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![Page 1: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/1.jpg)
A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.
A Chemical Cell
The Copper-Zinc Cell
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We’ll construct this cell. We start with two empty containers…
containers
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We place a strip of copper metal in one of them. We call this a copper electrode.
Cucopper
electrode
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A metal is composed of neutral atoms. We’ll show (click) a few neutral copper atoms on this electrode.
CuCu
Cu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
copper electrode
![Page 5: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/5.jpg)
In the other container, we’ll place a piece of zinc metal, which we call the zinc electrode.
Cu ZnCu
Cu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
zinc electrode
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We’ll show a few neutral zinc atoms (click) on this electrode.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
zinc electrode
![Page 7: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/7.jpg)
We obtain an ammeter. A ammeter measures the rate of flow of electrons, or current.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
ammeter
A
![Page 8: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/8.jpg)
We’ll attach the ammeter to each electrode using conducting wires.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
+–
+–A
wires
![Page 9: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/9.jpg)
wires are composed of neutral atoms, which have the same number of protons as electrons.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
Wires are composed of neutral
atoms
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 10: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/10.jpg)
Because protons are positive, we’ll represent protons in the wires by positive charges
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
protons
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 11: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/11.jpg)
And electrons are negative, so we’ll represent electrons by negative charges.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
electrons
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 12: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/12.jpg)
Protons in all materials are in fixed positions in the nuclei of atoms, so they don’t move in the wires.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
protons are infixed positions
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 13: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/13.jpg)
But in metals, electrons can move easily
ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
Cu++++++++++++++++++
++
–––
––
–
+ +–––––––––––––– – –A
electrons
![Page 14: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/14.jpg)
In the container with the copper electrode, we add some copper(II) nitrate solution
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
Cu(NO3)2
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 15: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/15.jpg)
Copper(II) nitrate consists of (click) copper 2 plus ions and (click) nitrate ions. These ions are free to move around in the solution.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
Cu(NO3)2
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 16: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/16.jpg)
The three copper 2+ ions we’ve represented here, have total charge of positive 6.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
+6
![Page 17: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/17.jpg)
And the six nitrate ions we’ve represented have a total charge of negative 6, so at this point, charges are balanced in this solution.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
–6
![Page 18: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/18.jpg)
In the beaker with the zinc electrode, we add zinc nitrate solution.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
Cu(NO3)2 Zn(NO3)2
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 19: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/19.jpg)
Zinc nitrate solutions consists of (click) zinc 2 plus ions and (click) nitrate ions
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
Cu(NO3)2 Zn(NO3)2
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 20: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/20.jpg)
The zinc 2+ ion we’ve represented here has a charge of positive 2.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
Cu(NO3)2 Zn(NO3)2
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
+2
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And the two nitrate ions we’ve represented have total charge of negative 2. So at this point, charges are also balanced in this solution.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
Cu(NO3)2 Zn(NO3)2
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
–2
![Page 22: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/22.jpg)
Between the two containers we add (click) an inverted U tube with a solution of a salt like potassium nitrate, KNO3.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
Cu(NO3)2 Zn(NO3)2
KNO3
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 23: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/23.jpg)
We call this a salt bridge.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu 3NO
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
KNO3
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 24: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/24.jpg)
KNO3 solution consists of K plus and NO3 minus ions. Like all ions in solutions, these ions are free to move.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+KNO3
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 25: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/25.jpg)
Now we’ll focus on the zinc electrode and have a look at one of the zinc atoms.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
–
+–
+–A
![Page 26: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/26.jpg)
–
This zinc atom loses two electrons and changes into a zinc 2 plus ion, as shown by the equation Zn gives Zn2+ plus 2 electrons. This ion then (click) leaves the metal and is dissolved in the solution.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–A
–2Zn Z
n–
Zn Zn2+ + 2e–
![Page 27: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/27.jpg)
–
–
–
The electrons supplied by the zinc push the other electrons through the wire (click twice while watching)
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
–
AZn Zn2+ + 2e–
![Page 28: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/28.jpg)
–
–
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
AZn Zn2+ + 2e–
![Page 29: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/29.jpg)
–
Meanwhile, over at the copper electrode, a copper 2+ ion moves to the surface of the electrode.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
–––
AZn Zn2+ + 2e–
![Page 30: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/30.jpg)
–
The two extra electrons on the copper electrode (click), move onto the Copper 2+ ion
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
2Cu
––
Zn Zn2+ + 2e–
![Page 31: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/31.jpg)
–
The copper 2+ ion gains these electrons and changes into a neutral copper atom, as shown by the equation Cu2+ plus 2 electrons forms Cu.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
2Cu –Cu–
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
![Page 32: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/32.jpg)
–
This whole process keeps repeating itself, causing electrons to continuously move through the ammeter.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
Cu(NO3)2 Zn(NO3)2
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
![Page 33: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/33.jpg)
–
Now, we’ll focus on the ions in the container with the copper(II) nitrate solution
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
Cu(NO3)2
![Page 34: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/34.jpg)
–
In our example, one copper(II) ion was used up.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
Cu(NO3)2
used up
![Page 35: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/35.jpg)
–
The two copper ions that now remain, have a total charge of positive 4.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
+4
![Page 36: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/36.jpg)
–
And the six nitrate ions have total charge of negative 6.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
–6
![Page 37: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/37.jpg)
–
So there is an excess of negative charge in the solution in the container on the left.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
excess of negative charge
![Page 38: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/38.jpg)
–
Now, we’ll focus on the container on the right, with the zinc nitrate solution.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
excess of negative charge
Zn(NO3)2
![Page 39: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/39.jpg)
–
In our example, one zinc 2+ ion was produced…
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
excess of negative charge
Zn(NO3)2
produced
![Page 40: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/40.jpg)
–
The two zinc 2+ ions that are now present, have total charge of positive 4
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
excess of negative charge
+4
![Page 41: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/41.jpg)
–
And the two nitrate ions have a total charge of negative 2.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
excess of negative charge
–2
![Page 42: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/42.jpg)
–
So there is an excess of positive charge in the solution in the container on the right.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
excess of negative charge
excess of positive charge
![Page 43: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/43.jpg)
–
In order to balance charges, positive ions tend to move (click) toward the left through the salt bridge, away from the side with excess positive charge and toward the side with excess negative charge.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
2Zn 3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
K+
K+
K+
K+
3NO
3NO
3NO
3NO
3NO
3NO
K+
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
excess of negative charge
excess of positive charge
K+
![Page 44: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/44.jpg)
–
And negative ions tend to (click) move toward the container on the right, away from the side with excess negative charge and toward the side with excess positive charge.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
3NO
3NO
3NO
3NO
3NO
3NO
3NO
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
excess of negative charge
excess of positive charge
K+
K+
K+K
+
K+
K+
2Zn
![Page 45: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/45.jpg)
–
So the salt bridge is an important part of a chemical cell. It allows positive and negative ions to move through it so that the charges in the solutions remain balanced. Without a salt bridge, a chemical cell would not work.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
A
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
K+
K+
K+K
+
K+
K+
2Zn 3NO
3NO
3NO 3NO
3NO
3NO
3NO
Allows ions to
move so charges
are balance
d
![Page 46: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/46.jpg)
–
If we were to replace the ammeter with a voltmeter,
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
V
Cu
K+
K+
K+K
+
K+
K+
2Zn 3NO
3NO
3NO 3NO
3NO
3NO
3NO
![Page 47: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/47.jpg)
–
Under what are called standard conditions, this cell would initially have a voltage of 1.1 volts.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
V
Cu
K+
K+
K+K
+
K+
K+
2Zn 3NO
3NO
3NO 3NO
3NO
3NO
3NO
Voltage = 1.1 volts
![Page 48: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/48.jpg)
–
As this cell operates (click), zinc atoms will continue to dissolve to form zinc ions as they lose electrons…
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
V
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
K+
K+
K+K
+
K+
K+
2Zn 3NO
3NO
3NO 3NO
3NO
3NO
3NO
![Page 49: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/49.jpg)
–
And (click) copper 2+ ions will continue to gain electrons as they form copper atoms.
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
V
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
K+
K+
K+K
+
K+
K+
2Zn 3NO
3NO
3NO 3NO
3NO
3NO
3NO
![Page 50: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/50.jpg)
–
As zinc atoms on the zinc electrode dissolve,
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
V
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
K+
K+
K+K
+
K+
K+
2Zn 3NO
3NO
3NO 3NO
3NO
3NO
3NO
Zinc atoms are dissolved
![Page 51: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/51.jpg)
–
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
V
Cu
Cu2+ + 2e– Cu Zn Zn2+ + 2e–
K+
K+
K+K
+
K+
K+
2Zn 3NO
3NO
3NO 3NO
3NO
3NO
3NO
Zinc atoms are dissolved
And copper 2+ ions in the copper(II) nitrate solution are used up, the voltage supplied by this cell will gradually decrease,
Cu2+ ions are used
up
![Page 52: A simple chemical cell can be set up using copper and zinc electrodes. Here, we’ll show you how it works.](https://reader035.fdocuments.in/reader035/viewer/2022070418/5697bfc31a28abf838ca55d3/html5/thumbnails/52.jpg)
–
Cu ZnZn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
Zn
ZnZ
nZn
ZnZ
nZn
Zn
CuCu Cu
CuCu Cu
CuCu Cu
CuCu Cu
CuCu
Cu
3NO
3NO
2Cu
2Cu
3NO3NO
3NO
3NO
3NO
salt bridge
++++++++++++++++++
++ –
––––––––
––– –––––––
+–
+–
2Zn
––––
V
Cu
K+
K+
K+K
+
K+
K+
2Zn 3NO
3NO
3NO 3NO
3NO
3NO
3NO
Zinc atoms are dissolved
and will over time, drop to zero.
Cu2+ ions are used
up
Voltage = 0 volts