Reaction of iodide ions with concentrated sulfuric acid

Question 1

Reaction of iodide ions with concentrated sulfuric acid

The reaction of sodium iodide and concentrated sulfuric acid is:

Answer 1

H2SO4 (l) + NaI (s) → HI (g) + NaHSO4 (s)

Question 2

H2SO4 (l) + NaI (s) → HI (g) + NaHSO4 (s)

2HI (g) + H2SO4 (l) → I2 (g) + SO2 (g) + 2H2O (l)

what happens during this reaction to the next

Answer 2

Hydrogen iodide decomposes readily

Sulfuric acid oxidises the hydrogen iodide to form several products:

The concentrated sulfuric acid oxidises HI and is itself reduced to sulfur dioxide gas

Question 3

2HI (g) + H2SO4 (l) → I2 (g) + SO2 (g) + 2H2O (l)

6HI (g) + H2SO4 (l) → 3I2 (g) + S (s) + 4H2O (l)

what happens between these reactions

Answer 3

Iodine is seen as a violet/purple vapour in first reaction

The concentrated sulfuric acid oxidises HI and is itself reduced to sulfur:

Question 4

6HI (g) + H2SO4 (l) → 3I2 (g) + S (s) + 4H2O (l)

8HI (g) + H2SO4 (l) → 4I2 (g) + H2S (s) + 4H2O (l)

what happens between these reactions

Answer 4

Sulfur is seen as a yellow solid in first reaction

The concentrated sulfuric acid oxidises HI and is itself reduced to hydrogen sulfide:

Question 5

8HI (g) + H2SO4 (l) → 4I2 (g) + H2S (s) + 4H2O (l)

what happens this reaction

Answer 5

Hydrogen sulfide has a strong smell of bad eggs