Chem 161-2010 Lecture 7 trunc

Chem 161-2010 Lecture 7 trunc - CHEMISTRY 161-2010 LECTURE...

Info iconThis preview shows pages 1–8. Sign up to view the full content.

View Full Document Right Arrow Icon
CHEMISTRY 161-2010 LECTURE 7 ANNOUNCEMENTS E-MAIL ATTENDANCE EXAMS/QUIZZES How did we do? Chem 161-2010 Lecture 7 1
Background image of page 1

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

View Full DocumentRight Arrow Icon
PLAN FOR TODAY CHAPTER 4 • OXIDATION-REDUCTION REACTIONS • TITRATIONS Chem 161-2010 Lecture 7 2
Background image of page 2
OXIDATION-REDUCTION REACTIONS We’ve studied two types of reactions Acid-base Precipitation Third type: Oxidation-reduction reactions ET: Define oxidation and reduction in terms of reaction with electronegative oxygen (or loss of electrons),. Fe + O 2 → Fe 2 O 3 ; define oxidation and reduction in terms of loss or gain of electrons. OILRIG: oxidation is loss of electrons; reduction is gain of electrons; OXLEA/GON: oxidation is loss of electrons at the anode or gain in oxidation number; reduction is gain of electrons at the cathode or reduction in oxidation number. Chem 161-2010 Lecture 7 3
Background image of page 3

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

View Full DocumentRight Arrow Icon
Chem 161-2010 Lecture 7 4
Background image of page 4
SOME NITROGEN OXIDATION STATES Ionic charge* = oxidation state = oxidation number (Oxidation state ranges from group no. to group no – 8) N oxidation state = 5 to (5-8=) -3, i.e., +5,+4,+3,+2,+1,0,-1,-2,-3 e.g., oxidation state of N in NO = +2 Chem 161-2010 Lecture 7 5 7+ 7+ 7+ NITROGEN ATOM 7protons + 7e - = 0 OXIDATION STATE: 0 NITROGEN CATION OXIDATION STATE: +7-2=+5 CAN ONLY BE REDUCED CAN EASILY GET PARTNER TO BE OXIZED (OXIDIZING AGENT ONLY) NITROGEN ANION OXIDATION STATE: +7-10=-3 CAN ONLY BE OXIDIZED (REDUCING AGENT ONLY) electron (electron has -1 charge) * If we think of the atom as being an ion remove 1,2,3,4 or 5 electrons from valence shell add 1,2 or 3 electrons to valence shell
Background image of page 5

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

View Full DocumentRight Arrow Icon
Nitrogen Oxidation Numbers (group number to group number – 8) NO 3 - +5 (maximum oxidation no.) (cannot be oxidized any further; can easily be reduced; good oxid agent) N 2 O 4 +4 NO 2 - +3 NO +2 N 2 O +1 N 2 0 NH 2 OH -1 N 2 H 4 -2 NH 3 -3 (minimum oxidation no.; red. agent) (cannot be reduced any further; can easily be oxidized; good reducing agent) Chem 161-2010 Lecture 7 6
Background image of page 6
OXIDATION-REDUCTION REACTIONS ET: “Oxidation number is sometimes described as “the charge an atom would have if it were an ion”. Oxidation Number Rules in order of priority:
Background image of page 7

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

View Full DocumentRight Arrow Icon
Image of page 8
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 15

Chem 161-2010 Lecture 7 trunc - CHEMISTRY 161-2010 LECTURE...

This preview shows document pages 1 - 8. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online