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Introduction to REDOX
Oxidation and reduction in terms of electron transfer
Definitions
LEO the lion says GER or OIL RIG
Definitions
- Oxidation is loss of electrons.
- Reduction is gain of electrons.
LEO the lion says GER or OIL RIG
Assigning Oxidation Numbers
When an oxidation number is assigned to the element, it does not imply that the element in the compound acquires this as a charge, but rather that it is a convenient number to use for balancing chemical reactions. The guidelines for assigning oxidation states (numbers) are given below:
The oxidation state of any element such as Fe, H2, O2, P4, S8 is zero (0). The oxidation state of oxygen in its compounds is -2, except for peroxides like H2O2, and Na2O2, in which the oxidation state for O is -1. The oxidation state of hydrogen is +1 in its compounds, except for metal hydrides, such as NaH, LiH, etc., in which the oxidation state for H is -1. The oxidation states of other elements are then assigned to make the algebraic sum of the oxidation states equal to the net charge on the molecule or ion. The following elements usually have the same oxidation states in their compounds:
- +1 for alkali metals - Li, Na, K, Rb, Cs;
- +2 for alkaline earth metals - Be, Mg, Ca, Sr, Ba;
- -1 for halogens except when they form compounds with oxygen or one another;
Class Handouts
assigning_oxidation_numbers.pdf | |
File Size: | 61 kb |
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balancing_redox_equations.pdf | |
File Size: | 57 kb |
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oa_and_ra_table.pdf | |
File Size: | 53 kb |
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