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chem lecture ch15
Question | Answer |
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Brønstedt-Lowry acids and bases | Arrhenius defined, that acid-base neutralizations are reactions in which an acid and a base combine forming water and a salt.views acid-base reactions as proton transfers. An acid is a proton donor. A base is a proton acceptor. |
conjugate acid-base pair | Two substances that differ from each other by only one proton |
Amphoteric substances | substances (molecules, ions) that can react as either acids or bases |
define strength of an acid | its ability to donate a proton to a base. We measure the strength by determining the progress of this reaction towards completion. A reference base is needed to compare different acids, water is the reference of choice. |
define a strong acid | one that is completely converted to a new acid, the hydronium ion. Accordingly, H3O+ is the strongest acid in water. |
define a weak acid | one that produces two acidic species. |
When two amphoteric substances are mixed...? | the stronger acid will react as an acid, the stronger base as a base. |
Binary acids | acids that consist of hydrogen and a nonmetal.The strength of the binary acids increase from the left to the right within a period. The strength of the binary acids increase from the top to the bottom within a group. |
oxoacids | Acids composed of hydrogen, oxygen and some other element. All structures of oxoacids have O-H groups, which donate the protons. The acidity of the protons is determined by the polarity of the O–H bond. |
how does electronegativity of the central atom affect the acidity of an oxoacid? | As the electronegativity of the central atom increases, the acid becomes stronger. |
Lewis acid | any ionic or molecular species that can accept a pair of electrons in the formation of a coordinate covalent bond. have valence orbitals, that are not completely filled such as BF3 or H+. |
Lewis base | any ionic or molecular species that can donate a pair of electrons in the formation of a coordinate covalent bond. have completely filled valence orbitals and unshared pairs of electrons |
acidic anhydrides | Nonmetal oxides that react with water and give acidic solutions. |
how does the oxidation number of a metal influence acid-base properties? | As the oxidation number on a metal ion increases, the metal ion becomes more acidic, it becomes a better electron pair acceptor. Examples: Na2O CaO Al2O3 CrO3 |
define Acidic and basic solutions in terms of relative concentrations of hydronium and hydroxide ions. | Neutral solution: [ H3O+ ] = [ OH- ] Acidic solution: [ H3O+ ] > [ OH- ] Basic solution: [ H3O+ ] < [ OH- ] |
pH basic formulas | pH = -log [ H+ ] [ H+ ] = 10^-pH Ion product constant KW = [ H+ ] [ OH- ] at 25 °C pKW = pH + pOH = 14 at 25 °C |
Contributors to the proton concentration in an acid (formula) | [ H+ ]total = [ H+ ]solute + [ H+ ]water |