Pupil sheet · Redox
Redox — return questions
Name ______________________ Date ____________
Use one to two weeks after the lessons. Keep the notes and the lesson closed.
1. identify
Iron(II) oxide is heated with carbon: FeO + C → Fe + CO. Fill in the gaps. In iron(II) oxide, the oxidation number of iron is (1) ___. Iron(II) oxide (2) ___ oxygen, so it is (3) ___. Carbon (4) ___ oxygen, so it is (5) ___.
(1)
(2)
(3)
(4)
(5)
2. identify
Supplement. Substance X oxidises sulfite ions, SO32−, to sulfate ions, SO42−. Oxygen has the oxidation number −2. Which row is correct?
| Row | Sulfur in SO32− | X is |
|---|---|---|
| A | +4 | reduced |
| B | +4 | oxidised |
| C | +6 | reduced |
| D | +6 | oxidised |
Circle one answer.
- A
- B
- C
- D
3. identify
Supplement. Solution S turns aqueous potassium iodide brown. Solution T turns acidified potassium manganate(VII) from purple to colourless. Which row is correct?
| Row | S is | T is |
|---|---|---|
| A | an oxidising agent | a reducing agent |
| B | a reducing agent | an oxidising agent |
| C | an oxidising agent | an oxidising agent |
| D | a reducing agent | a reducing agent |
Circle one answer.
- A
- B
- C
- D