{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Chapt 20_10_ed_stu_07

Chapt 20_10_ed_stu_07 - Redox Equations involve the...

Info icon This preview shows pages 1–11. Sign up to view the full content.

View Full Document Right Arrow Icon
Redox Equations involve the transfer of one or more electrons OXIDATION - loss of electrons - increase in oxidation number REDUCTION - gain of electrons - decrease in oxidation number
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
OXIDIZING AGENT - causes something to be oxidized - gets reduced in the process. - is an electron acceptor. REDUCING AGENT - causes something to be reduce - gets oxidized in the process. - is an electron donor.
Image of page 2
Rules For Balancing Redox Equations by the Half-Reaction Method 1) Break the reaction down into two half-reactions. 2) Balance all atoms except for H’s and O’s. (This may involve adding the expected redox product in some cases.) 3) Balance each half reaction by adding H 1+ 's and H 2 O‘s as needed to balance the atoms in the half reaction. If the reaction is in ACID skip to step 5. 4) For reactions in BASE, convert all H 1+ ’s ions to H 2 O by adding an equal number of OH 1- ions to that of the H 1+ ions to both side of the equation. The OH 1- ’s ions will react with the H 1+ ’s ions converting them H 2 O.
Image of page 3

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

View Full Document Right Arrow Icon
5) Balance the charges in the half-reactions by adding electrons. 6) Multiply the half-reaction by the least common multiple such that THE NUMBER OF ELECTRONS LOST IS EQUAL TO THE NUMBER OF ELECTRONS GAINED. 7) Add the two half-reactions together, canceling out any H 1+ 's, OH 1- 's and H 2 O's that appear on both sides of the equation.
Image of page 4
Fe 2+ + Cr 2 O 7 2- R Fe 3+ + Cr 3+ (acid) Fe 2+ + Cr 2 O 7 2- R Fe 3+ + Cr 3+ (acid) Fe 2+ R Fe 3+ + e 1- Cr 2 O 7 2- R Cr 3+ Cr 2 O 7 2- R 2 Cr 3+ Cr 2 O 7 2- R 2 Cr 3+ + 7 H 2 O 14 H 1+ + Cr 2 O 7 2- R 2 Cr 3+ + 7 H 2 O 14 H 1+ + Cr 2 O 7 2- + 6 e 1- R 2 Cr 3+ + 7 H 2 O (+12) (+6) 6 (Fe 2+ R Fe 3+ + e 1- ) 14H 1+ + 6 Fe 2+ + Cr 2 O 7 2- R 6 Fe 3+ + 2 Cr 3+ + 7 H 2 O Check: both the number of each atom on each side must be balanced and the total charges on each side must be equal.
Image of page 5

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

View Full Document Right Arrow Icon
Mn 2+ + BiO 3 1- R MnO 4 1- + Bi 3+ (acid) Mn 2+ + BiO 3 1- R MnO 4 1 - + Bi 3+ (acid) Mn 2+ R MnO 4 1- Mn 2+ + 4 H 2 O R MnO 4 1- Mn 2+ + 4 H 2 O R MnO 4 1- + 8 H 1+ Mn 2+ + 4 H 2 O R MnO 4 1- + 8 H 1+ + 5 e 1- BiO 3 1- R Bi 3+ BiO 3 1- R Bi 3+ + 3 H 2 O BiO 3 1- + 6 H 1+ R Bi 3+ + 3 H 2 O BiO 3 1- + 6 H 1+ + 2 e 1- R Bi 3+ + 3 H 2 O
Image of page 6
Mn 2+ + 4 H 2 O R MnO 4 1- + 8 H 1+ + 5 e 1 - BiO 3 1- + 6 H 1+ + 2 e 1- R Bi 3+ + 3 H 2 O 2( Mn 2+ + 4 H 2 O R MnO 4 1- + 8 H 1+ + 5 e 1- ) 5 ( BiO 3 1- + 6 H 1+ + 2 e 1- R Bi 3+ + 3 H 2 O ) Now have 10 e 1- on each side 8 H 2 O + 2 Mn 2+ + 30 H 1+ + 5 BiO 3 1- R 5 Bi 3+ + 2 MnO 4 1- + 16 H 1+ + 15 H 2 O 8 H 2 O + 2 Mn 2+ + 30 H 1+ 5 BiO 3 1- R 5 Bi 3+ +2 MnO 4 1- + 16 H 1+ + 15 H 2 O 2 Mn 2+ 14 H 1+ + 5 BiO 3 1- R 5 Bi 3+ + 2 MnO 4 1- + 7 H 2 O
Image of page 7

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

View Full Document Right Arrow Icon
Reactions in base AsO 3 3- + I 2 R AsO 4 3- + I 1- (base) AsO 3 3- + I 2 R AsO 4 3- + I 1- (base) I 2 R I 1- I 2 R 2 I 1- I 2 + 2 e 1- R 2 I 1- AsO 3 3- R AsO 4 3- H 2 O + AsO 3 3- R AsO 4 3- H 2 O + AsO 3 3- R AsO 4 3- + 2 H 1+ add 2 OH 1- ’s to each side of the equation 2 OH 1- + H 2 O + AsO 3 3- R AsO 4 3- + 2 H 1+ + 2 OH 1- 2 H 2 O 2 OH 1- + AsO 3 3- R AsO 4 3- + H 2 O
Image of page 8
2 OH 1- + AsO 3 3- R AsO 4 3- + H 2 O 2 OH 1- + AsO 3 3- R AsO 4 3- + H 2 O + 2e + 1- I 2 + 2 e 1- R 2 I 1- 2 OH 1- + AsO 3 3- + I 2 R 2 I 1- + AsO 4 3- + H 2 O
Image of page 9

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

View Full Document Right Arrow Icon
CrO 4 2- + HSnO 2 1- R HSnO 3 1- + CrO 2 1- (base) CrO 4 2- + HSnO 2 1- R HSnO 3 1- + CrO 2 1- (base) HSnO 2 1- R HSnO 3 1- HSnO 2 1- + H 2 O R HSnO 3 1- HSnO 2 1- + H 2 O R HSnO 3 1- + 2 H 1+ 2 OH 1- + HSnO 2 1- + H 2 O R HSnO 3 1- + 2 H 1+ + 2 OH 1- 2 OH 1- + HSnO 2 1- + H 2
Image of page 10
Image of page 11
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern