March 27, 2009 - zn – E Fe =-0.76 – 0.77 =-1.53V • If...

Info icon This preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
March 27, 2009
Image of page 1

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

View Full Document Right Arrow Icon
A + B + → A + + B Or A | A + # B + |B For both B product metal A reactant metal E reaction = E B o - E A o
Image of page 2
Reference electrode 2H + + 2e H 2 E = 0 Pt|H 2 (g)|H + To measure reduction potentials, place on right side
Image of page 3

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

View Full Document Right Arrow Icon
Standard Potential for Zn 2+ + 2e → Zn Pt|H 2 |H + # Zn 2+ |Zn E = E Zn - E H2 = -0.76V on Zn 2+ electrode =- 0.76V – 0 Electrons right to left , cations left to right Zn metal disappears, H 2 is formed
Image of page 4
Pt|H 2 |H + # Cu 2+ |Cu Cu electrode 0.34 E = E Cu – E H2 = +.34 – 0 = 0.34V Reaction left to right so H 2 + Cu 2+ 2 H + + Cu Spontaneous • H 2 oxidized Cu 2+ reduced
Image of page 5

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

View Full Document Right Arrow Icon
Zn + Cu 2+ Zn 2+ + Cu E = E Cu – E Zn = 0.34 – (-0.76) + 1.1V Reaction spontaneous as written Further down table more likely to be reduced oxidizing agent
Image of page 6
Non metals See from table “electrode” metal ion with higher charge it will receive electron(s) Fe 3+ + 1e → Fe 2+ 0.77 Fe 2+ (lower charge) is like metal Fe 2+
Image of page 7

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

View Full Document Right Arrow Icon
Fe 3+ + e → Fe 2+ + e E = 0.77 Zn 2+ + 2e Zn E = -0.76 Fe 2+ + Zn 2+ Fe 3+ + Zn (unbalanced) E = E
Image of page 8
Image of page 9

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

View Full Document Right Arrow Icon
Image of page 10
Image of page 11

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

View Full Document Right Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: zn – E Fe = -0.76 – (+0.77) = -1.53V • If know Zn position – just take “Fe” from table and insert • Electrode of second kind • Ag + ion can be very poisonous • For biological systems • Cl 2 also poisonous but Cl-is not • Ag|AgCl electrode really Cl-electrode • +V • electrode 1 Ag + Cl-|Ag • AgCl insoluble on surface • Ag + moves to Ag electrode, receives e and becomes Ag leaving a Cl-behind • Cl-moves off surface into solution • Ag never leaves the electrode • Other electrode • Ag | Ag + Cl-• e separates from Ag metal to move in wire and creates Ag + ion near surface • Cl- ion moves to electrode AgCl precipitate on surface • Net effect for a spontaneous reaction • Electrodes move left to right in wire • Cl- ions move right to left in solution • Left to right rule is reversed for negative ions • Only Cl-enters or leaves solution...
View Full 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