Electrochemistry

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Active nonmetals:

Gain electrons easily

Are easily reduced

Are strong oxidizing agents

Slide 12

Electrochemical Terminology

Half-cell: a metal electrode in contact with a solution of its own ions

Electrode: A conductor used to establish contact with a nonmetallic part of a circuit, such as an electrolyte

Anode: The electrode where oxidation takes place

Cathode: The electrode where reduction takes place

Slide 13

Voltaic Cells

Voltaic cells: Electrochemical cells in which a spontaneous redox reaction can be harnessed to produce an electric current.

Anode:

negative

Cathode:

positive

Slide 14

Zinc – Copper Battery

Slide 15

Zinc-Carbon Dry Cell Battery

Slide 16

Mercury Dry Cell Battery

Slide 17

Lead Storage Automotive Battery

Slide 18

Electrolytic Cells

Electrolytic cells: Electrochemical cell in which an electric current is used to drive a non-spontaneous process

Cathode:

negative

Anode:

positive

Slide 19

Electrolysis of H2O

2H2O  2H2 + O2

Electrolyte is usually dilute sulfuric acid

Slide 20

Electroplating of Silver

Cathode is the object to be plated

Anode is a piece of the plating metal

Solution contains ions of the plating metal

Slide 21

Standard Reduction Potentials

Slide 22

Measuring Electrode Potential

1. H2 Electrode is assigned a potential of zero volts

2. Second electrode is placed in a solution of its own ions

3. Reduction potential of second electrode is measured.