Question

Which species in the pair is the stronger oxidizing agent? (a) Cr or Cd (b) \(\mathrm{I}^{-}\) or \(\mathrm{Br}^{-}\) (c) \(\mathrm{OH}^{-}\) or \(\mathrm{NO}_{2}^{-}\) (basic solution) (d) NO in acidic solution or NO in basic solution

Short answer

Question: Identify the stronger oxidizing agent in each pair: (a) Cr or Cd, (b) I⁻ or Br⁻, (c) OH⁻ or NO2⁻ (in a basic solution), (d) NO in acidic or basic solution. Answer: Based on the comparison of standard reduction potentials, the stronger oxidizing agents for each pair are: (a) Cd, (b) Br⁻, (c) NO2⁻ (in basic solution), and (d) NO (in basic solution).

Step-by-step solution

Obtain the Standard Reduction Potentials

Look up the standard reduction potentials for each species in each pair from a table of electrode potentials. The values are as follows: (a) Cr: Eº = -0.74 V; Cd: Eº = -0.40 V (b) I⁻: Eº = +0.54 V; Br⁻: Eº = +1.09 V (c) OH⁻: Eº = +0.40 V; NO2⁻: Eº = +0.836 V (assuming basic solution) (d) NO (in acidic solution): Eº = +0.96 V; NO (in basic solution): Eº = +1.231 V

Compare Reduction Potentials for Each Pair

Compare the reduction potentials within each pair, and determine which species has the higher value. The species with the higher reduction potential is the stronger oxidizing agent. (a) Cr (-0.74 V) and Cd (-0.40 V): Cd has the higher reduction potential. Therefore, Cd is the stronger oxidizing agent. (b) I⁻ (+0.54 V) and Br⁻ (+1.09 V): Br⁻ has the higher reduction potential. Therefore, Br⁻ is the stronger oxidizing agent. (c) OH⁻(+0.40 V) and NO2⁻ (+0.836 V): NO2⁻ has the higher reduction potential. Therefore, NO2⁻ is the stronger oxidizing agent in basic solution. (d) NO (in acidic solution: +0.96 V) and NO (in basic solution: +1.231 V): NO in basic solution has the higher reduction potential. Therefore, NO is the stronger oxidizing agent in basic solution compared to acidic solution.

Final Answer

Based on the comparison of standard reduction potentials, the stronger oxidizing agents for each pair are: (a) Cd, (b) Br⁻, (c) NO2⁻ (in basic solution), and (d) NO (in basic solution).