Che 103 chapter3

Reduced since copper goes from zero to 2 it is

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: n must have an oxidation number of +3! WHY? Recognizing a Redox Reaction In a RedOx reaction, the species oxidized and the RedOx species reduced are identified by the changes in oxidation numbers : oxidation Oxidation numbers: +1 0 2Ag+ (aq) + Cu(s) → 2Ag(s) + Cu2+ (aq) 0 +2 Oxidation numbers: Since silver goes from +1 to zero, it is reduced. reduced Since copper goes from zero to +2, it is oxidized. oxidized The reaction is balanced for both mass and charge. Practice: Practice: Identify the species that is Oxidized and Oxidized Reduced by assigning oxidation numbers in the Reduced following reaction. 2 3CH4 (g) + Cr2O7 − (aq) + 8H+ (aq) → 3+ 3CH3OH(l) + 2Cr (aq) + 4H2O(l) Answer: Practice: Practice: Identify the species that is Oxidized and Oxidized Reduced by assigning oxidation numbers in the Reduced following reaction. 2 3CH4 (g) + Cr2O7 − (aq) + 8H+ (aq) → 3+ 3CH3OH(l) + 2Cr (aq) + 4H2O(l) Answer: •The carbon in methane (CH4) is oxidized (−4 to −2) •Chromium in dichromate is reduced (+6 to +3) Redox Reactions Redox Oxidation-Reduction Reactions • Iron gains 3 electrons (+3 to 0) oxidation number change. It is Reduced. • Carbon loses 2 electrons (+2 to +4) it is Oxidized. Oxidized Redox Reactions REDOX = reduction & oxidation REDOX Corrosion of aluminum 2 Al(s) + 3 Cu2+(aq) → 2 Al3+(aq) + 3 Cu(s) Redox Reactions Cu(s) + 2 Ag+(aq) → Cu2+(aq) + 2 Ag(s) In all reactions if a species is oxidized then another species must also been reduced Redox Reactions Redox Cu(s) + 2 Ag+(aq) →Cu2+(aq) + 2 Ag(s) Electron Transfer in a Redox Reaction Reaction e− e− 2Ag+(aq) + Cu(s) → Cu2+(aq) + 2Ag(s) • • • • Two electrons leave copper. The silver ions accept them. The copper metal is oxidized to copper (II) ion. The silver ion is reduced to solid silver metal. Redox Reactions in Our World Batteries Corrosion Fuels Manufacturing metals...
View Full Document

This note was uploaded on 04/09/2014 for the course CHE 103 taught by Professor Moran during the Spring '07 term at West Chester.

Ask a homework question - tutors are online