (x) + 3 (- 2) = - 1 \Rightarrow x - 6 = - 1 \Rightarrow x = + 5$

Here, there is no fallacy about the oxidation number of $N$ in ${NO}_{3}^{-}$

The structure of ${NO}_{3}^{-}$ is shown as follows:

The $N$ atom exhibits the oxidation number of $+ 5$ .

Calculate the oxidation number of sulphur, chromium and nitrogen in $H_{2} {SO}_{5}$ , ${Cr}_{2} {O_{7}}^{2 -}$ and ${NO}_{3}^{-}$ . Suggest structure of these compounds.

Important Questions on Stoichiometry

Learn and Prepare for any exam you want !

Calculate the oxidation number of sulphur, chromium and nitrogen in H2SO5, Cr2O72- and NO3-. Suggest structure of these compounds.

Important Questions on Stoichiometry

Learn and Prepare for any exam you want !

Calculate the oxidation number of sulphur, chromium and nitrogen in $H_{2} {SO}_{5}$ , ${Cr}_{2} {O_{7}}^{2 -}$ and ${NO}_{3}^{-}$ . Suggest structure of these compounds.