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Acids, Bases, & Salts
I. Acids & bases
A. Properties
1. electrolytes -– will conduct electricity -- _______________
2. ________taste
___________ taste
3. turn litmus paper ____
turn litmus paper _____
4. react w/ _______ to form H2
_______react w/metals
5. “clean” feel
slippery feel
6. vinegar, _____, soda, apples…
ammonia, lye, antacid
citrus fruits, HCl
_______________, NaOH
7. pH ______
pH ______
8. produce _____ ions in water
produce _____ions in H2O
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II. Definitions
A. Arrhenius said:
1. An acid can be defined as a substance that yields _______________
(H+) when dissolved in water.
a. Hydrogen ions are aka hydronium ions & are also written as
_____
b. HCl when dry is _________________________
c. HCl when dissolved in water is hydrochloric acid …it breaks into
________________________________
2. A base can be defined as a substance that yields _____________
(OH-) when dissolved in water
B. Bronsted-Lowry said:
1. acids are proton (H+) _________________
2. bases are _____________ (H+) acceptors
3. Acids & bases come in pairs
a. conjugate base is the remainder of the original acid AFTER
it _______________its hydrogen ion
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b. conjugate acid is the particle formed when the original base
_______________ a hydrogen ion
4. Amphoteric – a substance that can act as both an acid & a base – like
_________________
C. Lewis (same guy who came up with the Lewis Dot structures) said:
1. acids are _________________________ acceptors
2. Bases are electron pair _____________.
Type
Arrhenius
BronstedLowry
Lewis
Acid
Base
H+ or H3O + producer
OH - producer
Proton (H +) donor
Proton (H +) acceptor
Electron-pair acceptor
Electron-pair donor
III. Common Acids & Bases
A. Acids
1. hydrochloric acid = _____________
used in “_____________” steel (removes rust, stains, impurities)
used to purify Mg from _____________________
found in ______________ to digest proteins
2. nitric acid = ___________
used in production of ___________________
used in production of ____________________
________________ easily – it’s volatile (must be stored
separately)
3. sulfuric acid =_______________
U.S. produces more of this than any other chemical!
used in production of________________
used in production of ____________________
used in petroleum _______________________
used in almost EVERY ___________________
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4. phosphoric acid = ___________
used in flavoring of ___________________
used in production of ______________________
used in production of _______________________
5. acetic acid = _________________
used in production of _____________________
used in making pharmaceuticals (meds)
vinegar!
B. Bases
1. examples: _______________ = lye= sodium hydroxide
_______________ = potassium hydroxide
_______________ = magnesium hydroxide
_______________ = lime water
IV. Acid Base Reactions
A. Neutralization Reaction – a reaction in which an acid & a base react in an
aqueous solution to ______________________ (ionic cmpd) & water
HCl (aq) + NaOH(aq)
NaCl(aq) + H2O(l)
1. Salts can be _______________, _________________, or
______________
2. Neutralization __________________ mean a pH of 7!
3. Every day uses:
a. ______________ depend on neutralization (MOM neutralizes
excess HCl in the stomach)
b. farmers us it to control _____________pH (some plants
require acidic soils like blueberries)
c. formation of ____________ stalactites
d. human body _________________ form from insoluble salts
e. wasp stings are basic so neutralize with _________________
or vinegar
f. red ant bites are ________________ so neutralize with
baking soda
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4. Neutralization reactions_______________ produce a salt & water!
B. Salt Hydrolysis – salt that reacts with _____________ to produce an
acid or a base
1. salt – an ____________ cmpd that comes from the anion (neg)of an
acid & the cation (pos) of a base & is formed from a neutralization
reaction
a. ____________ can be acidic, basic or neutral
2. Hydrolyzing salts come from
a. a _____________ acid & a weak base or
b. a ______________ acid & a strong base
Formulas and names of common salts
SALT
FORMULA
sodium chloride
(table) salt
NaNO3
sodium bicarbonate
Common Name
saltpeter
NaHCO3
potassium carbonate
potash
NH4Cl
sal ammoniac
V. Strength of Acids & Bases – classified by the degree to which they
________________ in water
A. Strong acids & bases _________________ ionize in water – that means
they completely separate into the +ions & the –ions
1. strong acids & bases are _________________ electrolytes
2. weak acids & bases are ________________electrolytes
B. Weak acids & bases ionize only _________________ in water
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C. Concentration
1. _____________________ & concentration are different things
2. concentrated or dilute tell us ______________ acid or base is
dissolved in the water
3. the words strong & weak for an acid or base refer to the extent of
_____________________ (separation into ions)
a. that means you can have a dilute strong acid!
D. ______- stands for the negative log of the H+ ion concentration…
1. Pure ___________ ionizes, or falls apart into ions:
H2O ↔ H1+ + OH1a. Called the “___________________________” of water
b. Occurs to a very small extent:
[H1+ ] = [OH1-] = 1 x 10-7 M
c. Since they are equal, a _________________ solution results
from water
2. All __________ produce the hydrogen ion (H+) when placed in water.
All ____________ produce the hydroxide ion (OH-) when placed
in water.
3. If something has a pH of 3 it means that the H+ ion concentration in
_____________________
4. Somebody (Sorensen) had a good idea to shorten it & make it a much
easier system for most to use.
5. pH 0 – 14
a. 7 is ____________ (equal number of H+ ions & OH- ions)
b. below 7 is ________________
c. above 7 is ________________
6. each step on the pH scale represents a factor of _____!
E. Why measure pH?
1. Solutions we use - everything from swimming pools, soil conditions for
_____________, medical diagnosis, soaps and shampoos, etc.
2. Sometimes we can use indicators, other times we might need a pH
meter
a. Indicators are compounds whose ____________ are sensitive
to pH – they change color based on pH
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F. _______________ is the process of adding a known amount of solution
of known concentration to determine the concentration of another
solution
1. Remember? - a balanced equation is a mole ratio
G. ____________ are solutions in which the pH remains relatively
_______________, even when small amounts of acid or base are added
1. made from a ______________________: a weak acid and one of
it’s salts; or a weak base and one of it’s salts
2. A buffer system is better able to _________________ in pH than
pure water
3. Since it is a pair of chemicals:
a. one chemical ___________________ any acid added
b. the other chemical would neutralize any additional base
c. AND, they produce each other in the process!!!
4. Buffers are useful!
a. They maintain the __________of human blood
b. In medicines they keep acidic meds from damaging our
___________________
calculations:
VI. pH “power of hydrogen”
A. Water naturally ________________into H3O+ & OH- making a very weak electrolyte
Ionization of water
2H2O
H3O+ + OHB. Pure water will self ionize to produce a molar concentration, M, of
[H3O+] = 1 x 10-7
&
[OH-] = 1 x 10-7
at 25oC (298K)
1. using this info they can get an ionization constant for water
Kw always = 1 x 10-14
Kw = [H3O+] x [OH-]
a. when one goes _______ the other goes _________ to reach equilibrium
(Le Châtliers principle)
b. If you know the Kw (which you do) & you know one of the concentrations then
you can calculate the other.
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C. Since the pH #’s are so small they found another way to express them – they
take the _____________
1. so pH= -log [H3O+]
2. pH ranges from 0 to 14
D. pOH deals with [OH-]-pOH = -log[OH-]
E. pH + pOH = 14
VII. Titration
A. equations
1. M1V1 = M2V2
2. Start with the ______________________ for the neutralization reaction.
3. Determine the ___________ of acid/base from the __________ solution used
during the titration.
4. Determine the _____________ of solution of the ________________ solution
used during the titration.
5. Determine the __________________ of the unknown solution.
In a titration, 27.4 mL of 0.0154M Ba(OH)2 is added to a 20mL sample of HCl solution of
unknown concentration. What is the molarity of the acid solution?