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Acid, Bases, and Salts. Chemistry—Part 1. I. Acids. H   is a nonmetal or polyatomic ion  could be Cl - , SO 4 2- , etc. Ex: HCl, HF, H 2 SO 4 , HClO 4 , H 3 PO 4. Acids (con’t). dissociate to form H + ions (protons) Hydrogen Atom Hydrogen Ion (proton). e -. +.

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Acid bases and salts

Acid, Bases, and Salts

Chemistry—Part 1


I acids
I. Acids

H

 is a nonmetal or polyatomic ion

 could be Cl- , SO42-, etc.

Ex: HCl, HF, H2SO4 , HClO4, H3PO4


Acids con t
Acids (con’t)

dissociate to form H+ ions (protons)

Hydrogen AtomHydrogen Ion(proton)

e-

+


A ionization in water
A. Ionization in Water

H3O+ + Cl-

HCl + H2O 

H+ combines with H2O to form H3O+

Hydronium Ion

H+(proton) is attracted to lone e- pairs in H2O

+

-


Try this
Try This:

H2SO4 + H2O 

H3PO4 + H2O 

2

2 H3O+ + SO42-

+

SO42-

SO42-

+

3

3 H3O+ + PO43-


B examples
B. Examples

  • Soda pop – H2CO3, H3PO4

  • Vinegar (acetic acid) – HC2H3O2

  • Lemons – citric acid

  • Stomach acid – HCl

  • Battery acid – H2SO4

  • Sour Patch Kids – Tartaric Acid


C properties
C. Properties

  • taste sour

  • conduct electricity

  • turn litmus red

  • react with some metals to produce H2 (g) Remember, Zn + 2HCl  ZnCl2 + H2(g)

  • corrosive

  • All form H+ ions in solution


Ii bases
II. Bases

contain OH- (hydroxide ions)

Ex: Ca(OH)2, LiOH, NH4OH, NaOH

Also calledalkaline (alkali)

Alkali Flats

Bonneville Salt Flats, Utah


A ionization in water1
A. Ionization In Water

H2O

NaOH Na+ + OH-

NH4OH

Ca(OH)2

H2O

NH4+ + OH-

H2O

Ca2+ + 2 OH-


B examples1
B. Examples

  • Drano – NaOH

  • Oven cleaner – KOH

  • Tums – Ca(OH)2

  • Glass cleaner – NH4OH


C properties1
C. Properties

  • Taste bitter (Baking Soda)

  • Conduct electricity

  • Turn litmus blue

  • Feel slippery (hard to wash off of skin)

  • Caustic (dissolves protein, ie. YOU)

  • Form OH- ions


Iii reactions of acids and bases
III. Reactions of Acids and Bases

Neutralization:

Acid + Base  Salt + Water

HBr + NaOH 

Type of reaction?

NaBr + H2O

DOUBLE DISPLACEMENT!


Try this1
Try This:

HF + LiOH 

H2SO4 + KOH 

HOH + LiF

(H2O)

H2O + K2SO4

2

2


Antacids
Antacids

Neutralize stomach acid

Ex: Tums

HCl + Ca(OH)2 

Milk of Magnesia (demo)

HCl + Mg(OH)2 

2

H2O + CaCl2

2

H2O + MgCl2

2

2


Iv electrolyte solutions
IV. Electrolyte Solutions

Substances whose water solutions conduct electricity

NaCl (c) vs. NaCl (aq)

Sucrose (c) vs. Sucrose (aq)

H2O (distilled) vs. H2O (tap)

There must be ions present to conduct


Strong weak electrolytes
Strong & Weak Electrolytes

NaCl (s)

HF (s)

HF

F+

Na+

Cl-

HF

HF

Na+

H+

Cl-

Na+ + Cl-

only ions are present

H+ + F-

mostly HF present;

only some ions

STRONG ELECTROLYTES

Ionize 100%

NaCl 

WEAK ELECTROLYTES

Only partially ionize

HF 


Conductivity demo
Conductivity Demo

NH4OH + HC2H3O2

H2O + NH4C2H3O2

Weak

Base

Weak

Acid

Salt


Practice
Practice

H?

?OH

HBr

LiOH

H2CO3

KOH

H2SO4

NH4OH


Lab 49 pre lab
Lab 49 Pre - Lab

NaCl 

FeCl3 

C6H12O6 

Na+ (aq) + Cl- (aq)

Fe3+ (aq) + 3 Cl- (aq)

C6H12O6 (aq)


V naming acids bases salts
V. Naming Acids, Bases & Salts

Acid Names

1. Binary Acids

contain only TWO elements

ex: HCl Hydrochloric Acid

Hydro-stem-ic Acid

Try: HBr

HF

H2S

Hydrobromic Acid

Hydrofluoric Acid

Hydrosulfuric Acid


  • Ternary Acids

    contain THREE elements (usually)

    contain H and a polyatomic ion

    ate icite  ous

    ex: H2CO3 carbonate carbonic

    Carbonic Acid


Try these
Try These

HNO2

nitrite nitrous

Nitrous Acid

HNO3

nitrate nitric

Nitric Acid

H2SO3

sulfite sulfurous

Sulfurous Acid

H2SO4

sulfate sulfuric

Sulfuric Acid


Base names iupac nomenclature
Base Names (IUPAC Nomenclature)

Combine names of ions

NaOH

Sodium Hydroxide

Ca(OH)2

Calcium Hydroxide


Salt names
Salt Names

Combine names of ions

NaBr

Sodium Bromide

K2SO4

Potassium Sulfate

Cu(NO3)2

Copper (II) Nitrate


Vi salts
VI. Salts

Salts are ionic and crystalline


A dissociation in water
A. Dissociation in Water

Salt Cation + Anion

LiCl

Na2SO4

H2O

H2O

Li+ + Cl-

H2O

2 Na+ + SO42-


B cation and anion
B. Cation and Anion

Cation: Positive (+) charge

The ___________ contributes the cation

(acid/base?)

Anion: Negative (-) charge

The ___________ contributes the anion

(acid/base?)


C examples
C. Examples

Na+

Cl-

Na+

HCO3-

K+

SO42-


Parent acid parent base
Parent Acid / Parent Base

Parent Acid: The acid that contributes the ANION to the salt

Parent Base: The base that contributes the CATION to the salt


Viii strong acids and bases
VIII. Strong Acids and Bases

STRONG ACIDS—DISSOCIATE 100 %

HCl HNO3 H2SO4

STRONG BASES—DISSOCIATE 100%

All Alkali Metals (IA) form strong bases


Viii weak acids and bases
VIII. Weak Acids and Bases

WEAK ACIDS—DO NOT DISSOCIATE 100 %

WEAK BASES—DO NOT DISSOCIATE 100%

How would a weak acid conduct electricity compared to a strong acid?


Ix polyprotic acids
IX. Polyprotic Acids

Acids with more than one proton (H+)

  • Examples

    H2SO4 H3AsO4 H3PO4 H2CO3 H2S


B step by step ionization
B. Step – By – Step Ionization

Acids lose one proton at a time

1st H3PO4

2nd H2PO4- 

3rd HPO4-2 

H3PO4  3H+ + PO43-

H+ +

H2PO4-

H+ +

HPO4-2

H+ +

PO4-3

H3PO4 + H2O 

3

3 H3O+ + PO43-


Questions
Questions

1. Which of the following are polyprotic acids?

a) HCl d) HC2H3O2

b) NH3 e) H3PO4

c) H2SO4 f) HNO3

2. Which acid is harder to ionize: H3PO4 or HPO4-2? Why?

The -2 charge attracts protons (H+)

3. Which acid is stronger: H2SO4 or HSO4-? Why?

easier to lose protons (H+)



Water as an acid and a base
Water as an acid and a base

amphoteric:

water behaves as an acid & base

H2O + H2O  H3O+ + OH-

acidbaseconjconj

acidbase


X anhydrides
X. Anhydrides

Without water

Acidic Anhydrides—

non-metallic oxides that combine with H2O to form an acid

SO2 + H2O  H2SO3

CO2 + H2O 

H2CO3

Acid Anhydrides


Basic Anhydrides—

metal oxides that combine with H2O to form a base

CaO + H2O  Ca(OH)2

Na2O + H2O 

2 NaOH

Basic Anhydrides


Try these acidic or basic anhydride
Try These: Acidic or Basic Anhydride?

K2O

Basic Anhydride

NO2

Acidic Anhydride



Acid bases and salts1

Acid, Bases, and Salts

Chemistry—Part 2


I molarity
I. Molarity

Example: 6 KOH 0.1 H2SO4 2 NaCl

A measure of concentration

M

M

M


Concentration
Concentration

6 M

1 M


Examples
Examples

3 M HNO3 =

20 moles in 5 L = ? M


Try this2
Try This!

If 80 grams of NaOH (MW=40) is dissolved in 2 L, find the molarity.

6 moles of HBr in 250 ml. Molarity?


Now try this one
Now Try This One!

How many moles of HCl are in 500 ml of a 3 M solution?


Ii titration
II. Titration

Using a solution of to determine the concentration of another solution.

A neutralization reaction

Acid + Base 

known concentration

Salt + Water


End point
End Point

The point at which neutralization is complete

moles H+ = moles OH-

use (like phenolphthalein) to determine the end point

acid-base indicators


Acidic—before neutralization

Neutral—

”End Point”

Basic—

“overshot endpoint”


NaOH

HCl 

H2SO4

Na+ + OH-

50 ml

1 M

1 M

H+ + Cl-

50 ml

1 M

1 M

2 H+ + SO42-

25 ml

1 M

2 M


NaOH  Na+ + OH-

HCl  H+ + Cl-

50 ml

1 M

1 M

25 ml

2 M

2 M


Titration equation
Titration Equation

MA = Molarity of Acid

VA = Volume of Acid

#H+= Number of H’s in acid formula

UNITS MUST MATCH!!!

MB = Molarity of Base

VB = Volume of Base

#OH- = Number of OH’s in base formula


Try this3
Try This

50 ml of 0.1 M NaOH is neutralized by 5 ml of HCl. Find the molarity of the acid.

(5ml)(1H+)

(5ml)(1H+)


Try this4
Try This

40 ml of 1M KOH is neutralized by 10 ml of sulfuric acid. Find the molarity of acid.

(10ml)(2H+)

(10ml)(2H+)


Iii indicators
III. Indicators

Weak organic acids or bases that are a different color in an acid than in a base

Ex:

Phenolpthalein

Bromothymol Blue

Litmus

Red Cabbage


Limitations of indicators
Limitations of Indicators

Solutions must be colorless

Eye must be able to detect the change


Iv ionization of water
IV. Ionization of Water

[ ] stands for

concentration

In pure water, [H+] = 10-7 M and [OH-] = 10-7 M

1 water out of 10,000,000 forms ions


K w water s ionization constant
Kw – water’s ionization constant

Kw = [H+] [OH-]

Kw = (10-7) (10-7)

Kw = 10-14

so…

10-14 = [H+][OH-]

CONSTANT

Add Acid?

Add Base?


Example 1
Example #1

[OH-] = 10-6 M [H+] = ?


Example 2
Example #2

[H+] = 10-3 M [OH-] = ?


Ph scale
pH Scale

Used to measure acidity

Based on the concentration of H+ ions


When

the [H+] increases by 10,

the pH decreases by 1.

When

the pH increases by 2,

the [H+] decreases by _____

102 = 100


Ph log h
pH = -log[H+]

4

[H+] = 10-4 pH = ______ acidic or basic?

[H+] = 10-11 pH = ______ acidic or basic?

11


Poh log oh
pOH = -log[OH+]

3

[OH-] = 10-3 pOH = ______

[H+] = 10-9 pOH = ______

5


Ph poh 14
pH + pOH = 14

Why?

[H+] [OH-] = 10-14

(10-7) (10-7) = 10-14

pH + pOH = 14

- log

- log


Try these1
Try These:

For a solution that is 0.1 M HCl…

  • What is the pH?

  • What is the concentration of OH- ions?

  • What is the pOH?

    For a solution that is 0.001 M NaOH…

  • What is the pOH?

  • What is the pH?

  • What is [H+]?

    For a solution that has a pH of 8…

  • What is the [H+]?


Hydrolysis
Hydrolysis

The reaction of a salt with water to form an acidic or basic solution

Recall Strong Acids:

Recall Strong Bases:

HCl HNO3 H2SO4

Group IA Hydroxides



Ex naf
Ex: NaF

Parent Acid:

Parent Base:

So…NaF is BASIC

HF

strong or weak?

NaOH

strong or weak?


Try this fe no 3 3
Try This: Fe(NO3)3

Parent Acid:

Parent Base:

So…Fe(NO3)3 is ACIDIC

HNO3

strong or weak?

Fe(OH)3

strong or weak?


Try this nacl
Try This: NaCl

Parent Acid:

Parent Base:

So…NaCl is NEUTRAL

HCl

strong or weak?

NaOH

strong or weak?


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