1 Marks => CHAPTER-8 REDOX REACTIONS Questions Answers

ONE MARK QUESTIONS

Q.1. Define oxidation and reduction in terms of oxidation number.
Ans. Increase in Oxidation Number is Oxidation and decrease in Oxidation Number is called reduction.

Q.2. What is meant by disproportionation? Give one example.
Ans : In a disproportionation reaction an element simultaneously oxidized and
reduced.
0                               -3           +1
P₄ + 3OH^- +3H₂O→ PH₃ +3(H₂PO₂)^-

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

Q.4. Identify the central atom in the following and predict their O.S. HNO3
Ans: central atom:- N; O.S. +5


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

Q.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.


Q.7. How is standard cell potential calculated using standard electrode potential?
Ans: E⁰ cell = E⁰ cathode – E⁰ anode


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

Q.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.