Redox reactions practice · Mixed difficulty

Option C (5) is correct because the balanced equation shows that 5 moles of $SO_2$ are required.

Option D (F) is correct because Fluorine is the most electronegative element and always exhibits a negative oxidation state.

Option C (+3) is correct because the oxidation number of nitrogen in the new compound X is calculated based on the electron loss and the initial oxidation state of nitrogen in hydrazine.

Option A ($+2$) is correct because the oxidation number of carbon in KCN is calculated based on the known oxidation states of K and N.

Option C (6) is correct because balancing the redox reaction shows that 6 moles of Fe2+ are required to react with 1 mole of dichromate.

Option C (${P}_4+{OH}^{-} \longrightarrow {PH}_3+{H}_2 {PO}_2^{-}$) is correct because it demonstrates a disproportionation reaction where the same element undergoes both oxidation and reduction.

Option D (All of these) is correct because the reaction involves complex formation, oxidation of KI, and reduction of I2.

Option D (Assertion is false, Reason is true) is correct because copper is a weaker reducing agent than hydrogen, and the standard reduction potential of Cu2+/Cu is positive.

Option A (+2 and +3) is correct because Fe3O4 is a mixed oxide containing FeO (oxidation state +2) and Fe2O3 (oxidation state +3).

Option A (Both the statements are correct) is correct because the reaction involves both oxidation and reduction, and sulfur in ${{\text{S}}_2}{\text{O}}_3^{2 - }$ does form colloidal sulfur.

Option C ($\mathrm{Tl}^{3+}$ only) is correct because $\mathrm{Tl}^{3+}$ ions are less stable than $\mathrm{Tl}^{+}$ ions and readily accept electrons, thus acting as an oxidizing agent.

The correct answer is $\mathrm{N}{\mathrm{H}_4}\mathrm{Cl} \to \mathrm{N}{\mathrm{H}_3} + \mathrm{HCl}$ because there is no change in oxidation number of any element during the reaction.

Option D (-1, -1, -1) is correct because hydrogen bonded to a more electropositive metal has a -1 oxidation state.

Option B (-1) is correct because the oxidation number of nitrogen in NH₂OH is calculated by setting the sum of oxidation numbers to zero.

The correct answer is D (A and B) because in a basic medium, hydrogen peroxide ($H_2O_2$) can act as both an oxidizing agent (reducing $I_2$ to $I^-$) and a reducing agent (oxidizing $Mn^{2+}$ to $Mn^{4+}$).

Option C (Both (1) and (2)) is correct because acidified $\mathrm{KMn}{\mathrm{O}_4}$ oxidizes ferrous oxalate to $\mathrm{F}{\mathrm{e}^{3 + }}$ and $\mathrm{C}{\mathrm{O}_2}$.

Option A ($+2$) is correct because the most stable oxidation state of copper is +2 due to its higher hydration energy which compensates for the second ionization enthalpy.

Option D ($\mathrm{Mn}^{+2}, \mathrm{I}_2$) is correct because it represents the products of the redox reaction where permanganate is reduced to manganese(II) and iodide is oxidized to iodine.

Option B (F) is correct because fluorine is the most electronegative element and only exhibits a -1 oxidation state in its compounds.

Option B (${\mathrm{N}_2}{\mathrm{O}_4}$) is correct because the oxidation number of nitrogen is +4, which is the highest among the given options.

Option A (1.4 g) is correct because 1 g of calcium produces 1.4 g of calcium oxide based on stoichiometry.

Option D (6) is correct because 6 moles of Mohr's salt ($Fe^{2+}$) are required to reduce 1 mole of dichromate ion ($Cr_2O_7^{2-}$).

Option A ($+ 3$) is incorrect. The correct oxidation number of N in NOCl is +1. The explanation provided in the original response is incorrect. The correct approach is to consider the oxidation states of O and Cl, which are -2 and -1 respectively. Therefore, the oxidation state of N is +3. However, the given correct answer is incorrect. The correct answer should be +1.

Option C (${\mathrm{C}_6}{\mathrm{H}_{12}}{\mathrm{O}_6}$) is correct because glucose is a reducing agent, meaning it donates electrons and gets oxidized, not reduced.

Option D is correct because electrolytes increase conductivity when dissolved in water by furnishing ions, making the assertion incorrect.

The correct answer is C (0 to + 5) because in the reaction $B{r_2} \to BrO_3^ -$, the oxidation state of bromine changes from 0 to +5.

Option C (2,1,1) is correct because it represents the correct coefficients for the balanced redox reaction in a basic medium.

Option C (${\mathrm{H}_2}\mathrm{S}$) is correct because in the reaction with $H_2S$, $SO_2$ acts as an oxidizing agent, getting reduced to elemental sulfur.

Option A ($x\,\mathrm{ = }\,F,Cl,Br,l\,\,\mathrm{and}\,\,y\, = \,F,Cl\,\,and\,\,Br$) is correct because $FeI_3$ does not exist due to $I^-$ being a strong reducing agent.

The correct answer is A ($Bi$) because Bismuth is a metal in group 15 and forms $BiH_3$, which has the weakest $Bi-H$ bond and thus the strongest reducing power.