CHEM 122 11th EditionExam #4 Study Guide Lectures: 24-30Lecture 24: (March 23rd)Acids and Bases- Arrhenius’s Definitiono Acid: a substance that increases the hydrogen ion concentration in watero Base: a substance that increases the hydroxide ion concentration in water- Bronsted’s Definitiono Acid: a substance that transfers a hydrogen ion to another substance. (Proton donor)o Base: a substance that accepts a hydrogen ion from another substance (proton acceptor). - Characteristics of Acids:o Have a sour tasteo Turns litmus paper redo React with many metals to release diatomic hydrogen- Characteristics of Bases:o Have a bitter tasteo Have a slippery feelo Turns litmus paper blue- Short hand Notation: when water is in the equation it creates a hydronium ion. When water is added to the equation but isn’t a reactant it creates a hydrogen ion.- Amphoteric substance: a substance that can act as either an acid or a base. Water can be this.Conjugate Acid-Base Pairs: corresponding acid base pairs that only differ by one hydrogen ion.o Seven strong acids to know: HNO3: nitric acid HClO4: perchloric acid HClO3: chloric acid H2SO4: sulfuric acid HCl: hydrochloric acid HBr: Hydrobromic acid HI: Hydroiodic acidChemical structures of Acids:- Binary Hydrides: contain hydrogen and one more elementoHaX o As you go left of the periodic table and down the acid strength increases.- Oxoacids: very common; contains one or more OH group bound to the central atom.o Ex) HClO4- 1 OH group H2SO4- 2 OH groups HNO3- 1 OH groupo Trends in acidity: For homologous series (same central atom) the acidity increases with increasing number of oxygen atoms bound to the central atom. For oxoacids that have the same number of oxygen atoms, acid strength increases with increasing electronegativity.- Carboxylic Acidso The conjugate base of a carboxylic acid is called a carboxylate anion.Lecture 25 (March 27th)Strong Bases: bases that completely dissociate to ions in a solution.- All alkali metal hydroxides are strong bases: LiOH, NaOH, KOH, RbOH and CsOH- The heavier alkaline earth metal hydroxides are strong bases: Ca(OH)2, Sr(OH)2, Ba(OH)2o Be(OH)2 and Mg(OH)2 are weak basesAcid/Base Properties of Binary Oxides:- Basic anhydrides: “Bases without water” Made from metal oxides reacting with water to form bases. - Acid Anhydrides: “Acids without water) Mae from nonmetal oxides reacting with water to form acids.Lewis Acids and Bases: focuses on the electron pairs.- Lewis Acid: An electron pair acceptor.- Lewis Base: an electron pair donor.- Lewis developed Lewis electron dot structures based on electron pairs.Autoionization of Water: pure water dissociates to yield ions.- Ion product constant: +¿H¿¿−¿OH¿¿Kw=¿ when the temperature is 25 degrees Celsius.- Electrolytic solution: aqueous solutions that contain high concentration of dissolved ionsthat conduct electricity- Nonelectrolyte solution: aqueous solutions that do not contain dissolved ions that do not conduct electricity.- If an acid is added to water, then the H+ concentration increases. The position of the equilibrium shifts to the left until the product of the ion concentrations equal Kw.- If a base is added then the OH- concentration increases and H+ decreases.pH scales for Acids and Bases: - pH= -log[H+]- as [H+] concentration decreases, pH increases.- P-function: pX= -log[X] X= any speciesLecture 2 (March 30th)Acid/Base Ionization Constants - Acid (Ka)/base (Kb) ionization constant: equilibrium constant for a weak acid/base. - General equation for weak acid dissociation:−¿(aq)+¿(aq)+A¿HA(aq)❑⇔H¿- General equation for base ionization constant: −¿(aq)+¿(aq)+O H¿B(aq)+H2O(l)❑⇔B H¿- For any conjugate acid-base pair: Ka x Kb = Kw =1.0x10^-14- Calculations of weak acid and base solutions:o calculate Ka or Kb from initial concentration of acid or base and the known of pH [H+] of the solutiono calculate equilibrium concentrations given Ka or Kb and initial concentrations.  Write out the equilibrium law and create an ICE table to find the equilibrium concentrations.o Substitute the equilibrium concentrations expression into the Ka expression to find KaLecture 27 (April 1)Percent Ionization: % ionization= Ionized concentration/ initial concentration x 100Calculations of Weak Acid and Base Solutions:- First write out the acid ionization equilibrium equation- Second write out the equilibrium law- Third find the concentrations using ICE table- Used x to find the concentrations, then use those to find the pH and the % ionization - As the concentration of the acid is reduce the equilibrium shifts to the right. Thisis a general feature of all equilibriums.- As the % ionization increases the concentrations decrease.- The process is the same for bases except you are calculating the OH- concentration directly.Polyprotic Acids: acids with more than once acidic hydrogen atom- Monoprotic acid: acids with only one acidic hydrogen.- Polyprotic acids ionize in successive steps, losing an H+ each step.- Ka decreases for each step.Lecture 28: (April 8th)Calculating Polyprotic Acids:If Ka1 is more that 10^3 greater than Ka2, then we can treat the acid as a simple monoprotic acid. - [H+]equil.= [H+]first + [H+]second- if [H+]first>>> [H+]second then [H+]equil.= [H+]firstProperties of Solutions of Salts:- Salt: an ionic compoundo Excludes anions with OH- or O2-o Excludes cations with H+- Acid Base or Neutral?o Find the ions of the dissolved saltso Alkali metal ions do not react with water therefore they do not effect the pHo For Cations, add an H+ and decide if it becomes a strong base or weak base. Weak base has a conjugate weak acid, creating an acidic solutiono For Anions, add an H+ ion and decide if it becomes a strong acid or weak acid.Lecture 29 (April 10th)Buffer Solutions: resists changes in pH upon addition of strong acid or strong bases- A buffer solution consists of both an acidic and basic species is called a conjugateweak acid/base pair.- Neutralization reaction: base is neutralized by the weak base or vice versa.- Ideal Buffer: equal concentrations of the conjugate acid/base pair and will also have the optimum pH value.- The pH of a buffer is determined by two factors:o Ka of the weak acido Relative concentrations of weak acid/base conjugate pair.- Henderson-Hasselbalch equation: pH=pKa + log([base]/[acid])Acid-Base Titrations: used to determine the concentration of an acid or base solution.- Based on