Acids and Bases Chapter 19

Naming Acids Binary Acids- two different elements in the formula, H is one of them Prefix= hydro Root= second element ends in -ic Common Acids found on TABLE K

Binary Acids HF HBr HCl HI H2SH2S

Ternary Acids H with a polyatomic ion, contains 3+ different elements 1)Polyatomic ion ends in -ate Name of acid ends in -ic H 2 SO 4 = sulfuric acid “I ate until I got ‘ic!”

Ternary Acids 2) Polyatomic ends in -ite –Name of acid ends in -ous –H 2 SO 3 = sulfurous acid –“Ite thought of ous.”

H 2 CO 3 H 3 PO 4 HClO HNO 3 HClO 3 HClO 2 HC 2 H 3 O 2 Carbonic acid Phosphoric acid Hypochlorous acid Nitric acid Chloric acid Chlorous acid Acetic acid

Naming Bases Name the metal followed by the word “hydroxide” “strong bases” include a metal from Groups 1 or 2 Common Bases found in TABLE L

NaOH KOH Ca(OH) 2 NH 4 OH Ba(OH) 2 Sodium hydroxide Potassium hydroxide Calcium hydroxide Ammonium hydroxide Barium hydroxide

General Info Acids and Bases are ELECTROLYTES Dilute acid solutions taste sour Dilute base solutions taste bitter Aqueous solutions of bases feel slippery Acids and bases cause color changes in solutions of substances known as acid- base indicators (Table M)

Acids react with certain metals to produce Hydrogen gas (H 2(g) ) Zn (s) +HCl (l)  H 2(g) + ZnCl 2(s) Metal acid gas salt Table J- Activity Series Single Replacement Rxn

Acids and Bases Neutralize each other to produce a salt and water HCl + NaOH  NaCl + H 2 O acid base salt water

Arrhenius Theory One explanation for behavior of acids and bases Theory states that acids and bases are electrolytes (conduct electricity when dissolved in H 2 O)

Arrhenius Acids Only (+) ion in solution is H + –Characteristic properties of acids are due to excess H + –HCl  H + + Cl -

Arrhenius Bases Only (-) ion in solution is OH - –Characteristic properties of bases are due to excess OH - –NaOH  Na + + OH -

Bronsted-Lowry Theory ACIDS: Proton (H + ) donor BASES: Proton (H + ) acceptor NH 3 + H 2 O  NH OH - Water donates a proton to ammonia –Water is the acid NH 3 accepts the proton from water –Ammonia (NH 3 ) is the base

HCl + H 2 O  H 3 O + + Cl - HCl donates a proton to water –HCl is the acid H 2 O accepts the proton from HCl –H 2 O is the base

Water acted as an acid, then a base?! AMPHOTERIC or AMPHIPROTIC –Substances that can act as either an acid or a base, depending on who they are mixed with (environment)

In in the presence of: A strong base, acts as an acid A strong acid, acts as a base Examples: water, HSO 4 -, HS -, HPO 4 2-

Lewis Theory Gilbert Lewis ( ) Proposed that an acid accepts a pair of electrons during a reaction, while a base donates a pair of electrons

Lewis Theory Lewis Acid: a substance that can accept a pair of electrons to form a covalent bond. Lewis Base: a substance that can donate a pair of electrons to form a covalent bond.

Acid-Base Reactions Neutralization rxns occur when equivalent quantities of an acid and a base are mixed. H + + OH -  H 2 O All neutralization rxns involve combining a hydrogen ion with hydroxide ion to make water DOUBLE REPLACEMENT

Write the equation for the neutralization reaction of each 1)Hydrochloric acid by sodium hydroxide 2)Nitric acid by potassium hydroxide 3)Sulfuric acid by calcium hydroxide 4)Phosphoric acid by sodium hydroxide 5)Carbonic acid by calcium hydroxide

Conjugate Acid-Base Pairs A Bronsted-Lowry concept in which two substances differ by a proton (H + ) **Acids donate/Bases accept** HCl + H 2 O Cl - + H 3 O + acid base base acid Conjugate Pair 1: HCl and Cl - Conjugate Pair 2: H 2 O and H 3 O +

Conjugate Acid Base Pair ID practice 1.CH 3 COO - + H 3 O + CH 3 COOH + H 2 O 2.HCl + H 2 O H 3 O + + Cl - 3.NH H 2 O NH 3 + OH - 4.CN - + H 2 O HCN + OH -

Strongest acids have the weakest conjugate bases Strongest bases have the weakest conjugate acids

Acid-Base Titrations Used to determine an unknown concentration of either an acid or a base Must determine the volumes of acid and base involved Standard Solution: the acid or base of a known molarity (concentration IS known) End point: use an indicator to know when to stop

Titration Calculations M A V A = M B V B –M A : molarity of acid –V A : volume of acid –M B : molarity of base –V B : volume of base

Examples 1.How many mL of 0.2 M KOH are needed to neutralize 20 mL of 0.1 M HCl? 2.If 6 mL of 1.0 M HCl is neutralized by 3 mL of KOH, the molarity of KOH is…? 3.How many mL of 0.15 M KOH are needed to neutralize 14 mL of 0.5 M HCl?

pH Hydrogen ion concentration Used to determine the acidity or basicity of a substance on a scale of 0-14

NEUTRAL: [OH - ] = [H + ]

Strong  ionizes (dissociates) completely HCl into water All dissociate in solution HCl  H + + Cl - Strong acid

HC 2 H 3 O 2 into water Does not dissociate completely Still have HC 2 H 3 O 2 in solution Weaker acid

NaOH into water All dissociate into water NaOH  Na + + OH - Strong base

6 Strongest Acids (Memorize them!!!) HClO 4 perchloric acid HI hydroiodic acid HBr hydrobromic acid HCl hydrochloric acid H 2 SO 4 sulfuric acid HNO 3 nitric acid

Strongest Bases Hydroxides bound to Group 1 or Group 2 metals