Intro to Acids and Bases Chapter 16.1

Properties of Acids and Bases Acids and bases have a variety of properties that help us differentiate between them. If something a neither acidic or basic, it is said to be neutral. Lets make a table to compare the properties of acids and bases

ACIDBASE Taste Slippery? Litmus Phenol- phthalein

ACIDBASE TasteSourBitter Slippery? Litmus Phenol- phthalein

ACIDBASE TasteSourBitter Slippery?NoYes Litmus Phenol- phthalein

ACIDBASE TasteSourBitter Slippery?NoYes LitmusRedBlue Phenol- phthalein

ACIDBASE TasteSourBitter Slippery?NoYes LitmusRedBlue Phenol- phthalein ColorlessRed

acid base PHENOLPHTHALEINPHENOLPHTHALEIN Page 583

Acid/Base Theories Numerous scientists have discussed the behavior of acids and bases in a chemical reaction. The two main models for acids and bases are Arrhenius and Bronsted-Lowry In many acid base reactions, H + ions are transferred to water create H 3 O +, known as the hydronium ion. Lets look at a table to compare how acids and bases behave

ACIDBASE Arrhenius Make H + ion in water Make OH - ion in water [H 3 O + ] to [OH - ] Bronsted/ Lowry

ACIDBASE Arrhenius Make H + Ion in water Make OH - Ion in water [H 3 O + ] to [OH - ] [H 3 O + ] > [OH - ][H 3 O + ] < [OH - ] Bronsted/ Lowry

ACIDBASE Arrhenius Make H + Ion in water Make OH - Ion in water [H 3 O + ] to [OH - ] [H 3 O + ] > [OH - ][H 3 O + ] < [OH - ] Bronsted/ Lowry proton (H + ) donor proton (H + ) acceptor

Examples of Acid and Base Reactions Arrhenius Acid: HNO 3 > H+ + NO 3 - Arrhenius Base: KOH > K + + OH - B-L Acid: HCl+ H 2 O >Cl - + H 3 O + B-L Base: NH 3 + H 2 O > NH OH -

Strong vs Weak Acids and Bases Acids and Bases are classified by the degree to which they dissociate as strong or weak Strong acids and bases dissociate completely, therefore, they are excellent conductors of electricity. Acids: HCl, HBr, H 2 SO 4, H 2 SO 4 Bases: NaOH, KOH Weak acids and bases dissociate partially, therefore they are only OK conductors of electricity Acids: HF, H 2 S Bases: NH 3

Concentrated vs Dilute Strong and weak refers to the amount of dissociation. Concentrated and dilute refers to the molarity of the solution. Concentration does NOT affect whether an acid or base is strong or weak.

Types of Acids There are a variety of types of acids that you need to know: Monoprotic acid: acid that can supply one H+ ion per molecule. Ex. HCl, HBr Polyprotic acid: acid that can supply more than one H+ ion per molecule. Ex. H 2 SO 4

Types of Acids Binary acid: acid composed of 2 elements (one is always H). Ex. HBr, HF Ternary acid: acid composed of hydrogen plus two other elements. Ex H 3 PO 4 An acid could be both monoprotic and binary, like HCl. However, some acids like H 2 S is only binary. An acid could be both polyprotic and ternary, like H2SO4. However, some acids like HNO3 is ternary and monoprotic.

Naming Acids: A Review Acids without oxygen Prefix hydro, name of element, change ending to ic Acids with oxygen No hydro If polyatomic has an ate ending, change the ate to ic If polyatomic has an ite ending, change the ite to ous

Conjugate Acid-Base Pairs The reaction of B-L acid and bases produces the conjugate base and acid Conjugate base- the particle formed when an acid has donated a H+ ion. It will act as the base by accepting a proton in the reverse reaction. Conjugate acid- the particle formed when a base has accepted a H+ ion. It will act as the acid by donating a proton in the reverse reaction

Examples H 2 CO 3 + H 2 O > HCO H 3 O + AcidBase C.BC.A NH 3 + H 2 O > NH OH - BaseAcid C.A. C.B.

Neutralization Reaction A neutralization reaction is a reaction between an acid and a base in a aqueous solution to produce a salt and water. A salt is an ionic compound made up of the cation from the base and the anion from the acid. Acid + Base > Salt + Water Despite the name, neutralization reactions do not always results in a neutral solution

Neutralization Reactions The reaction of a strong acid plus a weak base forms a solution that is acidic The reaction of a weak acid and a strong base forms a solution that is basic. What do you think would happen if you react a weak acid and a weak base or a strong acid and a strong base? They form a neutral solution