chapter 13: Acids and Bases Flashcards
what are some descriptions of an acid
- sour taste
- ability to dissolve metals
what are some descriptions of a base
- bitter taste
- slippery to the touch
what are some common acids?
- HCL (hydrochloric acid)
- H2SO4(sulfuric acid)
- HNO3(nitric acid)
- HC2H3O2 ( acetic acid)
- H3C6H5O7(citric acid)
what are some common bases?
NaOH (sodium hydroxide) KOH ( potassium hydroxide) Sodium Bicarbonate( NaHCO3) Sodium Carbonate(Na2CO3) Ammonia (NH3)
who developed the Arrhenius theory?
swedish chemist svante arrhenius
what was the Arrhenius theory?
acids are substances that increase the concentration of H+ when added to water
- bases increase concentration of OH- when dissolved in water
what is the neutralization reaction in the Arrhenius Acid-Base reaction
solution of acid and solution of base are mixed
what does the neutralization of an acid and metal hydroxide produce
H2O + OH (hydroxide and water)
what is an example of a neutralization reaction?
HCL(aq) + NaOH = H2O + NaCl
who developed the bronsted lowry theory?
danish chemist: bronsted
English chemist lowry
what was the Bronsted Lowry theory?
-acids are proton donors (Removeable H+)
-bases are proton acceptors
pair of nonbonding electrons
which acid-base theory do we use/ rely on
bronsted and lowry
what is an amphoteric substance
can act as either an acid or a base
what is a common example of a amphoteric substance
hydronium
what is the hydronium ion
H+ ions are so reactive that they can’t be in water
- small positive charged particles interacts with the nonbonding electron
what is an H+ ion
proton with no valence electron
what are some interchangeable terms
H+ and H3O+
which acid-base theory allows for reversible reactions
bronsted and lowry
how do bronsted and lowry reversible reactions work
- original base has an extra H+ after the reaction
- original acid has a lone pair (acts as base in reverse process)
what does conjugate mean
come together
what is a conjugate base
formed by removing a proton from acid
what is a conjugate acid
formed by adding a proton
what are some common strong bases
- sulfuric acid (H2SO4)
- hydrochloric acid (HCL)
- hydrobromic acid( HBr)
- Perchloric acid ( HCLO4)
- chloric acid (HCLO3)
- Nitric acid(HNO3)
what is monoprotic
acids with only one ionizable hydrogen
what is a polyprotuc acid
molecules with more than 1 ionizable hydrogen
what is the relationship between a strong polyprotic and the conjugate base
one polyprotic is strong and its amphoteric conjugate base is weak acid
organic acids contain what backbone
carbon that contains the carboxyl group
are organic acids weak or strong and why
weak because most of the H atoms are not ionizable
C-H
what is K used for in ionization
express the extent to which a weak acid ionizes
what is not included in the acid constant
liquids or solid
what does a greater K value indicate
the stronger acid
what factors can affect acid strength
- polarity and strength of the H-Y bond
- stability of the H-Y conjugate base
- bond strength
when will H transfer in a bond
if the H-Y bond is polarized
how does bond strength affect acid strength
strong bonds = easily dissociated (short bond length)
weak acids and bases = long bond length
how does the conjugate base affect acid strength
strong acid = more stable conj base (more stable = more strong)
stronger acid = weaker conj base
what is the strength of binary acids
more polar H-Y or weaker the bond = the more acidic compound
what is the trend for acidity
increases from left to right across a row and from top to bottom down a group
what is an oxyacid
OH groups and oxygen atoms are bound to a central atom
in an oxyacid group what happens when Y is a nonmetal
Y-O-H
- the bond to O is covalent = does not readily lose OH-
- electronegativity of Y increases = acidity of the substance
what is the rule of thumb for oxyacids that have the same number of O atoms and OH groups
acid strength increases with increasing EN of the central atom
oxyacids that have the same central atom
acid strength increases as the number of oxygen atoms attached to the central atom increases
what is the most important chemical property of water
it can act as either a bronsted lowry acid or base (ionization)
what is Kw
the ion product constant
at 25 degrees celsius what does Kw =
1.0 x 10-14
as [H3O]+ increases what happens to [OH]
OH has to decrease
what happens to H3O and OH in a neutral solution
they are equal to each toher
[H3O] =OH = 1.x10-7
acidic solutions have a larger H3O or OH
H3O
Basic solutions have a larger H3O or OH
OH
what is pH
acidity and bascity of a solutoin
how do do you calculate pH
-log (H3O)
how do you calculate H3O from pH
10^-pH
what is the pH of a neutral solution
7.00
lower pH means what
acidic solution
higher pH means that
more basic solution
what is the normal pH range
0-14
what is the rule of sig figs when calculating pH
number of decimal places in the log equals the # of sig figs in the O.G number
how do you find poH given oH
-log(OH)
how do you find POH from [oH]
10^-POH
what does POH + pH =
14
in an aqueous solution of a strong acid what is the source of H+ ions
the strong acid
what is H3O interchangable with
an acid
calculating the Ka for weak acids
when given the problem the weak acid is always mixed with water to produce another H3O + another aqueous solution that has one less H (use ice table)
how to calculate % ionization
[H3O]+eq/[Ha]initial x 100 = 10^-ph/[Ha}
why do we use percent ionization
since a weak acid ionizes partially we use it just to know how much has ionized
why do we sometimes exclude x from the ice table
because the ka is small
what happens when the concentration of an acid increases
strength increases and so does the pH
as the concentration of an acid increases, the percent ionization of the acid increases why
an acid is diluted by adding water to it which shifts the equilibrium to the left
what must the acid do to reach equilibrium
ionize more and shift to the right
most weak bases contain what
nitrogen because the lone pair on N makes it an excellent proton acceptor
what happens when a weak base interacts with water
produces a conjugate acid and OH ion
what is Kb
the base-dissociation constant
Kb can be used to find what directly
OH
greater value of Kb =
stronger the base
what is a polyprotic acid
acid and molecules with more than one ionizable H
polyprotic acids do what
ionize in steps
what does removing the first H automatically do to the second H
makes it harder to remove that is why the Ka value goes down
what do the Ka values for successive losses of protons differ by a factor of
10^3
what happens with ionization if the equlibrium lies to the righ
complete ionization
what does Kw equal
[H3O] + [OH] so Ka X Kb = 1.0x-14
pKa +pKb = p Kw = what
14.00
if you have a stronger acid what happens to the value of pKa
Larger Ka = smaller pKa because it is the -log
what is an oxide
molecule that contains the HOX group where X can be any element
If X is a nonmetal, in HOX
compound is a covalent oxide and when it is dissolved in water an acidic solution forms
what is an acidic oxide
when dissolved in water, an acidic solution forms
what happens if X is a metal
compound is an ionic oxide
who came up with the lewis theory
G.N lewis
what does the lewis theory say about acids
acids are electron pair acceptors and they must have an atom with an empty valence orbital
what does the lewis theory say about bases
bases are electron pair donors they must have lone pair electrons
anything that can be a bronsted lowry base
is a lewis base but not all lewis base are B-L bases
what is the arrhenius acid
substance produces H+ in water
what is the arrhenius base
substance produces OH in water
what is the bronsted lowry acid
proton donar
what is the bronsted base
proton accpetor
