Chapter 17: Acids and Bases

decreases

% Ionization ____________ as [HA]initial increases

Ionization

% ________________ = [H3O-]equil/[HA]equil

Strong Acid Weak Acid

-acid that completely ionizes -acid that partially ionizes

Properties of Binary Acids according to Molecular Structure

-acidity increases as electronegativity inceases -acidity decreases as bond strength increases (bond strength has a greater effect than electronegativity on acidity)

Strong Acids

-acids that completely ionize in aqueous solution 1. HCL (Hydrochloric acid) 2. HI (Hydroiodic acid) 3. HCLO4 (Perchloric acid) 4. HBr (Hydrobromic acid) 5. HNO3 (Nitric acid) 6. H2SO4 (Sulfuric acid)

Weak Acids

-acids that only partially ionize in aqueous solution -all acids that aren't the six strong acids

neutral; basic

-conjugate base of a strong acid generally produces a __________ solution -conjugate base of a weak acid produces a ________ solution

Anions (acid-base properties)

-conjugate bases of acids -generally act as weak bases or can be neutral

Cations (acid-base properties)

-counterions of strong bases -conjugate acids of weak bases -small, highly charged metals

Salts (acid-base properties)

-the solution can be acidic, basic, or neutral

Acid-Base Reaction

AKA Neutralization reaction Acid+Base-->Water+Salt

pH

Acidic solution: ___ *<* 7 Neutral solution: ___ *=* 7 Basic solution: ___ *>* 7

pOH

Acidic solution: ___ *>* 7 Neutral solution: ___ *=* 7 Basic solution: ___ *<* 7

inversely

Acids and Bases are __________ related (i.e. when one is stronger, the other is equally weaker)

Bronsted-Lowry Acid-Base Reaction

Base (proton acceptor) + Acid (proton donor) <--> Conjugate Acid + Conjugate Base Ex. (NH3) + (H2O) <--> (NH4+) + (OH-)

*B*. -1.079 -log(12.0)

Calculate the pH of a 12.0 M HCl solution. *A*. -1.38 *B*. -1.079 *C*. -0.778 *D*. 0.0

*B*. HPO4^2- (Base/Proton acceptor)

Dihydrogen phosphate is the conjugate acid to which of the following? *A*. PO4^3- *B*. HPO4^2- *C*. H2PO4- *D*. H3PO4

*D*. H3PO4 (Acid/Proton donor)

Dihydrogen phosphate is the conjugate base to which of the following? *A*. PO4^3- *B*. HPO4^2- *C*. H2PO4- *D*. H3PO4

Equilibrium Constant for Acid Strength

HA(aq) + H2O(l) <--> H3O+(aq) + A-(aq) *Ka = ([H3O+][A-])\[HA]*

*C*. Weak base

HCL is a strong acid, H2S is a weak acid, what would you expect for PH3? *A*. Strong acid *B*. Weak acid *C*. Weak base *D*. Strong base

*A*. PO4^3-

HPO4^2- can serve as an acid. Which of the following will result from the acidic dissociation of this ion? *A*. PO4^3- *B*. HPO4^2- *C*. H2PO4- *D*. H3PO4

acidic, basic

In a(n) __________ solution: [H+] > [OH-] In a(n) __________ solution:[H+] < [OH-]

Henderson-Hasselbalch Equation

Ka = [H+][A-]/[HA] pKa = -log([H+][A-]/[HA] pKa = -(log([H+]) + log([A-]/[HA])) pKa = pH - log([A-]/[HA]) >> *pH* = pKa + log([A-]/[HA]) <<

Ion Product Constant for Water (Kw)

Kw = [H3O+][OH-] = [H+][OH-] (Kw) at 25 deg C is Kw = 1.0 x 10^-14 In a neutral solution, like pure water: [H+] = OH- = 1.0 x 10^-7 at 25 deg C

smaller

The weaker the acid, the __________ the Ka value and the less the acid ionizes in solution

*F*. None of these

What is the pH of a 0.010 M HOac solution that has 10.0% ionization? *A*. 2 *B*. 1 *C*. 0 *D*. -1 *E*. -2 *F*. None of these

*C*. HI (Hydroiodic acid)

Which one of these is a strong acid? *A*. HCN *B*. H2SO4 *C*. HI *D*. H3P *E*. HSCN

increases

[H3O-] ____________ as [HA]initial increases

Titration

a substance of known concentration is reacted with another substance of unknown concentration

Acid (Arrhenius Definition)

a substance that produces H+ ions in aqueous solution

Base (Arrhenius Definition)

a substance that produces OH- ions in aqueous solutionc

Base (Bronsted-Lowry Definition)

accepts a proton (H+ ion and becomes a conjugate acid

Amphoteric

can act as an acid or a base (ex. Water)

acidic; acidic

cations that are the conjugate acids of weak bases produce a(n) _________ solution -cations that are small, highly charged metals produce a(n) _________ solution

Acid (Bronsted-Lowry Definition)

donates a proton (H+ ion) and becomes a conjugate base

Lewis acid

electron pair acceptor

Lewis base

electron pair donor

Properties of Oxyacids according to Molecular Structure

for electron-withdrawing groups, as electronegativity increases, acidity increases -as the number of oxygen atoms attached to Y (central atom) increases, acidity increases

Equivalence Point

just enough titrant has been added to completely react with the analyte

[H+]

pH = -log(___)

[OH-]

pOH = -log(___)

Buffer

resists pH change by neutralizing added acid or base Contains significant amounts of either: -a weak acid and its conjugate base, or -a weak base and its conjugate acid

Indicator

used to identify the equivalence point

Autoionization

where it acts as both an acid and a base to itself