chemistry

REDOX REACTIONS

ONE MARK QUESTIONS

1.     Define oxidation and reduction in terms of oxidation number.

a.     Ans Increase in Oxidation Number is Oxidation and decrease in Oxidation Number is called reduction.

2.     What is meant by disproportionation? Give one example.

a.     Ans : In a disproportionation reaction an element simultaneously oxidized and

b.     reduced.

c.      P₄+ 3OH^- +3H₂O→ PH₃+3H₂PO₂^-

3.     What is O.N. of sulphur in H₂SO₄?Ans: +6

4.     Identify the central atom in the following and predict their O.S. HNO₃

Ans: central atom:-  N; O.S.  +5

5.     Out of Zn and Cu which is more reactive? Ans: Zn.

6.     What is galvanization?

Ans: Coating of a less reactive metal with a more reactive metal e.g.- coating of iron surface with Zn to prevent rusting of iron.

7.     How is standard cell potential calculated using standard electrode potential?

Ans: E⁰_cell= E⁰_cathode– E⁰_anode

8.     What is O.S. of oxygen in H₂O₂? Ans: - -1.

9.     The formation of sodium chloride from gaseous sodium and gaseous chloride is a redox process justify.

Ans: Na atom get oxidize and Cl is reduced.