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Unit 8. Oxidation States. Oxidation States. Goal: Identify if a reaction is a redox reaction. Oxidation State: The charge that an atom appears to have Common sense usually prevails when assigning oxidation states. Rules for assigning oxidation state
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Unit 8 Oxidation States
Oxidation States Goal: Identify if a reaction is a redox reaction Oxidation State: The charge that an atom appears to have Common sense usually prevails when assigning oxidation states Rules for assigning oxidation state The oxidation number of ANY element in its most stable form is ALWAYS 0. Examples: Fe(s), O2, Cl2, F2, N2, C(s) If monoatomic ions appear in the equation (e.g. Na+), the charge is the oxidation state. Group IA = +1 and Group IIA = +2. Halogens are usually -1. Oxygen is usually -2. Exceptions: O2 = 0 and H2O2 = -1. Hydrogen is usually +1. Exceptions: H2 = 0 and when bonded to a metal (NaH) = -1. Binary Compounds: most electronegative has its charge as an anion (e.g. F = -1, O = -2, etc.) and cationbalances the charge
Oxidation State Rules for assigning oxidation state The oxidation number of ANY element in its most stable form is ALWAYS 0. Examples: Fe(s), O2, Cl2, F2, N2, C(s) If monoatomic ions appear in the equation (e.g. Na+), the charge is the oxidation state. Group IA = +1 and Group IIA = +2. Halogens are usually -1. Oxygen is usually -2. Exceptions: O2 = 0 and H2O2 = -1. Hydrogen is usually +1. Exceptions: H2 = 0 and when bonded to a metal (NaH) = -1. Binary Compounds: most electronegative has its charge as an anion (e.g. F = -1, O = -2, etc.) and cationbalances the charge Cl2 FeH2 CH2O NH3 NH4+
Oxidation State Rules for assigning oxidation state The oxidation number of ANY element in its most stable form is ALWAYS 0. Examples: Fe(s), O2, Cl2, F2, N2, C(s) If monoatomic ions appear in the equation (e.g. Na+), the charge is the oxidation state. Group IA = +1 and Group IIA = +2. Halogens are usually -1. Oxygen is usually -2. Exceptions: O2 = 0 and H2O2 = -1. Hydrogen is usually +1. Exceptions: H2 = 0 and when bonded to a metal (NaH) = -1. Binary Compounds: most electronegative has its charge as an anion (e.g. F = -1, O = -2, etc.) and cationbalances the charge NO2- NO3- CH4 CCl4
Oxidation State Rules for assigning oxidation state The oxidation number of ANY element in its most stable form is ALWAYS 0. Examples: Fe(s), O2, Cl2, F2, N2, C(s) If monoatomic ions appear in the equation (e.g. Na+), the charge is the oxidation state. Group IA = +1 and Group IIA = +2. Halogens are usually -1. Oxygen is usually -2. Exceptions: O2 = 0 and H2O2 = -1. Hydrogen is usually +1. Exceptions: H2 = 0 and when bonded to a metal (NaH) = -1. Binary Compounds: most electronegative has its charge as an anion (e.g. F = -1, O = -2, etc.) and cationbalances the charge Cr2O72- CrO42-