CHEM 1125Q 1st Edition Lecture 22 Outline of Last Lecture Ch. 15I. Changes in Volume and TemperatureOutline of Current Lecture Ch. 16II. Acids and BasesA. Bronsted Acids and BasesB. Hydrohalic AcidsC. OxoacidsD. Carboxylic AcidsE. Acid Base PropertiesIII. The pH and pOH ScalesA. The pH ScaleB. The pOH ScaleC. Ionization ConstantsD. Percent Ionization Current LectureII. Acids and BasesA. Bronsted Acids ad Basesa. As we remember from CHEM 1124Q, acids are proton donors. When an acid donates a proton, the remaining molecule is that acid’s conjugate basei. For example, OH- is the conjugate base to H2Ob. When put in water, acids and bases will reach equilibriumc. If a reaction has a large K value, then its acid must be a strong acid. If its K value is small, then it has a weak acidd. While acids are proton donors, bases are proton acceptors. When a base accepts a proton, the resulting molecule is its conjugate acidi. For example, H3O+ is the conjugate acid to H2OB. Hydrohalic Acidsa. Hydrohalic acids are any acids that contain a hydrogen atom along with a halogenb. The biggest factor for determining the strength of a hydrohalic acid is its bond strength. As you move down the periodic table, the bonds get stronger, therefore making the acid strongerc. All hydrohalic acids are strong acids except for HF which is a weak acidThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.C. Oxoacidsa. An oxoacid contains hydrogen, oxygen, and a central nonmetal atom, such as carbon or nitrogenb. To compare oxoacid strengths, divide them into two groups:i. Oxoacids with different central atoms from the same periodic group with the same oxidation number1. The one with the greater electronegativity is strongerii. Oxoacids with the same central atom but different numbers of oxygen atoms1. The more oxygens present, the stronger the acidc. The more oxygen atoms, the stronger the acidD. Carboxylic Acidsa. Carboxylic acids are an important group of organic acids that contain aregion R attached to a carboxyl group, COOHb. The conjugate base to a carboxylic acid has multiple structuresc. The anion’s stability is based on its ability to delocalize its electron density. The more stable the anion, the stronger the acid was that it came fromd. Acid strength is also dependent on the R groupE. Acid Base Propertiesa. A species is amphoteric, also known as amphiprotic, if it has the ability to act as both an acid and a base. For example, water is an amphoteric substanceb. When you add water to water, it can dissociate into hydronium (H3O+) and hydroxide (OH-) ions. This is known as the autoionization of wateri. When the H3O+ concentration is equal to the concentration of OH-, the solution is neutralii. When H3O+ > OH- it is acidiciii. When H3O+ < OH- it is basicIII. The pH and pOH ScalesA. The pH Scalea. An aqueous solution’s acidity depends on the concentration of hydronium ions it containsb. The pH of a solution can be found using the molar concentration (mol/L) of H3O+ ionsi. pH = -log[H3O+]ii. [H3O+] = 10-pHc. In pure water at 25C, it is a neutral solution with a pH of 7d. pH is not limited to a scale of 0-14. A solution can have a very high concentration of acid, resulting in a negative pH, or a very low concentration of acid, resulting in a pH of greater than 14B. The pOH Scalea. The pOH scale is just like the pH scale, except that instead of using theconcentration of hydronium, it uses the molar concentration of hydroxide ionsb. pOH, like pH, is not limited to the 0-14 scale. What matters is that when you add the pH of the acid and the pH of the base, they should equal 14 (the same applies to adding the pOH’s)C. Ionization Constantsa. Ka refers to the ionization constant for acids. The larger the Ka, the stronger the acidb. Kb refers to the ionization costant for bases. The larger the Kb the stronger the baseD. Percent Ionization a. Percent ionization is a quantitative measure of the degree of ionization of a solutionb. Percent ionization can be represented by the equation:i. Percent ionization = [H3O+]/[HA] x 100c. As the acid concentration approaches zero, the ionization approaches