What's the reaction between potassium iodide and sulfuric acid?

I tried looking it up on google, but I was getting mixed answers.

Is it going to be similar to the reaction between sulfuric acid and potassium bromide?

One was saying that KI and H2SO4 would produce potassium sulfate and hydrogen iodide. Another says, potassium hydrogensulfate and hydrogen iodide.

I guess the hydrogen iodide would then react with sulfuric acid to produce iodine,
sulfur dioxide, and water.

Reply 1

Chrisofsmeg

8

Several reactions occur:

KI(s) + H₂SO₄(l)

\longrightarrow

KHSO₄(s) + HI(g)

Iodide ions are strong reducing agents so they reduce the sulphur in sulphuric acid even further so that SO₂, S and H₂S (Hydrogen sulphide) are produced. The SO₄^2- ions are first reduced to SO₂, then to S, and then to H₂S.

8H⁺ + 8I^- + H₂SO₄(l)

\longrightarrow

H₂S(g) + 4H₂O(l) + 4I₂(s)

That's based on what the AQA textbook says and what I was taught anyway, there may be other products not included there.

The reaction is different to the reaction with Bromide ions because Iodide ions are stronger reducing agents. Hope that helps

(edited 12 years ago)

Reply 2

This Honest

3

Original post by Chrisofsmeg

Several reactions occur:

KI(s) + H₂SO₄(l)

\longrightarrow

KHSO₄(s) + HI(g)

Iodide ions are strong reducing agents so they reduce the sulphur in sulphuric acid even further so that SO₂, S and H₂S (Hydrogen sulphide) are produced. The SO₄^2- ions are first reduced to SO₂, then to S, and then to H₂S.

8H⁺ + 8I^- + H₂SO₄(l)

\longrightarrow

H₂S(g) + 4H₂O(l) + 4I₂(s)

That's based on what the AQA textbook says and what I was taught anyway, there may be other products not included there.

The reaction is different to the reaction with Bromide ions because Iodide ions are stronger reducing agents. Hope that helps