Acid Base Notes

1. Ch. 20 Notes -- Acids and Bases
What makes something an acid?
Acid Properties:
sour lemons
(1) tastes _______-- _______________
metals
(2) corrosive to _________
H+ ] (or [ _____ ] = “_______________” ions)
(3) contains [ ___ H3O+ hydronium
H+ donor
(4) proton ([ ___ ]) __________-- Brønsted-Lowry Theory
H3O+
Cl− + ______
Example: HCl + H2O  ______

2. Examples of Common Acids:
• citrus aspirin
Pepsi, _________ juices, ___________, stomach acid, battery
vinegar DNA
acid, _____________, ______

3. Acid Vocabulary
• monoprotic acid- contains ____ [H+] ion in its formula
1
HCl HNO3
Examples: _______ , ________
• 2
diprotic acid- contains _____ [H+] ions in its formula
H2SO4 H2CO3
Examples: _______ , ________
• 3
triprotic acid- contains _____ [H+] ions in its formula
H3PO4 H3BO3
Examples: _______ , ________
• dissociate many
strong acid - readily ___________ to produce ______ [H+] ions in
water
HCl
Examples: _________, HNO , _______H2SO4
3
small
• weak acid - produces a __________ amount of [H+] ions when in
water
H2CO3 lemon juice
Examples: HC H O (vinegar) , _________, _________
2 3 2

4. Strong Acids vs. Weak Acids

5. Indicators
• An indicator is a chemical that will change ___________ when
colors
placed in an acidic, basic or neutral environment.
Indicator Colors For Acids
• red
litmus paper = _______
• clear
phenolphthalein = ___________
• red cabbage juice (universal indicator) = ________
red
• red
methyl orange = _______

6. pH Paper : Indicator Colors
Neutral
Acidic
Basic

7. Properties of Bases
What make something a base?
Base Properties: (…the opposite of acid properties)
bitter banana
(1) tastes ________ -- ___________ peel ,
parsley, dark chocolate
slippery soap
(2) feels _____________ -- ________
OH−
(3) contains [ _____ ] ions
acceptor
(4) proton ([H+]) ______________-- Brønsted-Lowry Theory
Example: NH + H O  ______ NH4+ + _______
OH−
3 2

8. Indicator Colors for Bases
• litmus paper = _______
blue
• yellow
methyl orange = ____________
• blue
red cabbage juice (universal indicator) =________
• phenolphthalein = ______
pink
phenolphthalein
Acid Base

9. Common Bases
• ammonia
Examples of Common Bases: milk of magnesia, ___________,
drain cleaner, soap, blood, ____________ tablets, ___________
antacid baking
soda
________.

10. Strong Bases vs. Weak Bases
• strong base- readily __________ to produce ______ [OH−] ions in
dissociate many
water
Examples: KOH
NaOH , ________
• small
weak base- produces a __________ amount of [OH−] ions when in
water
NH3
Examples: _____ (ammonia); Mg(OH) (milk of magnesia)
2
Other Vocabulary
• Alkaline
_______________- another term for basic solutions
Amphoteric
• _______________- a substance that can act as both an acid and a base
H2O HCO3−
Examples: ___________ , ____________

11. Conjugate Acid-Base Pairs
• Conjugate ______- substance formed when a _______ gains a
Acid base
[H+] ion.
• Base acid
Conjugate ______- substance formed when an ______ loses a
[H+] ion.
• Practice Problems: Label the acid & base on the left side of the
reaction and the conjugate acid & conjugate base on the right side.
a) HCl + H2O  H3O+ + Cl−
acid
______ base C.A. C.B.
______ ______ ______
b) NH3 + H2O  NH4+ + OH−
base
_____ acid C.A. C.B.
______ ______ ______

12. Self-Ionization of Water
• Pure water is _____________. It can ionize itself to form OH− and
neutral
H3O+ ions in __________ amounts.
small
H2O + H2O  H3O+ + OH−
H+
(or H2O  _______ + _______ OH− )
green
• The universal indicator color is ___________ in neutral solutions.
self-ionization of water

13. Measuring the Amount of H+ and OH− Ions in a Solution
• _____ Scale- measures the _____________ of [H+] ions in a solution
pH concentration
• pOH OH−
_____ Scale- measures the concentration of [ ____ ] ions in a solution
Formulas
pH = − (log [H+]) pOH = −(log [OH−])
[H+] = 10−pH [OH−] = 10−pOH
[H+] x [OH−] = 1 x 10−14 pH + pOH = 14
• With the pH scale, we have another way to define acids and bases:
below
Acids have a pH _________7.0
above
Bases have a pH _________7.0
=
Neutral pH ___7.0

17. Practice Problems:
1) a) Calculate the pH of a 0.001 M HCl solution
[H+] = 0.001 M So…pH = − (log 0.001 M) pH = 3
b) What is the pOH of this solution?
pH + pOH = 14 So…14 − 3 = pOH pOH = 11
c) What is the concentration of [OH−] ions in the solution?
[OH−] = 10−pOH [OH−] = 10−11 Molar or 1 x 10−11 M
2) a) Calculate the pOH of a NaOH solution that has a pH of 8.50
pH + pOH = 14 So…14 − 8.5 = pOH pOH = 5.5
b) What is the [OH−] of this solution?
[OH−] = 10−pOH [OH−] = 10−5.5 Molar or 3.16 x 10−6 M
c) What is the concentration of [H+] ions in the solution?
[H+] = 10−pH [H+] = 10−8.5 Molar or 3.16 x 10−9 M

18. Ch. 21 Notes -- Neutralization
Neutralization Reactions
• salt
When an acid and base are mixed, the reaction produces _______
water
and ___________.
• If the initial concentrations and volumes of the reactants are equal,
neutral
the products will be ____________... (pH= 7.0)
• double
All neutralization reactions are ___________ replacement
reactions.
HX + M(OH)  ______ + ______
MX H2O
(“Salt”)

19. Titration
• Mixing an acid with a base to
determine a __________________
concentration
is called “titration.”
• An ____________ is used to
indicator
determine when neutralization has
occurred.
• Standard
________________ Solution - the
solution of known concentration
• End Point
______ _________ - the point of
neutralization when titrating
• end
At the ______ point, the moles of
[H+] ions = moles of [OH−] ions.

20. Practice Problems:
(1) Complete the following neutralization reactions.
HNO3 (aq) + KNO3 H2O
KOH (aq)  _________ + __________
2 HCl CaCl2
+2 −1
2H2O
(aq) + Ca(OH)2 (aq)  __________ + ___________
(2) How many moles of Ca(OH)2 will it take to neutralize 0.5 moles of
HCl?
0.5 moles HCl x 1 mole Ca(OH)2 = 0.25 moles of Ca(OH)2
2 moles HCl
3) How many moles of HNO3 will it take to neutralize 3.0 moles of
KOH?
3.0 moles KOH x 1 mole HNO3 = 3.0 moles of HNO3
1 mole KOH

21. Determining the Concentration of an Acid (or Base) by Titration
(Macid)x(Vacid) = (Mbase)x(Vbase)
Practice Problems:
• A 25 mL solution of HNO3 is neutralized by 18 mL of 1.0 M
NaOH standard solution using phenolphthalein as an indicator.
What is the concentration of the HNO3 solution?
( Macid ) x ( 25 mL ) = ( 1.0 M ) x (18 mL )
Macid = 0.72 Molar
(2) How many mL of 2.0 M KOH will it take to neutralize 55 mL of
a 0.76 M HCl standard solution?
(0.76 M ) x ( 55 mL ) = ( 2.0 M ) x ( Vbase )
Vbase = 20.9 mL