1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an...
-
Upload
cory-jennings -
Category
Documents
-
view
216 -
download
1
Transcript of 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an...
![Page 1: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/1.jpg)
1
- SCH3U1 -Acids and Bases
Sections 10.1
![Page 2: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/2.jpg)
2
Learning Goals
1. What is Arrhenius's definition of an acid? A base?
2. What is the Brønsted-Lowry definition of an acid? A base?
3. What do the terms "strong" and "weak" mean when applied to an acid or a base?
4. How are common acids and bases named?
5. How is an acidic anhydride formed? A basic anhydride?
![Page 3: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/3.jpg)
3
Acids General Properties• Acids are substances that exhibit the following
properties when dissolved in water: – Acids taste sour. (Do NOT taste chemicals!)– Acids produce a stinging sensation on the skin
when they enter an open wound. – Acids turn the color of the indicator dye litmus
from blue to red. – Acids react with many metals, such as magnesium,
zinc, and iron, to produce ionic compounds and hydrogen gas.
– Acids react with bases, thereby losing their acidic properties.
![Page 4: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/4.jpg)
Table 10.1 Common Acids
4
![Page 5: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/5.jpg)
5
Bases General Properties
• Bases exhibit the following properties when dissolved in water:
– Bases taste bitter. (Do NOT taste chemicals!)
– Bases feel slippery or soapy on the skin.
– Bases turn the color of the indicator dye litmus from red (pink) to blue.
– Bases react with acids, thereby losing their basic properties.
![Page 6: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/6.jpg)
6
Table 10.1 Common Bases
![Page 7: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/7.jpg)
Conductivity of Strong Acids & Bases?
7
![Page 8: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/8.jpg)
HCl = Strong Acid
8
![Page 9: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/9.jpg)
Acetic Acid = Weak Acid
9
![Page 10: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/10.jpg)
NaOH = Strong Base
10
![Page 11: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/11.jpg)
Ammonia = Weak Base
11
![Page 12: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/12.jpg)
Properties of Acids and Bases
• Taste
• Conductivity
• Feel
• Reaction with litmus paper
• Reaction with active metals
• Reaction with carbonate compounds
12
![Page 13: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/13.jpg)
Properties of Acids and Bases
13
![Page 14: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/14.jpg)
14
![Page 15: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/15.jpg)
Arrhenius Theory
15
![Page 16: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/16.jpg)
Arrhenius Theory
How would the following acids dissociate in water according to Arrhenius?
What is the recognizable PATTERN?
HBr (aq) HClO4 (aq)
LiOH (aq) Ba(OH)2 (aq)
16
![Page 17: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/17.jpg)
17
Arrhenius Theory
• In 1887 the Swedish chemist Svante Arrhenius proposed:
– An acid is a substance that ionizes (breaks up into ions) in water to produce 1 or more H+ ions
– A base is a substance that dissociates in water to form 1 or more OH- ions
![Page 18: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/18.jpg)
Let’s Use Arrhenius here…
• According to Arrhenius you have to have and H+ and an OH- in the base of an acid or base that is being dissociated to create an H+ or OH- in the products.
• This is not true!
• NH3 (aq) + H2O (l) NH4+ (aq) + OH- (aq)
18
Limitations to Arrhenius Theory?
We know NH3 is a base!
![Page 19: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/19.jpg)
19
Limitations of Arrhenius Theory
• A free proton does not exist in water solutions. Polarity of water?
Hydronium Ion H3O+ – a hydrated proton,
H
H
O:
:
+ H+ H
H
O
:
H+
WaterHydrogen Ion
(proton) Hydronium Ion
![Page 20: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/20.jpg)
20
Brønsted-Lowry Theory
These shortcomings were overcome by a theory proposed independently, in 1923, by J. N. Brønsted (Denmark) and T. M. Lowry (London)
An acid is a proton donor A substance that gives up H+ (a proton).
A base is a proton acceptorA substance that accepts H+ (a proton).
TRANSFER OF A PROTON!!!
![Page 21: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/21.jpg)
21
Brønsted-Lowry Examples
Hydrogen Chloride in water is Hydrochloric acid
![Page 22: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/22.jpg)
22
Brønsted-Lowry Examples
Ammonia in water is a base
![Page 23: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/23.jpg)
Conjugate Acid-Base PairsBy Brønsted-Lowry theory, the products of an
acid base reaction are also acids and bases.
An acid-base conjugate pair differs in structure only by a proton (H+):
CONJUGATE means “linked together”
• The conjugate acid of a species is that species plus a proton;
• The conjugate base of a species is that species minus a proton.
CH3COOH + H2O H3O+ + CH3COO-
acidacid basebase conjugateconjugateconjugateconjugate
acid base acid base
![Page 24: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/24.jpg)
24
Brønsted-Lowry Notes
Like Arrhenius a Brønsted-Lowry acid must have a H+.*So all Arrhenius acids are also Brønsted-Lowry acids
However, any negative anion species can be a Brønsted-Lowry base. (not only OH-)
![Page 25: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/25.jpg)
25
Conjugate Pairs Examples
Nitrous Acid
HNO2 (aq) + H2O H3O+ + NO2-
Conjugate Acid Base Pairs
The conjugate base of HNO2 is NO2-,
the species that remains after HNO2 loses a proton.
acidacid base base conjugate conjugateconjugate conjugate acid acid
basebase
![Page 26: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/26.jpg)
26
Conjugate Pairs Examples
Ammonia
NH3(aq) + H2O OH- + NH4+
Conjugate Acid Base Pairs
basebase acid acid conjugate conjugateconjugate conjugate base base acid acid
Notice acid-base pairs only differ by one proton (H+)
![Page 27: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/27.jpg)
NH3(aq) + H3O+(l)
![Page 28: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/28.jpg)
Arrhenius vs. Brønsted Lowry
28
![Page 29: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/29.jpg)
29
Strong Acids
• Acids that are completely ionized in water solution are called strong acids.
H2O
HCl(g) -> H+(aq) + Cl-(aq)
In 0.0010 mol/L HCl(aq)[H+] = 0.0010 mol/L[Cl-] = 0.0010 mol/L[HCl] = 0 mol/L
Square Brackets indicates concentration
All the HCl is dissociatedin solution
![Page 30: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/30.jpg)
30
Weak Acids• Acids that are only partially ionized in
aqueous solution are called weak acids.
In 1.00 mol/L CH3COOH(aq) only about 1% of the molecules ionize, most of it remains as acetic acid molecules
H2O
CH3COOH(aq) H+ (aq) + CH3COO-
(aq)
In 1.000 mol/L CH3COOH (aq)
[H3O+] or [H+] = 0.010 mol/L [CH3COO-] = 0.010 mol/L[CH3COOH] = 0.99 mol/L
![Page 31: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/31.jpg)
31
Monoprotic Acids
• One ionizable H atom per molecule– Hydrochloric Acid HCl– Hydrofluoric Acid HF
– Nitric Acid HNO3
– Hydrocyanic Acid HCN
![Page 32: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/32.jpg)
32
Polyprotic Acids
• Diprotic AcidsTwo ionizable H atoms per molecule
– Sulfuric Acid H2SO4
– Carbonic Acid H2CO3
• Triprotic AcidsThree ionizable H atoms per molucule
– Phosphoric Acid H3PO4
![Page 33: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/33.jpg)
33
Not all Hydrogens are Acidic
• None of the hydrogens in methane (CH4) are given up in acidic solution
• Only one hydrogen in acetic acid (C2H4O2) is acidic, that is why it is often written as CH3COOH
![Page 34: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/34.jpg)
34
How to tell the acidic hydrogens
1. We write a molecular formula with ionizable H atoms first.– HNO3 , H2SO4 , and H3PO4
– HC2H3O2,
Ionizable Hydrogens
Non-Ionizable Hydrogens
![Page 35: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/35.jpg)
35
How to tell the acidic hydrogens
2. In organic chemistry, we often use formulas that show the ionizable hydrogen atoms last.
Example carboxylic acids. Acetic acid CH3COOHFormic acid HCOOH
Propionic acid CH3CH2COOH
Butyric acid CH3CH2CH2COOH
In each of these, only the H atom on the O atom is ionizable.
Ionizable Hydrogens
Non-Ionizable Hydrogens
![Page 36: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/36.jpg)
36
Common Strong Acids
Hydrochloric acid HCl(aq)
Hydrobromic acid HBr(aq)
Hydriodic acid HI(aq)
Nitric acid HNO3(aq)
Sulfuric acid H2SO4(aq)
Perchloric acid HClO4(aq)
![Page 37: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/37.jpg)
37
Common Bases• Bases produce OH- ions in aqueous solution
(Arrhenius definition)– Group 1 and 2 cations with hydroxide ions
• Examples:
NaOH Sodium Hydroxide (also known as lye)
KOH Potassium Hydroxide
Ca(OH)2 Calcium Hydroxide (a.k.a. slaked lime)
H2O
NaOH (s) Na+ (aq) + OH-
(aq)
Strong bases are completely ionize in water:Strong Bases
![Page 38: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/38.jpg)
38
Strong BasesAlkali metal hydroxides
Lithium hydroxide LiOH (aq)
Sodium hydroxide NaOH (aq)
Potassium hydroxide KOH (aq)
Rubidium hydroxide RbOH (aq)
Cesium hydroxide CsOH (aq) Alkaline earth hydroxides
Calcium hydroxide Ca(OH)2 (aq)
Strontium hydroxide Sr(OH)2 (aq)
Barium hydroxide Ba(OH)2 (aq)
![Page 39: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/39.jpg)
39
Weak Bases
Bases that are only partially ionized in aqueous solution are called weak bases.
H2O
NH3 (g) + H2O NH4+
(aq) + OH- (aq)
![Page 40: 1 - SCH3U1 - Acids and Bases Sections 10.1. 2 Learning Goals 1.What is Arrhenius's definition of an acid? A base? 2.What is the Brønsted-Lowry definition.](https://reader036.fdocuments.in/reader036/viewer/2022062515/56649f435503460f94c62f1c/html5/thumbnails/40.jpg)
40
Ammonia as a proton acceptor
• Lone pair can be used to accept proton