A common car battery consists of six identical cells each of which carries out the reaction: Pb + PbO₂ + 2HSO₄^- + 2H⁺ $\to$ 2PbSO₄ + 2H₂O
Suppose that in starting a car on a cold morning a current of 125 amperes is drawn for 18.4 seconds from a cell of the type described above.How many grams of Pb would be consumed? (The atomic weight of Pb is 207.19. )

Question

A common car battery consists of six identical cells each of which carries out the reaction: Pb + PbO₂ + 2HSO₄^- + 2H⁺

\to

2PbSO₄ + 2H₂O
Suppose that in starting a car on a cold morning a current of 125 amperes is drawn for 18.4 seconds from a cell of the type described above.How many grams of Pb would be consumed? (The atomic weight of Pb is 207.19. )

Quizplus · Accepted Answer

First, we need to find the amount of electrical charge that passed through the cell.

Current (I) = 125 A 
Time (t) = 18.4 s

Charge (Q) = I x t = 125 A x 18.4 s = 2300 C

Next, we can use the balanced chemical equation and the Faraday's law of electrolysis to find the amount of Pb consumed in the reaction:

2Pb + 2H+ → 2Pb2+ + H2 ↑

1 mol of Pb2+ (or Pb) ions require 2F of electrical charge to be reduced.

1F = 96485 C/mol e-

2F = 2 x 96485 = 192970 C/mol

Now we can find the moles of Pb consumed:

Moles of Pb consumed = (2300 C) / (192970 C/mol) = 0.01192 mol

Finally, we can convert the moles of Pb to grams using the molar mass of Pb:

Grams of Pb consumed = 0.01192 mol x 207.19 g/mol = 2.47 g

Therefore, the answer is B.

A Common Car Battery Consists of Six Identical Cells Each →\to→

A Common Car Battery Consists of Six Identical Cells Each $\to$