MCQs on Redox Reaction and Method for Balancing Redox Reaction
1. Which of the following represents a redox reaction?
(a)NaOH + HCl → NaCl + H2O
(b)BaCl2 + H2SO4 → BaSO4 + 2HCl
(c)CuSO4 + 2H2O → Cu(OH)2 + H2SO3
(d)Zn + 2HCl → ZnCl2 + H2
Answer:::: (d)
2. Which reaction involves neither oxidation nor reduction?
(a)CrO42- -→ Cr2O72-
(b)Cr → CrCl3
(c)Na → Na+
(d)2S2O32- → S4O62-
Answer:::: (a)
3. Zn gives H2 gas with H2SO4 and HCl but not with HNO3 because
(a)Zn acts as an oxidising agent when it reacts with HNO3
(b)HNO3 is a weaker acid than H2SO4 and HCl
(c)In electrochemical series, Zn is above hydrogen
(d)NO3– is reduced in preference to hydronium ion
Answer:::: (d)
4. A compound of Xe and F is found to have 53.5% of Xe. What is the oxidation number of Xe in this compound?
(a)-4
(b)0
(c)+4
(d)+6
Answer:::: (d)
5. A solution contains Fe2+, Fe3+ and I– ions. This solution was treated with iodine at 35oC. Eo for Fe3+/Fe2+ is 0.77V and Eo for I2/2I– = 0.536V. The favourable redox reaction is
(a)I2 will be reduced to I–
(b)there will be no redox reaction
(c)I– will be oxidised to I2
(d)Fe2+ will be oxidised to Fe3+
Answer:::: (c)
6. One mole of N2H4 loses 10 moles of electrons to form a new compound y. Assuming that all nitrogen appears in the new compound, what is the oxidation state of nitrogen in y.
(a)-1
(b)-3
(c)+3
(d)+5
Answer:::: (c)
7. The equivalent mass of oxidising agent in the following reaction is
SO2 + 2H2S → 3S + 2H2O
(a)32
(b)64
(c)16
(d)8
Answer:::: (c)
8. In the reaction
3Br2 + 6CO32- + 3H2O → 5Br– + BrO3– + 6HCO3–
(a)bromine is oxidised and carbonate is reduced
(b)bromine is reduced and water is oxidised
(c)bromine is neither reduced nor oxidised
(d)bromine is both reduced and oxidised
Answer:::: (d)
9. Which of the following cannot function as an oxidising agent?
(a) I–
(b)Si(s)
(c)NO3–(aq)
(d)Cr2O72-
Answer:::: (a)
10. The oxidation number of Pt in [Pt(C2H4)Cl3]– is
(a)+1
(b)+2
(c)+3
(d)+4
Answer:::: (b)
