Section 2-4: Writing and Naming Acids and Bases

Section 2.4—Defining, Naming & Writing Acids & Bases :Section 2.4—Defining, Naming & Writing Acids & Bases We need to know what acids behave when talking about ant-acids!


Acids :Acids


Acids – Arrhenius Definition :Acids – Arrhenius Definition Produce Hydronium ion (H3O+1) in water Hydronium ion is water + a hydrogen cation By this definition, if an acid is to give a H+1 to water, then all acids will have hydrogen as the cation (first element written).


How do Acids produce Hydronium? :How do Acids produce Hydronium? water acid Hydrogen cation with some anion


How do Acids produce Hydronium? :How do Acids produce Hydronium? +1


How do Acids produce Hydronium? :How do Acids produce Hydronium? +1 Hydronium ion Anion


Naming Acids :Naming Acids


Naming non-oxygen Acids :These compounds have: Start with “H” (more than 1 “H” is OK, too). Do not contain oxygen To name these compounds: Use “hydro____ic acid” Fill in the blank with the anion’s name without the last syllable Naming non-oxygen Acids


Example #1 :Example #1 HBr


Example #1 :Example #1 HBr Hydrogen cation Bromine It’s an acid No oxygen Use “hydro___ic” Hydrobromic acid


Naming Oxygen Acids :These compounds have: Start with “H” (more than 1 “H” is OK, too). Do contain oxygen To name these compounds: Use “___ic acids” for “-ate” anions Use “___ous acids” for “-ite” anions Naming Oxygen Acids Do not use “hydro” with these…the word “acid” is how you know it begins with hydrogen, not “hydro-”


Example #2 :Example #2 H2SO3


Example #2 :Example #2 Hydrogen cation Sulfite ion It’s an acid “-ite” ion Use “___ous” acid H2SO3 Sulfurous acid


Example #3 :Example #3 H2SO4


Example #3 :Example #3 Hydrogen cation Sulfate ion It’s an acid “-ate” ion Use “___ic” H2SO4 Sulfuric acid


Let’s Practice :Let’s Practice Example: Write the name for the following compounds HCl HNO3 H2S H3PO3


Let’s Practice :Let’s Practice Hydrochloric acid Nitric acid Hydrosulfuric acid Phosphorous acid Example: Write the name for the following compounds HCl HNO3 H2S H3PO3


Writing Acid Formulas :Writing Acid Formulas


“Hydro-” acids :To write these formulas: The cation is H+1 Write the anion and charge Balance the charges by adding the appropriate subscript to the hydrogen cation “Hydro-” acids


Example #4 :Example #4 Hydrofluoric acid


Example #4 :Example #4 Hydrofluoric acid Hydrogen cation Does not contain oxygen H+1 F-1


Example #4 :Example #4 Hydrofluoric acid Hydrogen cation Does not contain oxygen H+1 F-1 HF H+1F-1 +1 + -1 = 0 The compound is neutral. Subscripts are not needed


NON “Hydro-” acids :To write these formulas: The cation is H+1 If it is an “-ic” acid, the anion is the “-ate” polyatomic ion If it is an “-ous” acid, the anion is the “-ite” polyatomic ion Add subscript to the hydrogen cation to balance charges NON “Hydro-” acids


Example #5 :Example #5 Carbonic acid


Example #5 :Example #5 Carbonic acid Hydrogen cation From the “___ate” anion H+1 CO3-2


Example #5 :Example #5 Carbonic acid Hydrogen cation From the “___ate” anion H+1 CO3-2 H2CO3 H+CO32- +1 + -2 = -1 H+H+CO32- +1 + 1 + -2 = 0


Example #6 :Example #6 Nitrous acid


Example #6 :Example #6 Nitrous acid Hydrogen cation From the “___ite” anion H+1 NO2-1


Example #6 :Example #6 Nitrous acid Hydrogen cation From the “___ite” anion H+1 NO2-1 HNO2 H+NO2- +1 + -1 = 0


Let’s Practice :Let’s Practice Example: Write the formula for the following acids Phosphoric acid Hydroiodic acid Perchloric acid


Let’s Practice :Phosphoric acid Hydroiodic acid Perchloric acid Let’s Practice H3PO4 HI HClO4 Example: Write the formula for the following acids


Bases :Bases


Bases – Arrhenius Definition :Bases – Arrhenius Definition Bases produce the hydroxide ion in water Hydroxide Ion


Naming & Writing Bases :Naming & Writing Bases


Naming Bases :Most bases are just ionic compounds with “hydroxide” as their anion The most common exception to this is ammonia NH3 (ammonia) is a base even though it doesn’t contain “-OH” as the anion Naming Bases


Example #7 :Example #7 NaOH


Example #7 :Example #7 NaOH Sodium Hydroxide Sodium Hydroxide


Let’s Practice :Let’s Practice Example: Write the formula or name for each Ca(OH)2 KOH Sr(OH)2 Copper (II) hydroxide Magnesium hydroxide


Let’s Practice :Let’s Practice Calcium hydroxide Potassium hydroxide Strontium hydroxide Cu(OH)2 Mg(OH)2 Example: Write the formula or name for each Ca(OH)2 KOH Sr(OH)2 Copper (II) hydroxide Magnesium hydroxide