Acid Base Intro notes 2012
Acids: start with “H” (make H+ ions) like: HCl,
H2SO4, HF,
H3PO4
Taste sour, have a pH less than 7
(Practice nomenclature of some acids)
Bases: end with “OH” (make OH- ions) like: LiOH, NaOH,
KOH, Al(OH)3
Taste bitter, feel slippery (dissolve fats)have a pH greater than 7
(Practice nomenclature of bases)
Some acids are di-protic or tri protic and have a double or
triple normalicy.
Some bases are di or tri hydroxyl and have a double or triple
normalicy.
Ammonia is another type of base called a Lowry/Bronsted base
NH3 + H2O  NH4+ + OH-
There are 3 standard definitions of an ACID:
Arrhenius: start with “H” and produce H+ ions in water
Lowry-Bronsted: are a proton donor
Lewis: electron pair acceptor
There are 3 standard definitions of a Base:
Arrhenius: end with “OH” and produce OH- (hydroxide) ions in
water
Lowry-Bronsted: are a proton acceptors
Lewis: electron pair donor
The concentration of the Hydrogen ion (H+) or more precisely the
hydronium ion (H3O+); since in water there are always so many
water molecules for the hydrogen ion to connect with. The
concentration of H+ is so critical in the rate of chemical reactions
(and the equilibrium of the human body) that we have a special
scale for measuring tiny concentrations of the H+ ion called the pH
scale.
pH means power of the hydrogen ion concentration
Mathematically pH is a function defined as:
pH = - log [H+]
(pH is the negative of the log of the hydrogen ion concentration)
remember
1x10-1 = .1
1x10-7 = .0000001
1x10-14 = .00000000000001
(Do worksheet on pH, pOH and hydronium ion concentration)
Acids and Bases NEUTRALIZE to produce salts and water
Acid + Base  salt + water
(not just table salt, any salt)
More acid/base notes (and some review)
Acids:
Dissolve metals, (producing H2 gas)
react with carbonates to produce bubbles,
low (1-7) pH,
Must have hydrogen (often have oxygen as well),
turns Litmus paper RED,
taste SOUR
When they ionize they produce H+ ions which combine with water
to make the H3O+ (hydronium ion)
Bases:
High pH (over 7),
good for cleaning (like ammonia),
turn litmus paper BLUE,
taste bitter
feel slippery
Bases ionize to produce OH- (hydroxide ions)
Indicators: are a class of chemicals that undergo a visible
color change in chemical environments that have a greater
abundance of H+ or OH- ions.
Three indicators that you need to be aware of are:
Bromthymol Blue:
Blue in bases
yellow in acids
Phenolphthalein
violet in bases
clear in neutral or acid
Universal indicator (a mixture of four separate indicators that
include, bromthymol blue, phenolphthalein, and methyl red)
ROY G BIV
ROY G BIV
(know the colors this reminds us of)
The colors of visible light (in a rainbow)
lowest energy or longest wavelength() to highest energy or shortest wavelength()
Another important one is Anthocyanin (we will just call it
cabbage juice indicator)
We can extract anthocyanin from red cabbage leaves in a variety
of manners
CRUSHING, BOILING AND CHOPPING
Cabbage juice indicator is _____blue/lavender__ in water (neutral)
Cabbage juice indicator is ____reddish pink________ in acids
Cabbage juice indicator is _____green__________ in bases
Some acids are poly-protic (means they can give up more than one hydrogen ion)
HNO3 is monoprotic, H2SO4 is diprotic, H3PO4 is triprotic
Strong acids completely ionize (change from molecules to ions)
Have large Ka
Strong Bases completely dissociate (dissolve from their formula
unit to their ions)
Have large Kb
weak ones (acids and bases) will try to remain together and will
covert from their equilibrium positions as stress is placed upon
them
(water is just as weak an acid as it is a weak base)
Acids are formed from reaction of non-metal oxides and water
Ex: SO2 + H2O  H2SO4
Bases are formed from metal oxides and water
Ex: CaO + H2O  Ca(OH)2
(Memorize these strong acids: HCl, HBr, HI,H2SO4, HNO3,
HClO3(Chloric acid)HClO4(Perchloric acid))
and HC2H3O2 or CH3COOH as acetic (or ethanoic acid aka
vinegar) a very common weak acid
(Memorize these strong bases: LiOH, NaOH, KOH, RbOH,
CsOH, FrOH, Ca(OH)2, Sr(OH)2, Ba(OH)2, Ra(OH)2) the alkali
metals and the soluble alkaline earth metals.
And the base NH3 (ammonia) an important weaker base helps you
understand Lowry-Bronsted conjugate pairs.
NH3 + H2O  NH4+ and OH(NH3 and OH- are the bases; H2O and NH4+ are the acids)
Neutralization occurs when the same number of Moles of acid
reacts with an equivalent number of moles of base to
stoichiometerically form a salt and water.
The equation to remember is:
mLacid Macid = mLbase Mbase
(volume times concentration = volume times concentration)
Volume measured in milliliters and concentration measured in
Molality (moles per liter)
A salt may hydrolyze (react with water) to form an acidic or alkali
solution, depending upon its “parent” acid and base.
A parent acid and a parent base neutralize to for a salt that may be
“acidic” like it’s parent acid ; basic (or alkali) like it’s parent base
or neutral, equally acidic and alkali (more common)