Chapter 14 Section 1 – Properties of Acids and Bases Section 2 – Acid Base Theories Section 3 – Acid Base Reactions
14.1 Properties of Acids and Bases List five general properties of aqueous acids and bases. Name common binary acids and oxyacids, given their chemical formulas. List five acids commonly used in industry and the laboratory, and give two properties of each. Define acid and base according to Arrhenius’s theory of ionization. Explain the differences between strong and weak acids and bases.
Properties of: Acids Bases • Sour taste • Conducts electricity • Turns litmus paper red • Reacts with bases to produce salts and water • Reacts with some metals and releases hydrogen gas • Can you think of a reaction that this occurs? Bitter taste Feels slippery Conducts electric current Turns litmus paper blue Reacts with acids to produce salts and water
Binary Acids • Contains only two different elements • Hydrogen and an electronegative element (usually a halogen) • Nomenclature: hydro - _________ - ic acid
Oxyacid Contains hydrogen, oxygen, and a third element(hydrogen with a polyatomic ion) Nomenclature:
Common Industrial Acids • Sulfuric Acid • Sulfuric acid is the most commonly produced industrial chemical in the world. • Nitric Acid • Phosphoric Acid • Hydrochloric Acid • Concentrated solutions of hydrochloric acid are commonly referred to as muriatic acid. • Acetic Acid • Pure acetic acid is a clear, colorless, and pungent-smelling liquid known as glacial acetic acid.
Arrhenius Acids and Bases • Arrhenius Acids: • Increases concentration of H+ ions in solution • Arrhenius Bases: • Increases concentration of OH- ions in solution
Arrhenius Acids Molecular compounds with ionizable hydrogen atoms Water solutions are known as aqueous acids Electrolytes
Acid Strength • Strong acid: • Ionizes completely in solution and is an electrolyte • Example: HCl, HClO4, HNO3 • Weak acid: • Releases few hydrogen ions in solution • Hydronium ions, anions and dissolved acid molecules present • Examples: HCN, Organic acids – HC2H3O2
Base Strength • Strong bases: • Ionic compounds containing metal cation and hydroxide ion (OH-) • Dissociates in water • Weak bases: • Molecular compounds do not follow Arrhenius definition: • Ammonia (NH3) • Produces hydroxide ions when it reacts with water molecules
Acidic solution has greater [H3O+] Basic solution has greater [OH–]
14.2 Acid Base Theories Define and recognizeBrønsted-Lowryacids and bases. Define a Lewis acid and a Lewis base. Name compounds that are acids under the Lewis definition but are not acids under the Brønsted-Lowry definition.
Bronsted-Lowry Acid • Bronsted-Lowry Acid: • Proton (H+) donor • Hydrogen chloride acts as a Bronsted-Lowry acid when it reacts with ammonia. • Water can also act as a Bronsted-Lowry acid
Bronsted-Lowry Base • Bronsted-Lowry Base: • Proton acceptor • Ammonia accepts a proton from hydrochloric acid. • Hydroxide ions produced in solution act as a Bronsted-Lowry base
Bronsted-Lowry Acid Base Reactions acidbase Protons are transferred from one reactant (the acid) to another (the base)
Monoprotic Acids Can donate only one proton (hydrogen ion) per molecule One ionization step
Polyprotic Acids 1. 2. • Donates more than one proton per molecules • Multiple ionization steps • Diprotic – donates 2 protons Ex: • Triprotic – donates 3 protons Ex: Sulfuric acid solutions contain H3O+, HSO4-, SO4- ions
Lewis Acid • Lewis acid: • Atom, ion, or molecule that ACCEPTS an ELECTRON PAIR to form a covalent bond • A proton (hydrogen ion) is a Lewis acid • Lewis base: • Atom, ion, or molecule that DONATES an ELECTRON PAIR to form a covalent bond
Lewis Acid A lewis acid might not include hydrogen Silver as a lewis acid:
14.3 Acid Base Reactions Describe a conjugate acid, a conjugate base, and an amphoteric compound. Explain the process of neutralization. Defineacid rain, give examples of compounds that can cause acid rain, and describe effects of acid rain.
Conjugate Acid – Base acid conjugate base • Conjugate Base: • The species that remains after a Bronsted-Lowry acid has given up a proton • Conjugate Acid: • The species that remains after a Bronsted-Lowry base has accepted a proton
Conjugate Acid Base Pairs acid1base2conjugate base1 conjugate acid2 Match up the acid-base pairs (proton donor-acceptor pairs)
Strength of Acid Base Pairs strong acid base acid weak base The stronger the acid, the weaker the conjugate base The stronger the base, the weaker the conjugate acid
Proton transfer favors the production of the weaker acid and base. stronger acid stronger base weaker acid weaker base weaker acid weaker base stronger acid stronger base
Amphoteric acid1 base2 acid2base1 base1acid2acid1 base2 Any species that can react as either an acid or base Example: water
Amphoteric Compounds Covalently bonded –OH group in an acid is referred to as a hydroxyl group Molecular compounds with hydroxyl groups can be acidic or amphoteric The behavior of the compound is affected by the number of oxygen atoms bonded to the atom connected to the –OH group
Neutralization Reactions • What does it mean to neutralize something? • Neutralization reactions: • Hydronium and hydroxide ions react to form water • The left over cation and anion in solution produce a salt (ionic compound)
Acid Rain NO, NO2, CO2, SO2, and SO3 gases from industrial processes can dissolve in atmospheric water to produce acidic solutions. Very acidic rain is known as acid rain. Acid rain can erode statues and affect ecosystems.
Chapter 15 Section 1 – Aqueous Solutions and the Concept of pH Section 2 – Determining pH and Titrations
15.1 Aqueous Solutions and pH Describe the self-ionization of water. Define pH, and give the pH of a neutral solution at 25°C. Explain and use the pH scale. Given [H3O+] or [OH−], findpH. GivenpH,find [H3O+] or [OH−].
Self Ionization of Water • Two water molecules produce a hydronium ion and hydroxide ion by proton transfer • In water at 25°C, [H3O+] = 1.0 ×10−7 M and [OH−] = 1.0 × 10−7 M • The ionization constant of water,Kw Kw = [H3O+][OH−]