# Zumdahl Ch 19, 20, 21, 22 Elements powerpoint

## Full text

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### The

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Section 19.1

A Survey of the Representative Elements

Topics of weakness on 3rd Quarter final 2018

1. temperature and Le Châtelier’s principle

Higher temp favors the endothermic direction! 2. M Ksp

Write an equation like Al(OH)3 Al3+ +

3OH- Then write a Ksp expression: Ksp = x (3x)3

Solve for Ksp

3. Find pH of a solution being titrated

Stoichiometry, then equilibrium…

… using Henderson-Hasselbalch; pH = pKa + log [b]/[a] 4. Relationship between Keq and ΔGo

ΔGo = -RT ln K

eq therefore large negative ΔGo  large

Keq!

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Section 19.1

A Survey of the Representative Elements

Topics of weakness on 3rd Quarter final 2018

5. Electroplating; math problems

6. Finding Eo from table and using Nernst equation

7. Titration problems non-acid/base

8. Identifying oxidizing agent

9. Finding Eo in the positive direction when you calculate

a negative value.

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Chapter 19

19.1A Survey of the Representative Elements 19.2 The Group 1A Elements

19.3 The Chemistry of Hydrogen 19.4The Group 2A Elements

19.5The Group 3A Elements 19.6 The Group 4A Elements 19.7 The Group 5A Elements 19.8The Chemistry of Nitrogen

19.9 The Chemistry of Phosphorus 19.10 The Group 6A Elements

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Section 19.1

A Survey of the Representative Elements

### Objectives:

Students will know the important patterns and trends on the periodic table.

Students will predict products of chemical reactions involving hydrogen.

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Section 19.1

A Survey of the Representative Elements

Reviewing the Periodic Table Regions

Representative elements:

Groups 1A – 8A (filling s and p orbitals)

Transition elements:

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Section 19.1

A Survey of the Representative Elements

Reviewing the Periodic Table Regions

Lanthanides and actinides:

Listed separately, on the bottom of the table (filling 4f and 5f orbitals)

Metalloids:

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Section 19.1

A Survey of the Representative Elements

The atomic radii of some representative elements (in

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Section 19.1

A Survey of the Representative Elements

Concept Check

Which should be the larger atom? Why?

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Section 19.1

A Survey of the Representative Elements

Concept Check

Which should be the larger atom? Why?

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Section 19.1

A Survey of the Representative Elements

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Section 19.1

A Survey of the Representative Elements

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Section 19.2

Atomic Masses

The Group 1A Elements

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Section 19.2

Atomic Masses

The Group 1A Elements

Reactions of Group 1A metals

In the presence of oxygen: 4Li + O2  2Li2O

In the presence of water:

2M(s) + H2O(l)  2M+

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Section 19.2

Atomic Masses

The Group 1A Elements

In the presence of excess oxygen: 2Na + O2  Na2O2(s)

sodium peroxide (contains O22-)

K + O2  KO2(s)

potassium superoxide (contains O2-)

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Section 19.2

Atomic Masses

The Group 1A Elements

Exercise

Predict the products formed by the following reactants:

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Section 19.2

Atomic Masses

The Group 1A Elements

End of lesson

But let us continue….

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Section 19.3 The Mole

The Chemistry of Hydrogen

Hydrides

(binary compounds containing hydrogen) Ionic hydrides: hydrogen + very active metal

(ex: LiH, CaH2)

Note: LiH(s) + H2O(l) H2(g) + Li+

(aq) + OH-(aq)

Covalent hydrides:

hydrogen + other nonmetals

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Section 19.3 The Mole

The Chemistry of Hydrogen

Hydrides

Metallic (interstitial) hydrides:

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Section 19.3 The Mole

The Chemistry of Hydrogen

Reaction predictions

Flash cards are strongly recommended for studying reaction predictions. Put reactants on one side and products on the other!

Try googling “AP Chemistry reaction prediction flashcards”

Has anyone tried this?

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Section 19.3 The Mole

The Chemistry of Hydrogen

Exercise

Predict the products formed by the following reactants:

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Section 19.4

The Group 2A Elements

Alkaline earth metals

Very reactive

Great practical importance:Human life (Ca and Mg)

Essential for:

protein synthesis

muscle and nerve function

blood glucose control

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Section 19.4

The Group 2A Elements

Reactions of Group 2A

MO(s) + H2O(l) M2+

(aq) + 2OH-(aq)

Ca, Sr, and Ba:

M(s) + 2H

2O(l) M2+(aq) + 2OH-(aq) + H2(g)

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Section 19.4

The Group 2A Elements

More reactions of Group 2A (see p. 886)

M + X2 MX2 where X2 = any halogen

2M + O2 2MO Ba gives BaO2 also

M + S MS

3M + N2 M3N2

6M + P4 2M3P2

M + H2 MH2

M + 2H+ M2+ + H

2 (meaning M reacts w/

acid)

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Section 19.4

The Group 2A Elements

Ion Exchange

Ca2+ and Mg2+ are often removed during ion

exchange, releasing Na+ into solution.

Ion exchange resin = large molecules with

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Section 19.4

The Group 2A Elements

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Section 19.4

The Group 2A Elements

End of lesson

• See homework on board.

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Section 19.5

The Group 3A Elements

Group 3A elements generally show the

increase in metallic character in going down the group that is characteristic of the

representative elements.

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Section 19.5

The Group 3A Elements

Aluminum

Aluminum is easily oxidized:

Al3+ + 3e-  Al

(s) E ° = -1.66 V

But it resists corrosion due to a surface

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Section 19.5

The Group 3A Elements

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Section 19.6

The Group 4A Elements

Contains two of the most important

elements on earth: carbon and silicon.

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Section 19.6

The Group 4A Elements

Si is easily produced from silica sand (SiO2).

SiO2(s) + 2C(s)  Si(s) + 2 CO(g)

Contrast SiO2 with CO2:

network solid;

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Section 19.6

The Group 4A Elements

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Section 19.6

The Group 4A Elements

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Section 19.7

The Group 5A Elements

… exhibit varied chemical properties:

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Section 19.8

The Chemistry of Nitrogen

Nitrogen

N2 is nonreactive due to the strong triple bond. This causes most binary compounds containing N to decompose exothermically into the elements:

NO2(g)  ½N2(g) + O2(g)

Δ ≈ - 34 kJ

N2H4(g)  N2(g) + 2H2(g)

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Section 19.8

The Chemistry of Nitrogen

Nitrogen reactions

3Mg + N2  Mg3N2

The Haber Process:

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Section 19.8

The Chemistry of Nitrogen

Reactions of nitrogen compoundsNH3 + H2O  NH4+ + OH

-Kb = 1.8 x 10-5

2NH3 + NaOCl  N2H4 + NaCl + H2O

N2H4 + H2O  N2H5+ + OH-

weak base Kb = 8.5 x 10-7

N2H4 + 4OH-  N

2 + 4H2O + 4e

-strong reducing agent

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Section 19.8

The Chemistry of Nitrogen

Reactions of nitrogen oxides

NH4NO3(s)  N2O(g) + 2H2O(g)

nontoxic, odorless, “laughing gas”

2HNO3(aq)  2NO2(g) + H2O(l) + ½ O2

2NO(g) + O2(g)  2NO2(g)

brown haze of smog

2NO2  N2O4

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Section 19.8

The Chemistry of Nitrogen

Reactions involving nitric acid

Nitric acid is both a strong acid and a strong oxidizing agent.

N2O4 + H2O  HNO3 + HNO2

2NaNO3 + H2SO4  2HNO3 + Na2SO4

Dilute HNO3 reacts with copper:

3Cu(s) + 8H3O+

(aq) + 2NO3-(aq)

3Cu2+

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Section 19.8

The Chemistry of Nitrogen

Reactions involving nitric acid

Concentrated HNO3 reacts with copper:

Cu(s) + 4H3O+

(aq) + 2NO3-(aq)

Cu2+

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Section 19.8

The Chemistry of Nitrogen

Nitrogen fixation

The process of transforming N2 to other nitrogen–containing compounds:

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Section 19.8

The Chemistry of Nitrogen

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Section 19.8

The Chemistry of Nitrogen

In nitrogen oxides, N has oxidation states from +1 to +5.

In other compounds, N has oxidation states of -1 to -3.

2

2

3

2

### +4

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Section 19.8

The Chemistry of Nitrogen

Reactions of nitric and nitrous acid

Nitric acid, HNO3

Nitrous acid, HNO2

3 2 2 2

hv

### g

+

2 2

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Section 19.9

The Chemistry of Phosphorus

Allotropes of phosphorus

White phosphorus = P4 (tetrahedral) - very reactive

Black phosphorus = crystalline structure - much less reactive

Red phosphorus = amorphous with P4 chains

heat, 1 atm, no air

(white) (red)

P  P

high pressure

(white) or (red) (black)

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Section 19.9

The Chemistry of Phosphorus

Allotropes of phosphorus

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Section 19.9

The Chemistry of Phosphorus

Phosphorus oxyacids

phosphoric acid, H3PO4

phosphorous acid, H3PO3

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Section 19.9

The Chemistry of Phosphorus

How is phosphorus obtained?

2Ca3(PO4)2(s) + 10C(s) + 6SiO2 (s) P4(g) + 10CO(g) + 6CaSiO3(s)

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Section 19.10

The Group 6A Elements

O, S, Se, Te, Po

Although in Group 6A there is the usual

tendency for metallic properties to increase going down the group, none of the Group 6A elements behaves as a typical metal.

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Section 19.11

The Chemistry of Oxygen

O is present in crust (minerals) and atmosphere (obviously).

O3 (ozone) exists in the upper atmosphere of the Earth; a less stable allotrope.

Ozone layer absorbs UV light and acts as a screen to prevent it from penetrating to the Earth’s surface.

Scientists are concerned that freons (CFCs) and

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Section 19.11

The Chemistry of Oxygen

Ozone

### 3O

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Section 19.12

The Chemistry of Sulfur

Sulfur is found in nature both as the free

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Section 19.12

The Chemistry of Sulfur

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Section 19.12

The Chemistry of Sulfur

Reactions involving sulfur compounds

2ZnS(s) + 3O2(g)  2ZnO(s) + 2SO2(g)

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Section 19.12

The Chemistry of Sulfur

Sulfur oxide reactions

2SO2(g) + O2(g)  2SO3(g)

Colorless, toxic; Choking odor

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Section 19.13

The Group 7A Elements

Halogens

All nonmetals: F, Cl, Br, I, At

Because of their high reactivities, the halogens are not found free in nature. They are found as halide ions (X–) in minerals and in seawater.

Cl2 is a yellow-green gas formed from NaCl.

Cl forms many oxyacids (see p. 928.)

2NaCl + H2SO4  Na2SO4 + 2HCl

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Section 19.13

The Group 7A Elements

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Section 19.13

The Group 7A Elements

Preparation of hydrogen halides

H2(g) + X2(g)  2HX(g)

When dissolved in water, the hydrogen halides

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Section 19.13

The Group 7A Elements

Halogen oxyacids and oxyanions

All halogens except fluorine combine with

various numbers of O atoms to form a series of oxyacids.

The strengths of these acids vary in direct

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Section 19.14

The Group 8A Elements

Noble Gases

He and Ne form no compounds.

Kr and Xe have been observed to form compounds:

Xe(g) + 2F2(g)  XeF4(s) [6 atm, 400oC]

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Section 19.14

The Group 8A Elements

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Section 19.14

The Group 8A Elements

Concept check

Which of the following groups is the most

reactive?

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Section 19.14

The Group 8A Elements

Concept check

Which of the following groups contain no

element that forms compounds with oxygen? a) Group 4A Elements

b) Group 5A Elements

c) Group 6A Elements d) Group 7A Elements

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Section 19.14

The Group 8A Elements

PES – Photoelectron Spectroscopy

v=gyKD6QULa0A

• (seems to have a slight error at the end?)

• http://www.sophia.org/tutorials/ap-chemistry-pes

Mass Spectroscopy

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Section 19.14

The Group 8A Elements

### This is Mg.

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Section 19.1

A Survey of the Representative Elements

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Section 19.14

The Group 8A Elements

End of lesson

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Section 19.13

The Group 7A Elements

Objectives:

Students will know the characteristics of transition metals and their compounds.

Students will know how to name these compounds.

### Chapter 21

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Section 19.13

The Group 7A Elements

Transition metals

• Transition metals are similar within a period. • > 1 oxidation state is possible.

• Compounds are colorful due to light absorption by a partially filled d sublevel.

### Chapter 21

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Section 19.13

The Group 7A Elements

Coordination compound =

Coordination complex (complex ion) +

### Chapter 21

Coordination compounds

Counter ion

Transition metal ion [Lewis acid]

Ligand (attached molecules or

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Section 19.13

The Group 7A Elements

Coordination compounds

[Co(NH3)5Cl]Cl2

Chapter 21

Coordination compounds

T.M. ion Ligands Counter ions

Note: Co has an oxidation state of +3.

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Section 19.13

The Group 7A Elements

Ligands

### Chapter 21

Ligands Anionic ligands names Neutral ligands names

Br- bromo NH

3 ammine

F- fluoro H

2O aqua

O2- oxo NO nitrosyl

OH- hydroxo CO carbonyl

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Section 19.13

The Group 7A Elements

Monodentate ligands

### Chapter 21

Ligands

Bidentate ligands

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Section 19.13

The Group 7A Elements

Naming coordination compounds

### Chapter 21

Ligands

Go over rules on p. 958.

Go over examples on p. 958. Example 21.1

Fe4[Fe(CN)6]3

iron (III) hexacyanoferrate (II)

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Section 19.13

The Group 7A Elements

Naming coordination compounds

### Chapter 21

Ligands

Try this one:

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Section 19.13

The Group 7A Elements

### Chapter 21

Ligands

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Section 19.13

The Group 7A Elements

### Chapter 22

Organic Compounds

Students will be able to name and draw various organic compounds.

### Chapter 22

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Section 19.13

The Group 7A Elements

### Chapter 22

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Section 19.13

The Group 7A Elements

n

2n+2

n

2n

n

2n

n

2n–2

### aromatics

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Section 19.13

The Group 7A Elements

4

2

2

### Chapter 22

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Section 19.13

The Group 7A Elements

### Chapter 22

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Section 19.13

The Group 7A Elements

2

3

## CHOCOLATE!

### Chapter 22

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Section 19.13

The Group 7A Elements

### Chapter 22

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Section 19.13

The Group 7A Elements

### Chapter 22

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Section 19.13

The Group 7A Elements

n

2n+2

3

2

n–2

3

### Chapter 22

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Section 19.13

The Group 7A Elements

Naming of alkanes

First four are named historically:

CH4, methane (“intoxicate” from the Greek)

ethane, propane, and butane for 2, 3, 4.

After n=4, the prefixanes have Greek numbers as their prefixes.

5 = pent, 6 = hex, 7 = hept, 8 = oct, 9 = non, and 10 = dec, 20 = eicos, 30 = triacos

### Chapter 22

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Section 19.13

The Group 7A Elements

### Chapter 22

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Section 19.13

The Group 7A Elements

### Chapter 22

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Section 19.13

The Group 7A Elements

n

2n

### E.g., BOAT cyclohexane versus CHAIR

See the C 3 and S

6 here?

### Chapter 22

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Section 19.13

The Group 7A Elements

Alkenes, CnH2n

Cycle formation isn’t the only possible result of dehydrogenation.

Adjacent C’s can double bond, C=C, making an (unsaturated) alkene.

Much more reactive (vulnerable e– pair)

Rigid orbitals rigid planar partners!

E.g., trans-5-methyl-2-hexene

Obligatory plane seen edge on

### Chapter 22

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Section 19.13

The Group 7A Elements

Alkene Isomers

While an sp3 CX

2Y2 has only 1 isomer,

(every X and Y is adjacent to all the others)

the sp2 alkene C

2X2Y2 has cis & trans isomers

(where X is or isn’t on the same side of = as X).

For longer hydrocarbons, cis & trans refer to the side the chain extends:

and trans for the opposite

cis-2-butene trans-2-butene

cis for the same side

### Chapter 22

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Section 19.13

The Group 7A Elements

Alkynes, CnH2n–2

sp triple bonding makes a rigid 180° segment in a hydrocarbon.

It too is vulnerable to attack across the multiple bond site.

Double & triple bonds can suffer addition where an AB molecule single bonds A and B to an

unsaturated site. H2, HX, and X2 (where X is halogen) are favorites.

propyne

### Chapter 22

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Section 19.13

The Group 7A Elements

Unsaturated Cycles

Earlier we noted the stability lent to benzene, C6H6, by MOs.

Alternating single/double cycles occur in many organic molecules similarly.

This class is called “aromatic” (by virtue of their aroma).

The structure is often preserved in their chemical reactions; they don’t add, they substitute instead.

bromobenzene anthracene (edge on)

### Chapter 22

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Section 19.13

The Group 7A Elements

Functional groups

• Organic backbones can bear hetero-atoms as reactive sites.

• Alkyl root symbolized as R, a generic

hydrocarbon radical (methyl, ethyl, etc.) • Functional groups append R, e.g.,

R–OH, an alcohol, or R–CHO, aldehyde. R–CO2H, a carboxylic acid, R–NH2, amine.

isobutraldehyde or

methylpropanal

### Chapter 22

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Section 19.13

The Group 7A Elements

Alcohols, R–OH

The –OH makes alcohol polar enough to hydrogen bond. water soluble

Fermentation product but vulnerable to oxidation to aldehyde and acid.

glucose, C

6H12O6

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Section 19.13

The Group 7A Elements

Aldehydes, R–CHO

• Next C oxidation state up from alcohol. – Degradation product in your liver!

• If C=O isn’t a chain end substituent, it’s not an

aldehyde but a ketone.

• Aldehydes are often flavorings, but • Ketones are industrial solvents.

O C H

benzaldehyde,

“bitter almond”

quinone

### Chapter 22

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Section 19.13

The Group 7A Elements

Carboxylic Acids

2

### H

Usual highest C ox. state in organics.

End product of body’s alcohol degradation.

Weakly acidic but important buffers.

React with alcohols to make highly flavorful esters … a condensation rxn.

O C

OH

+  +

butanoic acid

“rancid yak butter”

ethanol ethyl butyrate

“pineapple”

water

### Chapter 22

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Section 19.13

The Group 7A Elements

Amines, Rn–NH3–n

Come in three varieties.

“Primary” amines, N is at chain end.

“Secondary” amine N bonds to 2 carbons.

“Tertiary” amines bond to 3 carbons.

Weak base Kb diminishes as n increases.

Alcohols are also primary, secondary, and tertiary. (Primary are on end carbons.)

But this refers to the bonding of the C to which OH is attached.

Coniine (2ndary) “hemlock”

2-propyl-piperidine

### Chapter 22

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Section 19.13

The Group 7A Elements

Mixed Functionality

• So H2NCH2CH2OH is an alcohol and an amine; it

becomes ethanolamine.

• But the monster C9H14N4O3 would be agony to call by its IUPAC name.

– So it’s known by it common name, carnosine.

How many K

a and Kb are expected? 1 and 4, respectively.

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