CO2(g)+2H+(aq)+2e−→HCOOH(l) Eo=−0.20V

Which of the following substances oxidizes HCOOH(l)?

Select one:

Pb2+(aq)

Pb(s)

Zn2+(aq)

Zn(s)

 

the energy from an alkaline battery is generated by the following equation.

Zn(s)+2MnO2(s)→ZnO(s)+Mn2O3(s)

During the operation of the alkaline battery, which of the following observations can be made?

Select one:

The amount of MnO2(s) increases as Zn(s) is reduced.

The amount of Zn(s) increases as MnO2(s) is reduced.

The amount of MnO2(s) decreases as Zn(s) is oxidized.

The amount of Zn(s) decreases as MnO2(s) is oxidized.

6 years ago

Answered By An B

The first question's answer is Zn2+(s). To oxidize HCOOH, the substance must be able to be reduced. This leaves us with two options, Zn2+ and Pb2+. Pb is a really weak metal, like Cu or Ag so Pb2+ can be eliminated.

The second question's answer is "The amount of MnO2 decreases as Zn is oxidized". If the reaction shifts right, Zn will be oxidized and MnO2 will be consumed, therefore, decreases in its amount.

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