Q1. In the reaction 2Fe2O3 + 3C → 4Fe + 3CO2, what is being reduced? (2020) 2020
Solution:
Fe2O3 is reduced to Fe, as it gains electrons during the reaction.
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Q2. What is the product of the reduction of Cr2O7^2- in acidic medium?
Solution:
In acidic medium, Cr2O7^2- is reduced to Cr^3+.
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Q3. What is the oxidation state of sulfur in H2SO4? (2021) 2021
Solution:
In H2SO4, the oxidation state of sulfur is +6. Each hydrogen is +1 and each oxygen is -2, leading to the equation: 2(+1) + x + 4(-2) = 0, solving gives x = +6.
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Q4. What is the oxidation state of chlorine in NaClO3? (2022) 2022
Solution:
In NaClO3, the oxidation state of chlorine is +5. Sodium is +1 and each oxygen is -2, leading to the equation: +1 + x + 3(-2) = 0, solving gives x = +5.
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Q5. Which of the following reactions is a reduction? (2020)
Solution:
In the reaction Fe2O3 + 3CO → 2Fe + 3CO2, iron (Fe) is reduced as it gains electrons from carbon monoxide (CO).
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Q6. In the reaction 2Fe + 3Cl2 → 2FeCl3, which element is oxidized?
Solution:
Iron (Fe) is oxidized as it loses electrons to form FeCl3.
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Q7. What is the oxidation state of nitrogen in NH4+? (2020) 2020
Solution:
In NH4+, nitrogen has an oxidation state of -3. Each hydrogen is +1, leading to the equation: x + 4(+1) = +1, solving gives x = -3.
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Q8. In the redox reaction 2MnO4- + 5C2O4^2- + 16H+ → 2Mn^2+ + 10CO2 + 8H2O, what is the oxidation state of carbon in C2O4^2-?
Solution:
In C2O4^2-, the oxidation state of carbon is +3.
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Q9. In the reaction 3H2 + N2 → 2NH3, which element is reduced? (2022)
Solution:
N2 is reduced to NH3 as it gains electrons.
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Q10. In the redox reaction 2Ag+ + Zn → 2Ag + Zn2+, which species is oxidized? (2021)
