Chapter 8 Acids and Bases Chemistry B11. Acids and Bases Acids: sour Bases: bitter or salty.
What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable...
Transcript of What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable...
![Page 1: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/1.jpg)
![Page 2: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/2.jpg)
What are Acids and Bases?
What are some common acids you
know?
What are some common bases you
know?
Where is it common to hear about pH
balanced materials?
![Page 3: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/3.jpg)
Historically, classified by their observable
properties
› Acids:
Have a sour taste – like lemons or sour candy
Corrode metals – learned not to store vinegar
or fruit juices in metal containers
Changed blue litmus dye to red
› Bases:
Bitter in taste
Slippery in feel
Changed red litmus dye to blue
![Page 4: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/4.jpg)
![Page 5: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/5.jpg)
1. Arrhenius Definition:
› Experimented with electrolytes
› Aqueous solutions of acids and bases
conduct electricity
› Therefore, the compounds were forming
positive and negative ions in solution
![Page 6: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/6.jpg)
Arrhenius Model of Acids
An aqueous solution that produced hydrogen
ions, H+
Example: HCl (g) H+ (aq) + Cl- (aq)
Arrhenius Model of Bases
An aqueous solution that produced hydroxide
ions, OH-
Example: NaOH (s) Na+ (aq) + OH- (aq)
![Page 7: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/7.jpg)
The Arrhenius model explains how acids
and bases neutralize each other
› H+ (aq) + OH- (aq) H2O (l)
He did earn the 1903 Nobel Prize in
Chemistry
› Insisting that the H+ (aq) and OH- (aq) were
important in acid and base behavior
![Page 8: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/8.jpg)
Fundamental Problems:
› H+ ion: essentially a proton with a small radius & positive charge
› Therefore, H+ are unlikely to exist as free ions
in aqueous solutions
› Instead they exist with surrounding water
molecules resulting in: Hydronium ion, H3O+
(aq) as we know them today
![Page 9: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/9.jpg)
![Page 10: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/10.jpg)
Fundamental Problems:
› Assumes that all bases contain OH- ions
› Many ionic compounds (salts) have basic
properties such as the ability to neutralize acids
› Examples: metal oxides, carbonates,
fluorides, ammonia (NH3)
![Page 11: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/11.jpg)
Binary Acids – contain hydrogen and
one other element
Use: hydro_______ic acid
› Ex: HCl = hydrochloric acid
› Ex: H2S = hydrosulfuric acid
![Page 12: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/12.jpg)
Oxyacids – contain hydrogen and a poly atomic ion › Use ending of ion for naming:
-ite -ous acid “I bite a delicous apple”
-ate -ic acid “I ate something icky”
› Ex: HNO3 = nitric acid
› Ex: HNO2 = nitrous acid
› Ex: HC2H3O2 = acetic acid
› Ex: H3PO3 = phosphorous acid
![Page 13: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/13.jpg)
Strong Acid or Base:
› A strong electrolyte and completely ionizes
or dissociates in water
Weak Acid or Base:
› A weak electrolyte and only partially ionizes
in water
![Page 14: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/14.jpg)
![Page 15: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/15.jpg)
Examples:
›HCl – hydrochloric acid: stomach
acid, pools
›HBr – hydrobromic acid
›H2SO4 – sulfuric acid: car battery
acid, acid rain
![Page 16: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/16.jpg)
Strong Bases: completely ionize in water
Most of the common strong bases are
the ionic hydroxides from group 1 and 2
metals.
Dissociate completely win water to form
OH- and the cation it was bonded to
![Page 17: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/17.jpg)
Example: H2O
NaOH (s) Na+ (aq) + OH- (aq)
![Page 18: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/18.jpg)
Examples:
›NaOH – sodium hydroxide: drain
cleaners
› KOH – potassium hydroxide
›Mg(OH)2 – magnesium hydroxide:
used in antacids
![Page 19: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/19.jpg)
Examples:
›Acetic Acid (CH3CO2H) –
vinegar, sour wine
›Carbonic acid (H2CO3) – soda,
blood
›Citric acid (H3C6H5O7) – fruit,
soda
![Page 20: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/20.jpg)
Examples:
›Ammonia (NH3) – glass cleaners
›Calcium carbonate (CaCO3) – antacids, minerals
›Calcium hypochlorite (Ca(OCl)2) – chlorine source for swimming pools
![Page 21: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/21.jpg)
Brǿnsted-Lowry Acid:
› Any substance that can donate an H+ ion to
another substance
Brǿnsted-Lowry Base:
› Any substance that can accept an H+ ion
from another substance
![Page 22: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/22.jpg)
Polyprotic Acid:
› An acid containing more then one acidic hydrogen
› Examples: Phosphoric acid: H3PO4 – 3 acidic
hydrogens
Carbonic acid: H2CO3 – 2 acidic hydrogens
Sulfuric acid: H2SO4 – 2 acidic hydrogens
![Page 23: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/23.jpg)
Polyprotic acids do not lose all their
acidic hydrogen atoms in water to
the same extent
Example: Sulfuric Acid complete ionization….
H2SO4 (aq) + H2O (l) H3O+ (aq) + HSO4
- (aq)
Once HSO4- (aq) forms, it also acts as an acid, but as a weak
acid:
HSO4- (aq) + H2O (l) H3O
+ (aq) + SO42- (aq)
![Page 24: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/24.jpg)
Lewis Acid: substance that is an
electron–pair acceptor
› To avoid bonding based on hydrogen
› BF3 (aq) + F- (aq) BF4- (aq)
Lewis Base: substance that is an
electron-pair donor
![Page 25: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/25.jpg)
Acid Base
Arrhenius H+ donor OH- donor
Bronsted-Lowry
p+ donor p+ acceptor
Lewis e- pair acceptor e- pair donor
![Page 26: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/26.jpg)
Conjugate Acid:
› The product that forms as a result of gaining
an p+
Conjugate Base:
› The product that forms as a result of losing
an p+
Example:
HCl (g) + H2O (l) H3O+ (aq) + Cl- (aq)
acid base conjugate acid conjugate
base
![Page 27: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/27.jpg)
![Page 28: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/28.jpg)
Conjugate acid-base pairs always differ
by one H+ ion
› Conjugate acids has one more H+
Has one more H atom in its formula
Increase in charge by 1
› Conjugate base has one less H+
Has one less H atom in its formula
Decrease in charge of 1
![Page 29: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/29.jpg)
Amphoteric Substances:
› A substance that can act as either an acid
or a base
› Examples:
Water (most common)
Acid: donates H+ forming OH-
Base: accepts H+ forming H3O+
![Page 30: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/30.jpg)
![Page 31: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/31.jpg)
![Page 32: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/32.jpg)
Examples › Bicarbonate ion, HCO3
-
Found in sodium bicarbonate, used to neutralize both acids and bases
› When mixed with a basic solution, it acts as an acid
HCO3- (aq) + OH- (aq) CO3
2- (aq) + H2O (l) acid conjugate base
› When mixed with an acidic solution, it acts as a base
HCO3- (aq) + H3O
+ (aq) H2CO3 (aq) + H2O (l) base conjugate acid
![Page 33: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/33.jpg)
Strong acids completely dissociate to form H3O
+ and strong bases completely dissociate to form OH-
HCl (aq) + NaOH (aq) NaCl (aq) + H2O (l)
Neutralization reactions: a reaction where hyronium ions and hydroxide ions form water molecules
Salt: ionic compound composed of a cation from a base and an anion from an acid
![Page 34: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/34.jpg)
![Page 35: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/35.jpg)
Self-Ionization of Water
› Two water molecules interact to produce a
hydronium ion and a hydroxide ion by
proton transfer
2 H2O H3O+ (aq) + OH- (aq)
› At 25oC, 1 mole of hydronium and hydroxide
ions exist in 107 liters of water
› Therefore: 1 mole ions = 1 x 10-7 M
107 L water
![Page 36: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/36.jpg)
Water is neutral when the [H3O+] = [OH-]
Water dissociation constant (Kw) – constant rate at which water dissociates › Different at each temperature
Kw = [H3O+][OH-]
= [1 x 10-7 M][1 x 10-7 M]
= 1 x 10-14 M2
![Page 37: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/37.jpg)
pH: The negative logarithm (base 10) of
the [H3O+]
› Equation: pH = - log [H3O+]
› Example: pure water
pH = - log [H3O+]
pH = - log (1.0 x 10-7)
pH = 7
Pure water has [H3O+] = [OH-] => pH = 7
![Page 38: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/38.jpg)
Acidic solutions have pH < 7
Basic solutions have pH > 7
![Page 39: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/39.jpg)
The pH and pOH total is equal to 14.00
pH + pOH = 14.00
This relationship allows us to determine the pH if the pOH is known
pH = 14.00 – pOH = 14.00 – 2.00
= 12.00
![Page 40: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/40.jpg)
Some common
substances, their
pH and their
[H3O+]
French: “pouvior
hyrogene,”
meaning
“hydrogen
power”
![Page 41: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/41.jpg)
Consider the pH values of
solutions that range in [H3O+] from
1.0x10-1 M to 1.0x10-14
M
Notice that the pH value = the
exponent in the [H3O+] but with a
positive value
› Only allows for calculation if the
[H3O+] is a power of ten
![Page 42: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/42.jpg)
Example: What is the pH of each of the
following solutions? Once calculated,
check to make sure you answer makes
sense.
› A) 0.0010 M HBr
› B) 0.035 M HNO3
› C) 0.035 M KOH
![Page 43: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/43.jpg)
Answer: A) 0.0010 M HBr
› HBr is a strong acid, which ionizes
completely, so [H3O+] = [HBr]
› pH = - log [H3O+]
› pH = - log (0.0010)
› pH = 3.00
› Acid!
![Page 44: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/44.jpg)
Answer: B) 0.035 M HNO3
› Nitric acid is also a strong acid, so the [H3O+]
= [HNO3]
› pH = - log [H3O+]
› pH = - log (0.035)
› pH = 1.46
› Acid!
![Page 45: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/45.jpg)
Answer: C) 0.035 M KOH
› Potassium hydroxide is a strong base, which
dissociates completely to form K+ (aq) and
OH- (aq)
› The [KOH] = [OH-] = 0.035 M
› In order to calculate pH, we need [H3O+]
› [H3O+] = Kw_ = 1.0 x 10-14 = 2.9 x 10-14 M
[OH-] 0.0035 M
![Page 46: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/46.jpg)
Answer: C) 0.035 M KOH
› [H3O+] = 2.9 x 10-14 M
› pH = - log [H3O+]
› pH = - log (2.9 x 10-14 )
› pH = 12.54
› Base!
![Page 47: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/47.jpg)
If you can calculate the pH from your
[H3O+], can you do the reverse? Yes!
How? Rearrange your parent equation!
pH = - log [H3O+]
-pH = log [H3O+]
Inverse log (-pH) = [H3O+]
10-pH = [H3O+]
![Page 48: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/48.jpg)
Example: Olivia measures the pH of a
soil sample solution to have a pH = 6.20,
what is the [H3O+] ?
![Page 49: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/49.jpg)
Answer:
› [H3O+] = 10-pH
› [H3O+] = 10-6.20
› [H3O+] = 6.3 x 10-7 M
![Page 50: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/50.jpg)
If you can calculate the pOH from your
[OH-], can you do the reverse? Yes!
How? Rearrange your parent equation!
pOH = - log [OH-]
-pOH = log [OH-]
Inverse log (-pOH) = [OH-]
10-pOH = [OH-]
![Page 51: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/51.jpg)
Example: Jake measured the pH of water in a swimming pool as 8.10. What is the OH-
concentration in the pool water?
![Page 52: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/52.jpg)
Answer:
Determine the pOH from the pH
pH + pOH = 14.00
8.10 + pOH = 14.00
pOH = 5.90
![Page 53: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/53.jpg)
Answer:
pOH = 5.90
Then calculate the [OH-]
› [OH-] = 10-pOH
› [OH-] = 10-5.90
› [OH-] = 1.3 x 10-6 M
![Page 54: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/54.jpg)
Several Methods:
1. pH Meter:
Very accurate to within hundredths of a pH unit
Measures the voltage that develops when electrodes are dipped into the solution
![Page 55: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/55.jpg)
![Page 56: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/56.jpg)
![Page 57: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/57.jpg)
2. pH Indicators or Litmus Strips:
Less accurate but more convenient and cost friendly
Brightly colored organic dyes that are weak acids or bases › In solution they form an equilibrium with their
conjugate bases
› Color of the indicator depends on whether the dye is in its acidic or basic form
![Page 58: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/58.jpg)
2. pH Indicators or Litmus Strips:
Ex) Phenolphthalein
HIn (aq) + H2O (l) H3O+ (aq) + In- (aq)
colorless pink
In the acidic form: HIn (aq) = colorless
In the basic form: In- (aq) = pink
Changes from colorless to pink between
pH 8.2 and 10
![Page 59: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/59.jpg)
![Page 60: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/60.jpg)
An indicator reveals if the pH of a
solution is above or below a certain
value
Also disclose a specific pH within the
indicators color-change range
Subtle differences in hues are discernible
at slightly different pH values
![Page 61: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/61.jpg)
A mixture of indicators having a variety of colors and color-change ranges can be used to measure the pH of any solution
Broad-range pH paper is treated with several indicators › The user reads the pH by comparing the
color the paper turns to a chart of reference colors and pH values
![Page 62: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/62.jpg)
![Page 63: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/63.jpg)
The formation of water is quite common
from the addition of hydrogen ion (H+)
and the hydroxide ion (OH-)
![Page 64: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/64.jpg)
![Page 65: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/65.jpg)
Titration: › The process of determining the
concentration of one substance in a solution by reacting it with a solution of another substance that has a known concentration.
› Add the known substance until the reaction between the two substances is complete: equivalence point
› Shown by an indicator: changes color due to sensitivities of acids and bases
› End point: the point at which the indicator changes color
![Page 66: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/66.jpg)
![Page 67: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/67.jpg)
![Page 68: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/68.jpg)
![Page 69: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/69.jpg)
Phenolphthalein
![Page 70: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/70.jpg)
Molarity = moles / Liter
Macid x Vacid = Mbase x Vbase
**Only true for a 1 to 1 mole
ratio between the acid and
base
![Page 71: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/71.jpg)
Normality (N) – number of equivalents of
solute per liter of solution
Equation: N = n * M
normality = number of equiv * Molarity
What is the molarity of a 0.090 N Ca(OH)2
soln?
› N = n * M
› 0.090 N = 2 equiv * M
› M = 0.045 M Ca(OH)2
![Page 72: What are Acids and Bases? 1415H Notes.pdf · Historically, classified by their observable properties ›Acids: Have a sour taste – like lemons or sour candy Corrode metals – learned](https://reader034.fdocuments.us/reader034/viewer/2022043007/5f934bd10f2e6d615d153abb/html5/thumbnails/72.jpg)
Chapter 14 p. 491-493
› #15, 23, 24
Chapter 15 p. 523-525
› #6, 9, 12, 15, 26, 31, 36