Acids and Bases General Formula ACID + BASE  H 2 O + SALT A salt is an ionic ioniccompound

Comparing Acids to Bases

Naming and Writing Formulas Acids A compound that contains one or more hydrogen atoms and produces hydrogen ions (H + ) when dissolved in water Acids consist of an anion and as many H + as are necessary to make the atom electrically neutral. H n X

Arrhenius Acids and Bases In water, an Arrhenius acid produces H 3 O +, and an Arrhenius base produces OH - In water, an Arrhenius acid produces H 3 O +, and an Arrhenius base produces OH - Arrhenius’ theory showed why acids and bases: Arrhenius’ theory showed why acids and bases: 1. have similar properties 2. neutralize each other 3. produce water and salt when they combine Arrhenius’ theory could not show: Arrhenius’ theory could not show: 1. Why compounds without OH- could act as bases 2. Why reactions were not limited to occurring in water

Bronsted-Lowry Acids and Bases According to Bronsted-Lowry theory, acids are proton (H + ) donors and bases are proton acceptors (opposite of an acid) According to Bronsted-Lowry theory, acids are proton (H + ) donors and bases are proton acceptors (opposite of an acid) Protons form hydronium ions, H 3 O +, in water when they bond to polar water molecules Protons form hydronium ions, H 3 O +, in water when they bond to polar water molecules This theory: This theory: 1. expands the number of substance that can be acids and bases 2. Explains how substances without OH - can be bases

Naming Acids When an acid dissolves in water and a hydrogen ion and a simple non metal are formed HCl + H 2 O  H 3 O + + Cl - hydrogen + water  hydronium + chloride hydrogen + water  hydronium + chloride chloride ion ion chloride ion ion 1. Use the prefix hydro in front of the nonmetal 2. Change the nonmetal’s ending from ide to ic acid HCl (aq) is called hydrochloric acid

When an acid contains a polyatomic ion, the name of the acid comes from the name of the polyatomic ion. * the prefix hydro is not used to indicate a polyatomic ion is present Polyatomic ions with an ate ending……..change to ic acid HNO 3(aq) + H 2 O (l)  H 3 O + + NO 3 - Nitric acid + water  hydronium + nitrate Nitric acid + water  hydronium + nitrate ion ion ion ion Polyatomic ions with an ite ending……..change to ous acid HNO 2(aq) + H 2 O (l)  H 3 O + + NO 2 - Nitrous acid + water  hydronium + nitrite ion ion ion ion

Naming and Writing Formulas Naming Acids 1)When the anion’s name ends in -ide, the acid’s name begins with hydro- and the stem of the anion’s name ends in -ic, followed by the word acid. Example: Hydrochloric AcidHCl Anion: ChlorideCl -

Naming and Writing Formulas Naming Acids 2)When the anion’s name ends in -ite, the acid’s name is the stem of the anion with the suffix - ous, followed by the word acid. Example: Sulfurous AcidH 2 SO 3 Anion: SulfiteSO 3 2-

Naming and Writing Formulas Naming Acids 3)When the anion’s name ends in -ate, the acid’s name is the stem of the anion with the suffix -ic, followed by the word acid. Example: Nitric AcidHNO 3 Anion: NitrateNO 3 -

Naming and Writing Formulas Writing Formulas for Acids Use the rules for naming acids in reverse to write formulas for acids. Find the anion in the acid. Then, match its charge with the appropriate number of H + ions to make the formula electrically neutral.

Naming Bases Name the metal (cation) by its elemental name Name the metal (cation) by its elemental name Name the simple nonmetal (anion) with the ide ending Name the simple nonmetal (anion) with the ide ending Name the polyatomic ion as is (example OH - is hydroxide) Name the polyatomic ion as is (example OH - is hydroxide)

An ionic compound that produces hydroxide ions (OH - ) when dissolved in water. These are named in the same way as other ionic compounds: cation first and anion second. Common Bases NaOHSodium Hydroxide Ba(OH) 2 Barium Hydroxide Ca(OH) 2 Calcium Hydroxide Names and Formulas for Bases

pH Scale The amount of H 3 O + ions in solution determines whether a solution is an acid or base. pH measures the concentration of H + ions in a solution

pH Scale Strong ACIDS weak weak BASES strong neutral neutral Concentration of H 3 O + ions (moles/litre) Acids increase Bases decrease p+ concentration

In aqueous solution, a strong acid donates nearly all of its protons to water, whereas a weak acid donates only a small percentage of protons to water. Most hydroxides of Groups 1A and 2A are strong gases, which dissociate nearly completely in water Adding water equalizes the strength of all strong acids/bases = levelling effect

Conjugate Pairs Acids and bases react differently but are connected in similar reactions Acids and bases react differently but are connected in similar reactions Once an acid donates a proton it is then able to accept another proton Once an acid donates a proton it is then able to accept another proton = conjugate acid-base pair (strengths are inverse) = conjugate acid-base pair (strengths are inverse)

Practice Page 218, #1-3 Page 218, #1-3 Page 225, #1-3 Page 225, #1-3 Page 230, #1-4 Page 230, #1-4 Page 236, #1-4 Page 236, #1-4