Chapter 13: oxidation & reduction

Question 1

4 definition of oxidation & reduction

Answer 1

oxidation
1. gains oxygen
2. loses hydorgen
3. loses electrons
4. ↑ in O.S.

reduction
1. loses oxygen
2. gains hydrogen
3. gains electrons
4. ↓ in O.S.

Question 2

test for O.A.

Answer 2

test: add aq. potassium iodide ( R.A. ) to the unknown solution
observe: if colourless KI turns brown, O.A. is present
exp.: iodide ions are oxidized to iodine by O.A.

Question 3

test for R.A.

Answer 3

test: add aq. potassium manganate(VII) ( O.A. ) to the unknown solution
observe: if purple KMnO₄ turns colourless, R.A. is present
exp.: manganate(VII) ions are reduced to managanese(II) ions by R.A.