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This 15-slide PowerPoint lesson on Oxidation Numbers begins by reviewing redox reactions. It then outlines oxidation numbers before describing the rules used to assign oxidation numbers. The lesson package concludes by checking students’ understanding.

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In order, the lesson covers:

– Review

– Oxidation-Reduction Reactions

– Oxidation Number

– Rules for Assigning Oxidation Number

– Questions to Help You Assign Oxidation Number

– Assigning Oxidation Numbers

– Check Your Understanding

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Redox and Assigning Oxidation Numbers

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Redox and Assigning Oxidation Numbers

Oxidation-Reduction Reactions “Redox”

assigning oxidation numbers ppt

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assigning oxidation numbers ppt

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assigning oxidation numbers ppt

Redox Reactions. What is redox? Redox reactions involve a transfer of electrons. Oxidation – involves losing electrons (increase in oxidation number)

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assigning oxidation numbers ppt

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assigning oxidation numbers ppt

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assigning oxidation numbers

Assigning Oxidation Numbers

Nov 03, 2012

110 likes | 294 Views

Assigning Oxidation Numbers. What are the step-by-step procedures to writing a formula?. Did you notice anything during the do-now activity?. Were there any coincidences? Let’s talk about it. Rules for assigning Oxidation numbers.

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Assigning Oxidation Numbers What are the step-by-step procedures to writing a formula?

Did you notice anything during the do-now activity? • Were there any coincidences? Let’s talk about it.

Rules for assigning Oxidation numbers • The oxidation number of free elements is always zero (Example: Cl0, Mg0, H20) • This includes diatomic elements (H2 N2 F2 O2 I2 Cl2 Br2) and certain molecular substances (P4 and S8) • A good way to remember these elements is with the phrase "BrINClHOF"

Continued 2. The oxidation number of a monatomic ion is equal to its charge Example: Na+1 means that its oxidation number is +1 Cl-1 means that its oxidation number is -1

Continued 3. The algebraic sum of the oxidation numbers of all the atoms in the formula of a compound is zero Example: NaCl Na+1 Cl-1 1 + (-1)= 0 ***NOTE: for the most part, the first element will have a POSITIVE CHARGE and the second element will have a NEGATIVE CHARGE***

Continued 4. The oxidation number of hydrogen is +1 5. The oxidation number of oxygen is -2

Continued 6. The algebraic sum of the atoms in the formula of polyatomic ion (found on table E) is equal to its charge: Example: CN-1 C+2 N-3 +2 + (-3) = -1

Continued 7. In combinations of non-metals, the oxidation number of the less electronegative element is positive and that of the more electronegative element is negative. Example: HF: (H electronegativity= 2.2) (F electronegativity= 4.0) Because of this, hydrogen’s charge will be positive and fluorine’s charge will be negative H+1F-1

Let’s try some together: • Cu • F2 • H2O • MgI2 • CuSO4

Exceptions for assigning oxidation numbers • NH4+1 : when assigning the oxidation number for these, the only way this works is if nitrogen has a negative charge. • Example: N-3 H4+1 • (-3) + 1(4)= +1 • O2-2: to assign peroxide each element’s oxidation number, the only way it can add up to -2 is if each oxidation number is -1 • Example: O-1O-1 • (-1) + (-1) = -2

Continued 3. OH-1: The only way these oxidation numbers will work is if the first element (oxygen) in this compound has a negative charge: Example: O-2 H+1 -2 + 1= -1 4. S2O3-2: For this compound, the only way that it works is if Sulfur has a positive 2 charge: Example: S2+2 O3-2 2(2) + 3(-2) 4+(-6) =-2

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Rules for Assigning Oxidation Numbers (OpenChem)

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What Are the Rules for Assigning Oxidation Numbers?

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Electrochemical reactions involve the transfer of electrons . Mass and charge are conserved when balancing these reactions, but you need to know which atoms are oxidized and which atoms are reduced during the reaction. Oxidation numbers are used to keep track of how many electrons are lost or gained by each atom. These oxidation numbers are assigned using the following rules.

Rules for Assigning Oxidation Numbers

  • The convention is that the cation is written first in a formula, followed by the anion . For example, in NaH, the H is H-; in HCl, the H is H+.
  • The oxidation number of a free element is always 0. The atoms in He and N 2 , for example, have oxidation numbers of 0.
  • The oxidation number of a monatomic ion equals the charge of the ion. For example, the oxidation number of Na + is +1; the oxidation number of N 3- is -3.
  • The usual oxidation number of hydrogen is +1. The oxidation number of hydrogen is -1 in compounds containing elements that are less ​ electronegative than hydrogen, as in CaH 2 .
  • The oxidation number of oxygen in compounds is usually -2. Exceptions include OF 2 because F is more electronegative than O, and BaO 2 , due to the structure of the peroxide ion, which is [O-O] 2- .
  • The oxidation number of a Group IA element in a compound is +1.
  • The oxidation number of a Group IIA element in a compound is +2.
  • The oxidation number of a Group VIIA element in a compound is -1, except when that element is combined with one having a higher electronegativity. The oxidation number of Cl is -1 in HCl, but the oxidation number of Cl is +1 in HOCl.
  • The sum of the oxidation numbers of all of the atoms in a neutral compound is 0.
  • The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion. For example, the sum of the oxidation numbers for SO 4 2- is -2.
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COMMENTS

  1. PPT

    Presentation Transcript. Rules for assigning Oxidation numbers: 1. All elements in their free state (uncombined with other elements) have an oxidation number of zero (e.g. Na, Cu, Mg, H2, O2, Cl2, N2) 2. His +1except in metal hydrides, where it is -1 (e.g. NaH, CaH2) 3. Ois -2, except in peroxides, where it is -1, and in OF2, where it is +2.

  2. oxidation numbers

    The oxidation number of Cl is -1 in HCl, but the oxidation number of Cl is +1 in HOCl. 9. The sum of the oxidation numbers of all of the atoms in a neutral compound is 0. 10. The sum of the oxidation numbers in a polyatomic ion is equal to the charge of the ion. For example, the sum of the oxidation numbers for SO4 2- is -2.

  3. PPT OXIDATION STATES

    OXIDATION STATES RULES FOR ASSIGNING OXIDATION STATES Group one elements are always 1+ in compounds or asfree (aq) ions. Ex in NaCl EACH Na has an oxidation state of 1+. in K2SO4 EACH Na has an oxidation state of 1+. A Li+1 (aq) free ion has an oxidation number of 1+. OXIDATION STATES 2) Group two elements have an oxidation state of 2+ in ...

  4. PDF Lecture 11. Redox Chemistry

    Steps for relating half-reaction voltages and activities from the Nernst Equation (4 or 5): Write a balanced half-reaction (see below rules in assigning oxidation numbers). Determine. Gr (from tabulated. Gf values, using molar coefficients and. Gf of e- = 0) c. Determine Eh o from Gr , or a given value of K. d.

  5. Oxidation numbers

    The oxidation number of Al subtract four equals -1. Therefore the oxidation number of Al is +3. 3. Work out the oxidation numbers for the elements in the following molecules by first assigning δ- and δ+ charges. a) NBr 3 b) BeCl 2 c) BI 3 d) CH 3 OH e) HO- f) H 2 PO 4 - You should now learn the rules for assigning oxidation numbers ...

  6. Rules assign oxidation numbers

    1 of 8. Download Now. Download to read offline. Rules assign oxidation numbers - Download as a PDF or view online for free.

  7. 22.6: Assigning Oxidation Numbers

    Assigning Oxidation Numbers. The oxidation number is a positive or negative number that is assigned to an atom to indicate its degree of oxidation or reduction. In oxidation-reduction processes, the driving force for chemical change is in the exchange of electrons between chemical species. A series of rules have been developed to determine ...

  8. Oxidation Numbers

    Description. This 15-slide PowerPoint lesson on Oxidation Numbers begins by reviewing redox reactions. It then outlines oxidation numbers before describing the rules used to assign oxidation numbers. The lesson package concludes by checking students' understanding. There are 2 videos embedded in the PowerPoint.

  9. Oxidation numbers

    medicinal chemistry -l. lecture 12 ppt.pptxB Pharmacy fourth semester second ... Assign oxidation number to hydrogen Find oxidation number of carbon. CH4 X +1 X+4x(+1)=0 (Hint: Total of oxidation numbers for a compound must be equal to 0) X+4=0 X=-4 6.

  10. Oxidation Numbers Powerpoint Teaching Resources

    Browse oxidation numbers powerpoint resources on Teachers Pay Teachers, a marketplace trusted by millions of teachers for original educational resources.

  11. Redox and Assigning Oxidation Numbers

    Download ppt "Redox and Assigning Oxidation Numbers" Similar presentations ... Topic: Intro to Redox: Assigning Oxidation Number Do Now: What is oxidation number for the following Metals in the ionic compounds below 1.Fe 2 O 3 2.FeO. REDOX Oxidation and Reduction Chapters 20 and 21.

  12. PDF Oxidation Numbers: Rules

    7) The oxidation number of Group 1A elements is always +1 and the oxidation number of Group 2A elements is always +2. 8) The oxidation number of oxygen in most compounds is -2. 9) Oxidation numbers for other elements are usually determined by the number of electrons they need to gain or lose to attain the electron configuration of a noble gas.

  13. PPT

    Assigning Oxidation Numbers. Section 2 Oxidation Numbers. Chapter 7. Assigning Oxidation Numbers. In general when assigning oxidation numbers, shared electrons are assumed to " belong " to the more electronegative atom in each bond. More-specific rules are provided by the following guidelines. 61 views • 4 slides

  14. 11.3: Oxidation States: Electron Bookkeeping

    Assign oxidation numbers to the atoms in each substance. Br 2; SiO 2; Ba(NO 3) 2; Solution. Br 2 is the elemental form of bromine. Therefore, by rule 1, each atom has an oxidation number of 0. By rule 3, oxygen is normally assigned an oxidation number of −2. For the sum of the oxidation numbers to equal the charge on the species (which is ...

  15. PPT

    Rules for assigning Oxidation numbers • The oxidation number of free elements is always zero (Example: Cl0, Mg0, H20) • This includes diatomic elements (H2 N2 F2 O2 I2 Cl2 Br2) and certain molecular substances (P4 and S8) • A good way to remember these elements is with the phrase "BrINClHOF". Continued 2. The oxidation number of a ...

  16. Oxidation Numbers

    This 15-slide PowerPoint lesson on Oxidation Numbers begins by reviewing redox reactions. It then outlines oxidation number before describing the rules used to assign oxidation numbers. The lesson package concludes by checking students' understanding. There are 2 videos embedded in the PowerPoint. S...

  17. Rules for Assigning Oxidation Numbers (OpenChem)

    The LibreTexts libraries are Powered by NICE CXone Expert and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739.

  18. Assigning Oxidation Number

    The oxidation number of F is -1 in all its compounds. 2+ 1-Mg F2 5.The sum of the oxidation numbers of all of the atoms in a polyatomic ion is equal to the ionic charge of the complex ion. Ex: (+3)+(-2)=1 +1 -2 + HO 3 6.The oxidation number of oxygen is always -2, except in peroxides (H2O2) where it is -1, and when it combined with fluorine ...

  19. 2.6.1 oxidation numbers

    3 likes • 13,536 views. M. Martin Brown. Education. 1 of 20. Download Now. Download to read offline. 2.6.1 oxidation numbers - Download as a PDF or view online for free.

  20. Rules for Assigning Oxidation Numbers

    The convention is that the cation is written first in a formula, followed by the anion. For example, in NaH, the H is H-; in HCl, the H is H+. The oxidation number of a free element is always 0. The atoms in He and N 2, for example, have oxidation numbers of 0. The oxidation number of a monatomic ion equals the charge of the ion.