Question

during oxidation of ferrous sulphate using mixture of dilute H2 S o4 and potassium dichromate Oxidation state of chromium change from​

Answer 1

Answer:+6 to +2

Explanation:

Answer 2

Oxidation state of chromium changes from​ +6 to +3

The reaction which happens between FeSO₄ and dilute H₂SO₄ and K₂Cr₂O₇ is shown below.

6FeSO₄ + K₂Cr₂O₇ + 7H₂SO₄ → K₂SO₄ + 3Fe₂(SO₄)₃ + Cr₂(SO₄)₃ + 7H₂O

Here, K₂Cr₂O₇ changes to Cr₂(SO₄)₃ at the end of the reaction.

The oxidation no. of K is +1 and for O it is -2 and for the SO₄ entity it is -2.

Let the oxidation no. of Cr in K₂Cr₂O₇ be x.

So, 2 + 2x + 7(-2) = 0

⇒ 2x - 14 + 2 = 0

⇒ 2x = 12

⇒ x = 12/2 = +6

Let the oxidation no. of Cr in Cr₂(SO₄)₃ be y.

So, 2y + 3(-2) = 0

⇒ 2y - 6  = 0

⇒ 2y = 6

⇒ y = 6/2 = +3