1 / 22

Redox!

Redox!. My favorite reaction. 2Na (s) + Cl 2(g) ->2NaCl (s) electron is transferred This is called oxidation-reduction or redox. Redox. Involves most rxns for energy production photosynthesis, combustion, breakdown of sugars, fats, proteins. Oxidation States.

preston-blanchard
Download Presentation

Redox!

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Redox!

  2. My favorite reaction... • 2Na(s) + Cl2(g)->2NaCl(s) • electron is transferred • This is called oxidation-reduction or redox

  3. Redox • Involves most rxns for energy production • photosynthesis, combustion, breakdown of sugars, fats, proteins

  4. Oxidation States • A way to keep track of electrons in redox rxns • Oxidation states of covalent cmpds- arbitrarily assigned to certain atoms

  5. Rules- Oxidation States • Oxidation state of an atom in an element is zero.

  6. Element Examples... • Na(s), O2(g), O3(g), Fe(s), Hg(l) all have an oxidation state of 0

  7. Monatomic Ions • Oxidation state of monatomic ion is the same as its charge

  8. Monatomic Ion Ex • Oxidation state of: • Na+ = +1 • Cl- = -1 • Ca2+ = +2

  9. Fluorine • In its compounds, fluorine always has an oxidation state of -1.

  10. Oxygen • Assigned oxidation state of -2 in its covalent compounds. • CO, CO2, SO2, SO3

  11. Hydrogen Rules • In covalent compounds with nonmetals, H is assigned an oxidation state of +1.

  12. Hydrogen examples • HCl, NH3, H2O, CH4 • all have hydrogen at +1 oxidation state

  13. Sum of the states • Sum of the oxidation states must be 0 for neutral compounds or the charge of the ion for an ion

  14. Examples • Sum of states in CO32- • -2 • Sum of states in NH4+ • +1

  15. Let’s Try It! • CO2 • SF6 • NO3- • K2CrO4

  16. Redox Rxns • Some rxns are characterized by literal e- transfer • 2Na(s) + Cl2(s)->2NaCl(s)

  17. Less obvious redox • CH4(g) + 2O2(g) -->CO2(g) +H2O(g) • Assign oxidation states

  18. A closer look • Oxidation is an increase in oxidation state (a loss of electrons)

  19. A closer look • Reduction is a decrease in oxidation state (a gain of electrons)

  20. In the reaction... • 2Na(s) + Cl2(s)->2NaCl(s) • sodium is oxidized • chlorine is reduced

  21. However... • Chlorine is the oxidizing agent (e- acceptor) • sodium is the reducing agent (e- donor)

  22. In the other rxn... • C is oxidized (lost e-) • O is reduced (gained e- • CH4 is reducing agent • O2 is oxidizing agent

More Related