Question

which statement among a - c is false regarding the redox reactions shown? o it requires energy to reduce sulfate (so42 - ). o hydrogen sulfide (h2s) would be considered a strong electron donor. o nitrite (no2 - ) is a stronger terminal electron acceptor than sulfate (so42 - ). electron acceptor electron donor e° (mv)a δg° (kj) no2 - + 8h+ + 6e - → nh4+ + 2h2o +440 - 255 so42 - + 10h+ + 8e - → h2s + 4h2o - 220 + 170

Explanation:

Step1: Analyze electron - acceptor strength

The more positive the standard reduction potential ($E^0$), the stronger the electron - acceptor. The $E^0$ for $NO_2^-$ reduction is more positive ($ + 440$ mV) compared to $SO_4^{2 - }$ reduction ($- 220$ mV), so $NO_2^-$ is a stronger terminal electron - acceptor than $SO_4^{2 - }$.

Step2: Analyze electron - donor strength

Hydrogen sulfide ($H_2S$) has a relatively high tendency to donate electrons. A negative $E^0$ value for the reaction involving $H_2S$ indicates it is an electron - donor, and its properties make it a strong electron - donor.

Step3: Analyze reduction of sulfate

Reducing sulfate ($SO_4^{2 - }$) is an energy - requiring process as indicated by the positive $\Delta G^0$ value ($+170$ kJ).

Answer:

None of the above statements are false.