Ch21_1 - 1 ELECTROCHEMISTRY ELECTROCHEMISTRY Chapter 21...

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: 1 ELECTROCHEMISTRY ELECTROCHEMISTRY Chapter 21 Chapter 21 TRANSFER REACTIONS TRANSFER REACTIONS 2 Atom/Group transfer HCl + H 2O ---> HCl ---> ClCl + 3 Electron Transfer Reactions Electron Transfer Reactions • Electron transfer reactions are oxidationElectron oxidation- H3O+ reduction or redox reactions. redox • Redox reactions can result in the Electron transfer generation of an electric current or be Cu(s) + 2 Ag+(aq ) ---> Cu2+(aq) + 2 Ag(s) caused by imposing an electric current. • Therefore, this field of chemistry is often Electric automobile called ELECTROCHEMISTRY. called ELECTROCHEMISTRY. 4 5 6 Review of Terminology Review of Terminology for Redox Reactions for Redox Reactions OXIDATION-REDUCTION REACTIONS OXIDATION-REDUCTION OXIDATION-REDUCTION REACTIONS REACTIONS •• OXIDATION —loss of electron(s) by a OXIDATION—loss of electron(s) by a species; increase in oxidation number. species; increase in oxidation number. •• REDUCTION—gain of electron(s); REDUCTION—gain of electron(s); decrease in oxidation number. decrease in oxidation number. Direct Redox Reaction Oxidizing and reducing agents in direct contact. Cu(s) + 2 Ag+(aq ) ---> Cu2+(aq) + 2 Ag(s) Indirect Redox Reaction •• OXIDIZING AGENT —electron acceptor; OXIDIZING AGENT—electron acceptor; species is reduced. species is reduced. •• REDUCING AGENT—electron donor; REDUCING AGENT—electron donor; species is oxidized. species is oxidized. Page 1 A battery functions by transferring electrons through an external wire from the reducing agent to the oxidizing agent. Why Study Electrochemistry? Why Study Electrochemistry? • Batteries • Corrosion • Industrial production of chemicals such as such Cl2, NaOH, F2 and Al • Biological redox reactions 7 8 Electrochemical Cells Electrochemical Cells • An apparatus that allows a redox reaction to occur by transferring electrons through an external connector. • Product favored reaction ---> voltaic or galvanic cell ----> electric current • Reactant favored reaction ---> electrolytic cell ---> electric current used to cause chemical change. The heme group Page 2 Batteries are voltaic cells ...
View Full Document

Ask a homework question - tutors are online