Question

1) If, in using a lead-acid battery to start a car, 1.00 g of Pb is consumed on the anode, how long will it take to recharge the battery, using a current of 0.500 amps, and turn the PbSO4 that was produced back into Pb?

2) The Energizer bunny in the television commercial "keeps going and going." What property of the battery (voltaic cell) is being featured in this commercial?

Answer 1

Part 1)

Pb²⁺ +2e^-      Pb(s)

Thus, one mole of Pb require 2 moles of electrons

Moles of electrons required to deposit 1 g of Pb can be calculated as,

Moles of e^- = 1 g x (1 mole Pb/ 207.2 g/mol) x (2 mole e^-/1 mole Pb ) = 9.65 x 10^-3 mole e^-

Time required = (9.65 x 10^-3 mole e^-) x (96500)/ 0.5 Ampere = 1860 seconds

                                                                                                            = (1860 s)/60 = 31 min

Part 2)

The property of the battery featured in the commercial is the higher the energy density or the larger quantities of reactants used in the battery