Suppose the redox reaction in a certain zinc-carbon battery is Zn + 2 MnO₂ + 2 NH₄Cl $\to$Mn₂O₃ + Zn(NH₃)₂Cl₂ + H₂O.The battery is rated at 0.75 W . hr at 1.5 V.How many grams of zinc must be oxidized to deliver this much electrical energy?

Question

Quizplus · Accepted Answer

Firstly, we need to calculate the total energy produced by the battery:
0.75 W * 1.5 V * 1 hr = 1.125 Wh = 1.125 x 10^3 Wh

Next, we need to calculate the amount of charge transferred in the reaction:
Number of moles of electrons transferred = (2 moles of electrons per mole of Zn) * (mass of Zn / molar mass of Zn) = 2 * m / 65.38 
where m is the mass of Zn in grams.

The charge transferred can be calculated using Faraday's constant:
q = (number of moles of electrons transferred) * (Faraday's constant)
q = 2F * m / 65.38

Finally, we can calculate the mass of Zn required to produce 1.125 x 10^3 Wh of energy:
1.125 x 10^3 Wh = (q * 1 V) / 3600 s
m = 65.38 * (1.125 x 10^3 Wh) * 3600 / (2F * 1 V)

Plugging in the values, we get:
m = 0.61 g Zn

Therefore, the answer is (C) 0.61 g Zn.

Suppose the Redox Reaction in a Certain Zinc-Carbon Battery Is →\to→

Suppose the Redox Reaction in a Certain Zinc-Carbon Battery Is $\to$