{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

CHM152Chapter 17

Chemistry (MasteringChemistry Series)

Info icon This preview shows pages 1–5. Sign up to view the full content.

View Full Document Right Arrow Icon
1 1 Chapter 17 Electrochemistry Redox Reactions Electrochemistry is the study of batteries and interconversion of chemical and electrical energy. Based on redox (oxidation-reduction) reactions in which one element gains electrons and another loses electrons. These two processes MUST happen together. Have to assign oxidation numbers to determine (see Chapter 4). Oxidation Numbers Elements in their natural states are 0. Elements in binary ionic compounds are the same as their charges. H: usually +1 except with alkali metals it’s a H: usually +1, except with alkali metals it s a -1(LiH, NaH, etc.) O: usually -2, except in peroxides it’s a -1 (H 2 O 2 , K 2 O 2 ) The non-oxygen element in a polyatomic ion has to be determined from the other oxidation numbers.
Image of page 1

Info icon This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
2 2 Redox Reactions Oxidation: loss of electrons Reduction: gain of electrons LEO the lion goes GER or OIL RIG The substance oxidized is also called the reducing agent (it caused the other substance to be reduced). And vice versa. Cu(s) + AgNO 3 Æ Ag(s) + Cu(NO 3 ) 2 Cu(s) + AgNO 3 (aq) Redox Reactions CH 4 (g) + O 2 (g) Æ CO 2 (g) + H 2 O(g) Na(s) + HCl(aq) Æ NaCl(aq) + H 2 (g) For each reaction: What is oxidized, reduced? What is the oxidizing agent? Reducing agent? Combustion, decomposition, combustion, and single-replacement reactions are all redox.
Image of page 2