ACIDS AND BASES
NAME ________________________________________
Properties of Acids
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Produce _________ (as H3O+) ions in water (the hydronium ion is a hydrogen ion attached to a water molecule)
Taste ______________
Corrode ___________
Electrolytes
React with ________
pH is ___________ than 7
Acids react with certain metals to produce ________________gas.
Mg + HCl →
Common Acids:
Properties of Bases
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Produce _______________ ions in water
Taste _____________, chalky
Are electrolytes
Feel soapy, slippery
React with __________
pH _____________ than 7
Some Common Bases:
Indicators
Indicators tell if a substance is an acid or a base by the ___________________of the indicator.
Litmus paper: Blue to red---- _____________ Red to blue--- __________________________
Phenolphthalein : Acid--- ___________________ Base--- ____________________
Acid/Base definitions
Definition #1: Arrhenius
Acids –
Bases –
Definition #2: Brønsted – Lowry
Acids –
Bases –
A “proton” is really just a hydrogen atom that has __________________the electron
Label the acid and base in the following:
1. HClO4 + OH- → ClO4- + H2O
2. NO3- + H2O → HNO3 + OH3. F- + H2O → HF + OHAmphiprotic (amphoteric)Examples:
Naming Acids
Binary Acids (H + 1 element)
HCl _____________________________
HF ________________________________
HBr ______________________________
HI _________________________________
OXY ACIDS: Hydrogen + Polyatomic Ion
HNO3 ______________________________
H2SO4 ______________________________
HClO4 _____________________________
HC2H3O2 _____________________________
Conjugate Acid and Base
Conjugate Acid- substance formed when a base _____________________ a proton (H+)
Conjugate Base- substance that remains when an acid _________________________ a proton (H+)
Label the acid, base, conjugate acid and conjugate base.
HClO4 + H2O → ClO4- + H3O+
HNO3 + H2O → NO3- + H3O+
HCO3- + HSO4- → H2CO3 + SO4-2
Practice: Give the conjugate base of:
HNO3 ______________
H2SO4 ______________ HSO4- _________________
Give the conjugate acid of:
H2O ________________ ClO3- ________________ HPO4-2 ________________
Strong and Weak Acids/Bases
The strength of an acid (or base) is determined by the amount of ____________________________________.
Strong acids dissociate (ionize) ________________________
HCl, HBr, HI, HNO3 H2SO4 and HClO4 are among the only known strong acids.
Strong acids have a _____________________ concentration of H+ ions
Weak acids are much less than 100% ionized in water. ____________________ ionize.
One of the best known is acetic acid = ______________________
_______________________ concentration of H+ than strong acids
__________________________pH than strong acids.
Which of the following has the highest pH?
A) 0.10 M HCl
B) 0.10 M HC2H3O2
C) 0.10 M HNO3
Strong Bases
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Ionize _________________________
_______________ pH
The strong bases are group 1 hydroxides and Ca, Sr, and Ba hydroxide
NaOH → Na+ + OH-
Weak Bases
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________________________ ionize
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_____________________ pH than strong bases
Common weak base is ammonia (NH3)
Arrange the following from lowest to highest pH
NH3, HCl, NaOH, H2O, HC2H3O2 __________________________________________________________________
H2O can function as both an ACID and a BASE. In pure water there can be AUTOIONIZATION.
H2O → H+ + OH[H+] [OH-] = 1.00 x 10-14
In an _______________ solution [H+] > [OH-]
In a ______________ solution [OH-] > [H+]
In a ____________________solution [H+] = [OH-]
Example: A solution has a [H+] = 2.5 x10-3 M. What is the [OH-]?
The pH scale is a way of expressing the strength of acids and bases.
Under 7 = ____________
Calculating the pH
Example: If [H+] = 1 X 10-10
7 = ______________
pH = - log [H+]
Over 7 = ____________________
(Remember that the [ ] represent Molarity)
Example: If [H+] = 1.8 X 10-5
Practice
Find the pH:
1) [H+]= 0.15 M
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2) [H+] = 3.00 X 10-7 M _________________
pH calculations – Solving for H+
If the pH of Coke is 3.12, [H+] = ???
Because pH = - log [H+] then
- pH = log [H+]
Take inverse log (10x) of both sides and get
10-pH = [H+]
[H+] = ____________________
*** to find antilog on your calculator, look for “Shift” or “2nd function” and then the log button
EX) A solution has a pH of 8.5. What is the Molarity of hydrogen ions in the solution?
pOH
pOH = - log [OH-]
On the pOH scale:
Below 7 = __________
Above 7 = ____________ At 7 = ____________
pH + pOH = 14
Practice
1. [OH-] =3.2 x 10-3 M. pOH =?
4. pOH = 13.6
[OH-] = ?
2. [OH-] =2.1 x 10-9 M. pH =?
4. pOH = 4.77 [H+] =?
pH of Strong Acids
1. What is the pH of 0.10 M HCl?
2. What is the pH of 0.025 M HNO3?
pH of Strong Bases
1. What is the pH of a 0.10 M solution of NaOH?
2. What is the pH of 0.10 M Ca(OH)2? (Honors)
Neutralization Reactions
Type of double replacement reaction.
Acid + Base → Salt + Water
A salt is an ______________ compound
HC2H3O2 + NaOH →
H2SO4 + KOH →
HCl + NaOH →
HNO3 + Ba(OH)2 →
Titration
________________________ analysis used to determine the ___________________ (molarity) of an acid or base
Endpoint: __________________________
Equivalence point: moles of ____________ = moles of __________________
nMAVA = nMBVB
n = # H atoms in acid
MA = molarity of acid
VA = volume of acid
Monoprotic acid- acid with one H+ (HCl)
n = # OH in base
MB = molarity of base
VB = volume of base
Polyprotic acid- more than one H+ (H2SO4)
Examples
Calculate the molarity of HCl if 25.00 ml of HCl were needed to neutralize 38.28 ml of 0.4370 M NaOH.
Calculate the molarity of NaOH if a 50.00 ml sample neutralizes 24.09 ml of 1.605 M H2SO4.
Buffers
Resist changes in pH when __________________ amounts of acid or base are added
Ex: