Zumdahl Ch 19, 20, 21, 22 Elements powerpoint

(1)

Chapter 19

The

(2)

Section 19.1

A Survey of the Representative Elements

Return to TOC

Topics of weakness on 3rd Quarter final 2018

1. temperature and Le Châtelier’s principle

 Higher temp favors the endothermic direction! 2. M  K_sp

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

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

 Solve for K_sp

3. Find pH of a solution being titrated

 Stoichiometry, then equilibrium…

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

 ΔGo = -RT ln K

eq therefore large negative ΔGo  large

K_eq!

(3)

Section 19.1

Return to TOC

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.

(4)

Chapter 19

Table of Contents

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

(5)

Section 19.1

Return to TOC

Objectives:

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

• Students will predict products of chemical reactions involving hydrogen.

(6)

Section 19.1

Return to TOC

Reviewing the Periodic Table Regions

• Representative elements:

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

• _{Transition elements:}

(7)

Section 19.1

Return to TOC

Reviewing the Periodic Table Regions

• Lanthanides and actinides:

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

• Metalloids:

(8)

Section 19.1

Return to TOC

The atomic radii of some representative elements (in

(9)

Section 19.1

Return to TOC

Copyright © Cengage Learning. All rights reserved 9

Concept Check

Which should be the larger atom? Why?

(10)

Section 19.1

Return to TOC

Concept Check

Which should be the larger atom? Why?

(11)

Section 19.1

Return to TOC

(12)

Section 19.1

Return to TOC

(13)

Section 19.2

Atomic Masses

The Group 1A Elements

Return to TOC

(14)

Section 19.2

Atomic Masses

Return to TOC

Reactions of Group 1A metals

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

• _{In the presence of water:}

2M_(s) + H₂O_(l)  2M+

(15)

Section 19.2

Atomic Masses

Return to TOC

• In the presence of excess oxygen: 2Na + O₂  Na₂O_2(s)

sodium peroxide (contains O₂2-)

K + O₂  KO_2(s)

potassium superoxide (contains O₂-)

(16)

Section 19.2

Atomic Masses

The Group 1A Elements

Return to TOC

Exercise

Predict the products formed by the following reactants:

(17)

Section 19.2

Atomic Masses

Return to TOC

End of lesson

• But let us continue….

(18)

Section 19.3 The Mole

The Chemistry of Hydrogen

Return to TOC

Hydrides

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

(ex: LiH, CaH₂)

Note: LiH_(s)+ H₂O_(l) H_2(g) + Li+

(aq) + OH-(aq)

 Covalent hydrides:

hydrogen + other nonmetals

(19)

The Chemistry of Hydrogen

Return to TOC

Hydrides

 Metallic (interstitial) hydrides:

(20)

Return to TOC

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?

(21)

Section 19.3 The Mole

Return to TOC

Exercise

Predict the products formed by the following reactants:

(22)

Section 19.4

Return to TOC

Alkaline earth metals

• Very reactive

• Great practical importance:  Human life (Ca and Mg)

Essential for:

protein synthesis

muscle and nerve function

blood glucose control

(23)

Section 19.4

Return to TOC

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)

(24)

Section 19.4

Return to TOC

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)

(25)

Section 19.4

Return to TOC

Ion Exchange

• _Ca2+ and Mg2+ are often removed during ion

exchange, releasing Na+ into solution.

• _{Ion exchange resin = large molecules with}

(26)

Section 19.4

Return to TOC

(27)

Section 19.4

Return to TOC

End of lesson

• See homework on board.

(28)

Section 19.5

Return to TOC

• Group 3A elements generally show the

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

representative elements.

(29)

Section 19.5

Return to TOC

Aluminum

• Aluminum is easily oxidized:

• Al3+ + 3e-  Al

(s) E ° = -1.66 V

• _{But it resists corrosion due to a surface}

(30)

Section 19.5

Return to TOC

(31)

Section 19.6

Return to TOC

• Contains two of the most important

elements on earth: carbon and silicon.

(32)

Section 19.6

Return to TOC

• Si is easily produced from silica sand (SiO₂).

• SiO_2(s) + 2C_(s)  Si_(s) + 2 CO_(g)

• Contrast SiO₂ with CO₂:

network solid;

(33)

Section 19.6

Return to TOC

(34)

Section 19.6

Return to TOC

(35)

Section 19.7

Return to TOC

• … exhibit varied chemical properties:

(36)

Section 19.8

The Chemistry of Nitrogen

Return to TOC

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)

ΔH° ≈ - 34 kJ

N₂H₄(g)  N₂(g) + 2H₂(g)

(37)

Section 19.8

Return to TOC

Nitrogen reactions

• 3Mg + N₂  Mg₃N₂

• _{The Haber Process:}

(38)

Section 19.8

Return to TOC

Reactions of nitrogen compounds • NH₃ + H₂O  NH₄+ + OH

-K_b = 1.8 x 10-5

• 2NH₃ + NaOCl  N₂H₄ + NaCl + H₂O

• N₂H₄ + H₂O  N₂H₅+ + OH-

weak base K_b = 8.5 x 10-7

• N₂H₄ + 4OH-  N

2 + 4H2O + 4e

-strong reducing agent

(39)

Section 19.8

Return to TOC

Reactions of nitrogen oxides

• NH₄NO_3(s) N₂O_(g) + 2H₂O_(g)

nontoxic, odorless, “laughing gas”

• 2HNO_3(aq)  2NO_2(g) + H₂O_(l) + ½ O₂

• 2NO_(g) + O_2(g)  2NO_2(g)

brown haze of smog

• 2NO₂  N₂O₄

(40)

Section 19.8

Return to TOC

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+

(41)

Section 19.8

Return to TOC

Reactions involving nitric acid

•Concentrated HNO₃ reacts with copper:

•Cu_(s)+ 4H₃O+

(aq) + 2NO3-(aq) 

Cu2+

(42)

Section 19.8

Return to TOC

Nitrogen fixation

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

(43)

Section 19.8

Return to TOC

(44)

Section 19.8

Return to TOC

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

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

Compound

Oxidation state of N

N

2

O

+1

NO

+2

N

2

O

3

+3

NO

2

+4

(45)

Section 19.8

Return to TOC

Reactions of nitric and nitrous acid

• Nitric acid, HNO₃

• Nitrous acid, HNO₂

3 2 2 2

4HNO ( )

l



hv

4NO ( ) + 2H O( ) + O ( )

g

l

g

+

2 2

(46)

Section 19.9

The Chemistry of Phosphorus

Return to TOC

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)

(47)

Section 19.9

Return to TOC

Allotropes of phosphorus

(48)

Section 19.9

Return to TOC

Phosphorus oxyacids

• phosphoric acid, H₃PO₄

• phosphorous acid, H₃PO₃

(49)

Section 19.9

Return to TOC

How is phosphorus obtained?

• 2Ca₃(PO₄)_2(s)+ 10C_(s)+ 6SiO₂ _(s) P_4(g)+ 10CO_(g) + 6CaSiO_3(s)

(50)

Section 19.10

Return to TOC

• 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.

(51)

Section 19.11

The Chemistry of Oxygen

Return to TOC

• 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}

(52)

Section 19.11

The Chemistry of Oxygen

Return to TOC

Ozone

3O

(53)

Section 19.12

The Chemistry of Sulfur

Return to TOC

• _{Sulfur is found in nature both as the free}

(54)

Section 19.12

The Chemistry of Sulfur

Return to TOC

(55)

Section 19.12

Return to TOC

Reactions involving sulfur compounds

• 2ZnS(s) + 3O₂(g)  2ZnO(s) + 2SO₂(g)

(56)

Section 19.12

Return to TOC

Copyright © Cengage Learning. All rights reserved 56

Sulfur oxide reactions

2SO₂(g) + O₂(g)  2SO₃(g)

Colorless, toxic; Choking odor

(57)

Section 19.13

Return to TOC

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

(58)

Section 19.13

Return to TOC

(59)

Section 19.13

Return to TOC

Preparation of hydrogen halides

H₂(g) + X₂(g)  2HX(g)

• _{When dissolved in water, the hydrogen halides}

(60)

Section 19.13

Return to TOC

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}

(61)

Section 19.14

Return to TOC

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]

(62)

Section 19.14

Return to TOC

(63)

Section 19.14

Return to TOC

Concept check

Which of the following groups is the most

reactive?

(64)

Section 19.14

Return to TOC

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

(65)

Section 19.14

Return to TOC

PES – Photoelectron Spectroscopy

• https://www.youtube.com/watch?v=NRIqXeY1R_I • View video at https://www.youtube.com/watch?

v=gyKD6QULa0A

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

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

• Answer questions on worksheet, downloadable at the same site.

Mass Spectroscopy

(66)

Section 19.14

Return to TOC

This is Mg.

(67)

Section 19.1

Return to TOC

(68)

Section 19.14

Return to TOC

End of lesson

(69)

Section 19.13

Return to TOC

Objectives:

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

• Students will know how to name these compounds.

Chapter 21

(70)

Section 19.13

Return to TOC

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

(71)

Section 19.13

Return to TOC

Coordination compound =

Coordination complex (complex ion) +

Chapter 21

Coordination compounds

Counter ion

Transition metal ion [Lewis acid]

Ligand (attached molecules or

(72)

Section 19.13

Return to TOC

Coordination compounds

[Co(NH₃)₅Cl]Cl₂

Chapter 21

Coordination compounds

T.M. ion Ligands Counter ions

Note: Co has an oxidation state of +3.

(73)

Section 19.13

Return to TOC

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

(74)

Section 19.13

Return to TOC

Monodentate ligands

Chapter 21

Ligands

Bidentate ligands

(75)

Section 19.13

Return to TOC

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)

(76)

Section 19.13

Return to TOC

Naming coordination compounds

Chapter 21

Ligands

Try this one:

(77)

Section 19.13

Return to TOC

End of lesson

Chapter 21

Ligands

(78)

Section 19.13

Return to TOC

Objective:

Chapter 22

Organic Compounds

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

Chapter 22

(79)

Section 19.13

Return to TOC

Zumdahl Ch. 22

Organic Chemistry

Chapter 22

(80)

Section 19.13

Return to TOC

Chapter contents

•

Introduction

•

alkanes C

_n

H

_2n+2

–

Isomers

–

Nomenclature

–

Cycloalkanes

C

_n

H

_2n

•

alkenes C

_n

H

_2n

•

alkynes C

_n

H

_2n–2

•

aromatics

(81)

Section 19.13

Return to TOC

Organic

Chemistry

•

It was once believed that organic

chemicals could only arise in living things.

•

In 1828, German chemist Friedrich Wöhler

dispelled that myth:

•

(mineral) ammonium cyanate, NH

₄

CNO,

heated gave (organic) urea, (NH

₂

)CO(NH

₂

).

Chapter 22

(82)

Section 19.13

Return to TOC

Modern Views

•

With the exception of petroleum

products, geological and elemental

carbon is inorganic carbon.

•

Other carbon-containing molecules are

all organic.

•

There are no end to the combinatorial

possibilities since C bonds to C!

Chapter 22

(83)

Section 19.13

Return to TOC

Carbon’s Flexibility

•

sp, sp

2

, sp

3

mean a rich geometry of 180°,

120°, and 109.43° angles in virtually endless

chains and branches of organic molecules.

For example: the

most potent

psychotropic

chemical cocktail

on Earth …

CHOCOLATE!

Chapter 22

(84)

Section 19.13

Return to TOC

Carbon’s reactivity

•

NOT

.

•

With the exception of unsaturated sites

(C-C double or triple bonds), it is at the

heteroatoms (non-CH atoms, X) in an

organic molecule where lies the reactive

site.

•

Common CX combinations are called

functional groups and determine

reactivity.

Chapter 22

(85)

Section 19.13

Return to TOC

Inorganic carbon

•

elemental carbon

–

graphite

–

diamond

–

buckminsterfullerene

•

carbon oxides and halides

•

carbonates and carbides

•

simple cyano- compounds like HCN.

Chapter 22

(86)

Section 19.13

Return to TOC

Alkanes

•

Saturated hydrocarbons, C

_n

H

_2n+2

.

–

“Saturated” because they can’t take any

more hydrogen atoms!

–

Straight chains are H

₃

C–(CH

₂

)

_n–2

–CH

₃

–

Gaseous for n<5; solid for n>17 @ STP.

–

Inert (but for strong oxidizers)

–

Extremely nonpolar.

–

Waxes, oils, & fuel gases as n decreases.

Chapter 22

(87)

Section 19.13

Return to TOC

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

(88)

Section 19.13

Return to TOC

Branching & isomers

•

After n = 3, it’s possible to let some C s

bond with 2 - 4 other carbons.

–

The # of structural isomers possible

thereby grows exponentially with n.

–

These isomers have similar chemical and

physical properties.

–

So they’re expensive to separate, and one

sees bottles labeled merely “hexanes.”

Chapter 22

(89)

Section 19.13

Return to TOC

Isomer naming

•

Older conventions would have that as

“

iso

octane,” but IUPAC names follow these

rules:

–

Name the longest C chain (

pentane

)

–

List the side groups in alphabetical order

with Greek prefixes (

trimethyl

pentane)

–

Supply (smallest possible) positional

indices (

2,2,4

-trimethylpentane)

–

The gasoline power rating standard

molecule.

Chapter 22

(90)

Section 19.13

Return to TOC

Cycloalkanes, C

_n

H

_2n

•

If the two end C’s lose 1 H each, they have

free valence to close a ring; voila,

cyclo(whatever)ane.

–

Again properties similar to straight chains.

–

Can now have conformational isomers!

–

E.g., BOAT cyclohexane versus CHAIR

See the C 3 and S

6 here?

Chapter 22

(91)

Section 19.13

Return to TOC

Alkenes, C_nH_2n

• 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

(92)

Section 19.13

Return to TOC

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-but_ene

cis for the same side

Chapter 22

(93)

Section 19.13

Return to TOC

Alkynes, C_nH_2n–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

(94)

Section 19.13

Return to TOC

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

(95)

Section 19.13

Return to TOC

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

(96)

Section 19.13

Return to TOC

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

(97)

Section 19.13

Return to TOC

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

(98)

Section 19.13

Return to TOC

Carboxylic Acids

R–CO

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

O–H

+  +

butanoic acid

“rancid yak butter”

ethanol ethyl butyrate

“pineapple”

water

Chapter 22

(99)

Section 19.13

Return to TOC

Amines, R_n–NH_3–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 K_b 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

(100)

Section 19.13

Return to TOC

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.