Acids and Bases Notes
Electrolytes
 Substances that, when __________ in water, produce aqueous solutions that will __________ electricity
 Strong electrolytes ______________ ___________ _____________
 Many _____________ compounds
 Weak electrolytes ________________ _____________ ______________
Solutions
 _________________ mixtures in which one substance is _______________ into another
 the “_______________” dissolves in the “_______________”
 example: Kool-Aid -water is the solvent, the drink mix is the solute
Molarity
 Molarity of a solution is equal to the number of ____________ ____ __________ divided by the number
of ___________ _____ _________________

 New symbol [square brackets]

[H+] = _______________ of H+ ions
 The larger the molarity, the more _________________ the solution
Concentrated
 In a concentrated solution, the amount of solute is __________ compared to the amount of solvent it is
____________ ______

Dilute
 In a dilute solution, there is much more _______________ than ______________
 Solutions are “____________” by adding more solvent
 ______________ is more dilute than ________________
 Acids and bases, as we use them in the lab, are usually ______________ ___________
 Ex: when we talk about “hydrochloric acid”, it is actually hydrogen chloride gas ____________ in water

 Concentrated acids have ______________ ______________
 Ex: “conc.” HCl = 12M; H2SO4= 18M
 In the lab, we usually use ______________ ______________
 Ex: 1.0M HCl, or 0.1M H2SO4
What is an acid?
 Many definitions are used
 ______________ ______________: a substance that produces ______________ in water
 Then,
 H3O+= ______________ ion
Properties of acids
 React with most metals to produce _______
 react with carbonates to produce ________
 taste _________
 damage living ______________

 ______________ bases
Common acids
 Acid formulas –start with H
 H3PO4
 HCl
 HC2H3O2
 H2SO4
 Also written CH3COOH
 HNO3
What is a base?
 Commonly called “______________”
 ______________ base:
 a substance that produces ______________ ions when added to water
Common bases
 There are three common varieties of bases:
1) ______________ compounds (OH-)
 ex: NaOH, Ba(OH)2
2) ______________ (CO32-) and ______________ (HCO3-)
 ex: Na2CO3, NaHCO3, CaCO3
3) ______________ (NH3) and ______________
Properties of bases
 React with fats and oils to produce ______
 damage living ______________
 feel ___________

 _____________ bitter
 ______________ acids
Hydroxide bases
 Release ______________ ______________ directly into the water

Carbonates and bicarbonates
 React with water to produce ______________ ions


Ammonia and amines
 React with water to produce ______________ ions

Chemical indicators: chemicals that change colors when in an acid or base solution
Phenolphthalein
 acids = ______________
 bases = ______________
Litmus
 acids = ______________
 bases = ______________
pH scale
 Used to indicate the ______________ or “______________” of a solution
 tells how strongly acidic a solution is…______________ how strong an acid is!
 Think pH as “______________”
 the lower the pH, the more _______, the _______ ______________ the solution
 The pH is the measurement of how many H+’s are in the water…NOT a measure of if the H+’s came
from a “strong” or “weak” acid!!!
pH scale
 0-2
 4 –6.99

 10 -12

 2 -4
 7


 12 -14
 7.01 -10


pH calculations
pOH calculations
The Big Five:
pH and pOH relationship
 In pure water at 25°C:
pH = -log [H+]
 [H+] =
[H+] = 10-pH
 [OH-] =
pOH = -log [OH-]
 Therefore,
 And ,
[OH-] = 10-pOH
pH + pOH = 14
Autoionization of water
 Water molecules can react with each other
H2O + H2O  H3O+ + OH At 25ºC,
 [H2O] is a constant
 Kw= [H3O+] [OH-] = 1x10-14
 Let’s use [H+] instead of [H3O+]
 Pure water is neutral
 [H+] =[OH-] = 1x10-7M
 If
,the solution is acidic
 If
,the solution is basic
Arrehnius neutralization
 Works for the reaction of a ______________ acid with a ______________ base
 Remember –acid (or base strength) has to do with how much of the acid (or base) ______________ in
water, not directly how many______________ _____are produced

What is an acid?
 Many definitions are used
 Arrhenius acid: a substance that ______________ ______________ in water
 Then, H2O + H+ H3O+
 H3O+ = hydronium ion
What is a base?
 Commonly called “______________”
 Arrhenius base:

a substance that ______________ ______________ ions when added to water
Arrehnius neutralization: Hydroxide base, general form

 what’s actually happening?

H+ + OH- H2O
 Salt = the ______________ from the acid ……+ the ______________ from the base
 Examples with a hydroxide base

NaOH+ HCl  NaCl + H2O

3H2SO4+ 2Al(OH)3Al2(SO4)3+ 6H2O
Arrehnius neutralization: carbonate base, general form

 what’s actually happening?
 2H++ CO32-H2CO3
 H2CO3 H2O + CO2
 Salt = the ______________ from the acid . . …+ the ______________ from the base
 Examples with a carbonate base
 CaCO3 + 2 HCl  CaCl2 + H2O + CO2
 H2SO4 + NaHCO3  Na2SO4 + H2O + CO2
Acid Strength
 Compare the difference in these two statements:
1) The more H+ ions in the water, the more ______________ the solution
2) The more H+ ions a compound produces, the ______________ the acid
 Strong acids release all of their H+ ions

 Strong acids are ______________ electrolytes
 Weak acids hold on to ______________ of their H+ ions

 Weak acids are ______________ electrolytes
 Weak acids reach ______________ with “______________” products
Don't get confused!
 A solution of a ______________ acid can be less acidic that a solution of a ______________ acid!
 IF: the strong acid solution is ______________ ______________ and the weak acid is ______________!