1. Hydrogen Bonding O O Intermolecular forces of attraction between
molecules
(hydrogen bonds)
Bonds exist within
(covalent bonds)
Intermolecular
forces O H
Bonds O H
Bonds
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 442

2. Interaction of Dipoles
(a) Interaction of two
polar molecules.
(b) interaction of many
dipoles in a liquid
- +
- + + -
Attraction
Repulsion
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 442

3. Polar Water Molecule d + O 2d - d + H H
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 443

4. Hydrogen Bonding among water Molecules

5. Hydrogen Bonding among water Molecules
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 443

6. Boiling Points of Covalent Hydrides3 He 2 C 6 N 7 O 8 F 9 Ne 10 Na 11 B 5 Be 4 H 1 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 Cs 55 Ba 56 Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 Fr 87 Ra 88 Rf
104 Db
105 Sg
106 Bh
107 Hs
108 Mt
109 Mg 12 *
Boiling Points of Covalent Hydrides
H2O
100
Hydrogen Bonding
H2Te
Boiling point (oC)
H2Se
H2S
-100
-200 2 3 4 5
Period of X (H2X)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 443

7. Boiling Points of Covalent Hydrides
H2O
100
H2Te
Boiling point (oC)
H2Se
SnH4
H2S
-100
GeH4
SiH4
CH4
-200 50
100
150
Molecular mass

8. Heating / Cooling Curve of Water
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 445

9. Water Molecules in Liquid and Steam
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 446

10. Microscopic view of a liquid near its surface
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 449

11. Behavior of a liquid in a closed container
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 450

12. Water rapidly boiling on a stove

13. Formation of a bubble is opposed by the pressure of the atmosphere
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 452

14. Boiling Points of Covalent Hydrides
H2O
100
H2Te
Boiling point (oC)
H2Se
H2S
-100
-200 2 3 4 5
Period of X (H2X)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 443

15. Boiling Points of Covalent Hydrides3 He 2 C 6 N 7 O 8 F 9 Ne 10 Na 11 B 5 Be 4 H 1 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 Cs 55 Ba 56 Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 Fr 87 Ra 88 Rf
104 Db
105 Sg
106 Bh
107 Hs
108 Mt
109 Mg 12 *
Boiling Points of Covalent Hydrides
H2O
100
H2Te
Boiling point (oC)
H2Se
H2S
-100
-200 2 3 4 5
Period of X (H2X)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 443

16. Boiling Points of Covalent Hydrides3 He 2 C 6 N 7 O 8 F 9 Ne 10 Na 11 B 5 Be 4 H 1 Al 13 Si 14 P 15 S 16 Cl 17 Ar 18 K 19 Ca 20 Sc 21 Ti 22 V 23 Cr 24 Mn 25 Fe 26 Co 27 Ni 28 Cu 29 Zn 30 Ga 31 Ge 32 As 33 Se 34 Br 35 Kr 36 Rb 37 Sr 38 Y 39 Zr 40 Nb 41 Mo 42 Tc 43 Ru 44 Rh 45 Pd 46 Ag 47 Cd 48 In 49 Sn 50 Sb 51 Te 52 I 53 Xe 54 Cs 55 Ba 56 Hf 72 Ta 73 W 74 Re 75 Os 76 Ir 77 Pt 78 Au 79 Hg 80 Tl 81 Pb 82 Bi 83 Po 84 At 85 Rn 86 Fr 87 Ra 88 Rf
104 Db
105 Sg
106 Bh
107 Hs
108 Mt
109 Mg 12 *
Boiling Points of Covalent Hydrides
H2O
100
Hydrogen Bonding
H2Te
Boiling point (oC)
H2Se
H2S
-100
-200 2 3 4 5
Period of X (H2X)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 443

17. Boiling Points of Covalent Hydrides
H2O
100
H2Te
Boiling point (oC)
H2Se
SnH4
H2S
Group 16 Hydrogen Compounds
Compound Molar Mass Melting Point Boiling Point H fusion H vapor
(oC) (oC) (cal/mol) (cal/mol)
H2O
H2S
H2Se
H2Te
-100
GeH4
SiH4
CH4
-200 50
100
150
Molecular mass

18. Group16 Hydrogen Compounds
Molar Mass
Melting Point (oC)
Boiling Point (oC)
H fusion
(cal/mol)
H vapor
H2O 18
0.0
100.0
1440
9720
H2S 34
-85.5
-60.7
568
4450
H2Se 81
-60.4
-41.5
899
4620
H2Te
130
-48.9
-2.2
1670
5570
Group 16 Hydrogen Compounds
Compound Molar Mass Melting Point Boiling Point H fusion H vapor
(oC) (oC) (cal/mol) (cal/mol)
H2O
H2S
H2Se
H2Te

19. Ethanol is Polar d - O d + Polar bond C C H H H H H H
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 469

20. Ethanol and Water are SolubleC
‘Like dissolves like’
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 469

21. Molecular Structure of Ice
Hydrogen
bonding
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 455

22. Sodium Chloride Crystal
Formula Unit – simplest ratio of atoms in a compound.
Solid crystals for a lattice structure (repeating pattern) arrangement of atoms.
A single grain of table salt (NaCl) is composed of billions of atoms of sodium and chlorine in a fixed ratio 1:1
= Cl-
= Na+
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 455

23. Packing of NaCl Ions = Cl1- = Na1+
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 456

24. Packing of NaCl Ions
Electron Microscope
Photograph of NaCl

25. Dissolving of Salt in Water
Na+
ions
Water molecules
Cl-
ions
When sodium chloride crystals are dissolved in water, the polar water molecules exert attracting forces which weaken the ionic bonds. The process of solution occurs the ions of sodium and chloride become hydrated.
NaCl(s) + H2O  Na+(aq) + Cl-(aq)

26. Dissolving of NaCl - - - O + + + + Cl- Na+ hydrated ions H
Timberlake, Chemistry 7th Edition, page 287

27. An alloy is a homogeneous mixture of metals.
Brass = Copper + Zinc
Solid brass
homogeneous mixture
Solid Brass
Consumer Tip
Pay attention to labels when purchasing brass. Brass is sold with the label ‘Brass’ or ‘Solid Brass’.
‘Brass’ means brass coated – the object is not ‘solid brass’. It is likely inexpensive, cheap zinc in the center and has only a thin coating of brass on the outside.
Toilet bowl seat screws are often sold as ‘brass’ ($1.29) or ‘solid brass’ ($1.99).
Pay more, the ‘brass’ screw may snap off as zinc is a brittle metal under stress.
‘Solid brass’ is stronger and the better value.
Copper
Zinc

28. Brass Plated Brass = Copper + Zinc Brass plated heterogeneous mixture
Only brass on outside
Brass Plated
Copper
Zinc

29. Hardened Steel Steel Iron Carbon
Carbon is added to steel to make it harder. The addition of too much carbon makes steel very strong, but brittle. A bridge made this way would not sag when stressed, but would snap when too much pressure was applied. Engineers figure the optimal amount of carbon to add to make steel strong, but not too brittle.
Look for link: Steel
Steel
Iron
Carbon

30. Gold 24 karat gold 18 karat gold 14 karat gold 24/24 atoms Au
Copper
Silver
24 karat gold karat gold karat gold
Pure gold (24 karat) is too soft (malleable) for use in jewelry. An alloy is made with copper or silver to make the gold harder and more durable. 14 karat gold means if you take 24 atoms out of the sample 14 will be gold atoms and the remaining 10 atoms another metal.
Many years ago, coins were made from pure silver and pure gold. Dishonest people would shave off the edges of the coins to steal a small amount of silver or gold. Ridges were added to coins to stop people from shaving the coins.
Emphasize that alloys are solutions or mixtures of metals. An alloy’s characteristics differ from those of the metals that compose it.
How are the silver atoms arranged in the14-karat gold?
(They are evenly dispersed among the gold atoms.)
If you were to melt the ring, how would the silver atoms be arranged in the solution?
(They would be evenly dispersed.)
Can an alloy be composed of more than two different metals?
(yes)
24/24 atoms Au
18/24 atoms Au
14/24 atoms Au

31. AgNO3(aq) + KCl(aq)  KNO3 (aq) + AgCl(s)?
Precipitation Reaction Between
AgNO3 and KCl K+
NO3-
AgCl
AgNO3(aq) + KCl(aq)
unknown white solid
Ag+ + NO K+ + Cl-
in silver
nitrate
solution
in potassium
chloride
unknown white solid
Ag+
Cl-
Ag+ + NO K+ + Cl-
Ag+ + Cl K+ + NO3-
product
AgCl precipitate
AgNO3(aq) + KCl(aq) AgCl(s) KNO3(aq)
AgNO3(aq) + KCl(aq)  KNO3 (aq) + AgCl(s)

32. Formation of a solid AgCl
AgNO3(aq) + KCl(aq)  KNO3 (aq) + AgCl(s)
Zumdahl, Zumdahl, DeCoste, World of Chemistry 2002, page 220