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Hello, my name is margaret, and today i'm going to be helping you with zoomdahl, chapter 18, electrochemistry, problem number 13.
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And the problem says, consider the following galvanic cell, what happens to the cell potential as the concentration of zinc 2 plus is increased, as a concentration of silver, plus is increased, what happens to e not in these cases.
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So let's take a look.
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So if we look at this cell, which i'll sketch out really quickly.
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So we have the little filter in the middle that allows for ion exchange.
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And we have a one molar zinc two plus solution over here.
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And we have a one molar silver solution over here.
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We have a zinc electrode and a silver electrode.
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They are connected by a wire.
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Okay.
01:22
And so the first thing i would do in this situation to evaluate is i would always look up my standard reduction potentials, which is table.
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18 .1.
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And then that's page 709 in the textbook.
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And that is page 887 for the pdf, at least the one that i have.
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So really quickly, if you want to go look those up, you can.
02:00
So zinc 2 plus plus two electrons goes to sync solid.
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That potential is negative 0 .76.
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And silver plus an electron goes to silver as a solid.
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And that potential is 0 .80.
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These are both in volts.
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So, really quickly looking at the...
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These don't have any middleman mechanisms.
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And so if we wanted to just pound out the overall cell, equation really quickly, zinc is a solid plus 2, ag.
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So how did i figure that out so? a, g as a solid plus zinc, two plus.
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So how did i figure that out so quickly? so what we want to remember is that our cell potentials are a measure of spontaneity.
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Okay.
04:03
So positive cell potentials mean that they are spontaneous reactions.
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And negative cell potentials mean that they are non -spontaneous.
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Okay.
04:27
And so what this tells me is that because our e -not or our cell potential for the reduction of silver is positive means that it is favorable and spontaneous, whereas the reduction of zinc is negative, this means, so spontaneous...
