Redox Reactions

Question 1

Explain the meaning of the term oxidisation state

Answer 1

The charge on the ion

Question 2

When concentrated sulfuric acid is added to potassium iodide solid sulfur and a black solid are formed

Identify the black solid

Answer 2

Idoine is the black solid

Question 3

When iodide ions react with concentrated sulfuric acid in a different redox reaction the oxidisation state of sulphur changes from 6 to -2 the reduction product of this reaction is a poisonous gas that has an unpleasant smell. Identify this gas 

Answer 3

Hydrogen sulphide

Question 4

State what is observed when concentrated ammonia solution is added to the yellow precipitate 

Answer 4

Stays the same

Question 5

State why the silver nitrate is acidified when testing for iodide ions ( reduced form of iodine)

Answer 5

It remove the ions that would interfere with the test

Question 6

Explain why idodide ions react differently from chloride ions

Answer 6

Iodide ions are larger and have more shielding so it loses its electrons more easily