AP Chemistry -- Chapter 14 : Acids and Bases

Arrhenius acids

produce hydrogen ions in water

Arrhenius bases

produce hydroxide ions in water

when concerning acids and bases, what does it mean when something produces hydrogen or hydroxide ions

it increases the concentration of it

what is the pH range for acids

up to 6.9

what is the pH range for bases

7.1 and up

what is the pH for a neutral solution

7

what is a bronsted-Lowry model acid

proton donor

what is a Bronsted-Lowry model base

proton acceptor

what is another name for hydrogen ions

proton

what is something that sometimes appears in place of a hydrogen ion but it is the same thing

a hydronium ion (H3O)

conjugate acid-base pairs

consists of stwo substances related to each other by the donating and accepting of a single proton (Ex: HCL is an acid and Cl- is its conjugate base)

how does HCl dissociate

HCl -> H+ + Cl-

how does acetic acid dissociate

HC2H3O2 --> H+ + C2H3O2-

what are the strong acids

HCl, HBr, HI, HNO3, H2SO4, HClO4, HClO3

why are some acids considered strong

they have very high Ka values and therefore at equilibrium, they have higher concentrations of products, this means that they dissociate entirely in aqueous solutions

if the Ka of an unknown acid is large, what can we assume about the properties of the acid

it is a strong acid

if the Ka of an unknown acid is small, what can we assume about the properties of the acid

it is a weak acid

what will be the relative strength of a conjugate base of a strong acid

weak base

what will be the relative strength of a conjugate base of a weak acid

strong base

what will be the relative strength of a conjugate acid of a strong base

weak acid

what will be the relative strength of a conjugate acid of a weak base

strong acid

what is Ka

the equilibrium constant for an acid

what is Kb

the equilibrium constant for a base

what is Kw

the equilibrium constant for water

what reaction does kw come from

autoionization of water (H2O +H2O --> H3O+ + OH-)

what is the formula for Kw

Kw = [H3O+][OH-]

what is the value of Kw at 25* C

1 x 10^-14

strong acid

acid characterized by its tendency to dissociate completely in water, determined by the nature of the compounds

list the following bases in decreasing strength, H2O, F-, Cl-, NO2-, CN-

CN-, F-, NO2-, H2O, Cl-

amphiprotic

acts as both and acid and a base, depending on the reaction it is involved in

autoionization

water automatiaclly dissociates or ionized with itself

what is an example of an amphiprotic compound

H2O

weak acids have low Ka values, but what are they all larger than

Kw

how do you find the concentration of hydrogen ions of strong acids

the initial concentration of the acid is the same as the hydrogen ion because it dissociates completely

how do you find the concentration of hydrogen ions of weak acids

use the RICE equation with given initial concentrations and the Ka (always given) to calculate the equilibrium concentration of the ions

in the word pH, what does p stand for

-log of concentration of _______

pH is a log scale based on what

10

what is the pH formula

pH = -log[H+]

what is the pOH formula

pOH = -log[OH-]

what are the significant figures used for pH

the number of numeral places in concentration is the number of spaces after the decimal in the pH

since pH is on a scale of 10, it changes by how much for every power of 10 change in hydrogen ion concentration

1

which is more acidic and why, pH 3 or pH 4

pH3 because it has 10 times more hydrogen ions than pH

which is more acidic and why, pH 3 or pH 5

pH3 because it has 100 times more hydrogen ions than pH

if hydrogen ion concentration increases, what happens to the pH and why

pH decreases because it is a negalive log function

if hydrogen ion concentration decreases, what happens to the pH and why

pH increases because it is a negative log function

what is the correlation between pH and pOH

pH + pOH = 14

what is the correlation between [H+] and [OH-]

[H+] x [OH-] = 1 x 10^-14

what is the correlation between Ka and Kb of a conjugate base pair

Ka x Kb = 1 x 10^-14

monoprotic acid

acid that gives 1 hydrogen ion in water (ex : HCl)

diprotic acid

an acid that gives 2 hydrogen ions in water (ex : H2SO4)

polyprotic acid

an acid that gives three or more hydrogen ions in water (ex : H3PO4)

when do you need to find % dissociation

only when dealing with weak acids

how is dissociation % associated with dilution

% dissociation increases with diltuion

what are the strong bases

LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, Ba(OH)2

what is the trick to remebering the strong bases

they are the hydroxides forms with the metals in the first and second group of the periodic table

weak bases

many types of bases that do not contain OH; typically will have a lone pair of electrons

amine

a NH3-shapred compound with other groups replaceing the hydrogens

what is the general reation for bases

B + H2O --> BH+ + OH-

do polyprotic acids give all of their hydrogen ions in the same reaction

no

if polyprotic acids don't give all of their hydrogen ions in the same reaction, then they are released through several different reactions, what does this say about the Ka values for the reactions

the first Ka value is always the largest and then it decreases as the reactions go on to remove all of the hydrogen ions

can salts have acidic and basic properties

yes if the salt is paired with another one that it will react with

will the salt NaCl cause an acidic or basic solution

neutral

will the salt NaF cause an acidic o basic solution

basic

will the salt NH4Cl cause an acidic or basic solution

acidic

do the conjugate acids and conjugate bases of WEAK acids and bases react with water

yes

do the conjugate acids and conjugate bases of STRONG acids and bases react with water

no

is the solution acidic or basic if their is free-floating OH ions

basic

is the solution acidic ot basic if there is free-floating H ions

acidic

do salts dissociate in water

yes, they dissociate 100%

what is the formula for % dissociate

% diss = (used or created) / initial x 100

does the structure of a compound affect the acid base properties?

yes

what are the two main factors of a compounds structure that will affect the acid-base properties

strength of the bond and polarity of the bond

if the strength of a bond in a compound is stronger, is the compound more or less acidic

less acidic

if the strength of a bond in a compound is weaker, is the compound more or less acidic

less

if the polairty of a bond in a compound is more polar, is the compound more or less acidic

more

if the polarity of a bond in a compound is less polar, is the compound more or less acidic

less

electron density

the concentration of the electrons in a compound can affect the strength of the acid

if the electron density is far away from the acidic hydrogen, is the compound more or less acidic

more

if the electron density is close to the acidic hydrogen, is the compound more or less acidic

less

if the electronegativity of a compound is higher, is the compound more or less acidic

more

if the electronegativity of a compound is lower, is the compound more or less acidic

less

if a metal oxide and water combine, the result is a ____

base

if a non-metal oxide and water combine, the result is a _____

acid

Lewis acid

a molecule that accepts electrons

lewis base

a molecule that gives/donates electrons