Chem exam 4

Question 1

N atoms

Answer 1

Will always have a lone pari if it has 3 bonds

Question 2

Sigma bonds

Answer 2

Head on
Single: 1
Double: 1
Triple: 1

Question 3

Pi bonds

Answer 3

Overlapping of P orbitals
Single: 0
Double: 1
Triple: 2

Question 4

Hybridization orbitals

Answer 4

Sp: 2 electron domain
Sp2: 3 electron domains
Sp3: 4 electron domains
Sp3d: 5 electron domains
Sp3d2: 6 electron domains

Question 5

Valence bond theory

Answer 5

-Valence electrons reside in quantum mechanical atomic orbitals. They can be S P D F or hybridized combinations of these
-A chemical bond results from the overlap of these 2 half filled orbitals and spin pairing
-The geometry of the overlapping orbitals determines the shape of the molecule

Question 6

Melting points

Answer 6

Stronger= higher

Question 7

Boiling points

Answer 7

Stronger= higher

Question 8

Vapor pressure

Answer 8

Stronger=lower

Question 9

Viscosity

Answer 9

Stronger= higher

Question 10

Surface tension

Answer 10

Stronger = higher

Question 11

Boiling point physical phase

Answer 11

If boiled before 295 = gas

Question 12

Boiling point definition

Answer 12

Temperature at which the liquids vapor pressure equals the external pressure

Question 13

Bond polarity

Answer 13

Caused by differences in electronegativity of elements

Question 14

Molecule polarity

Answer 14

requires bond dipoles, but also has geometric considerations

Question 15

Dipole moment

Answer 15

-Bigger electrongativety difference =bigger dipole moment
-Farther apart = bigger dipole moment
-Tells how big the difference is

Question 16

Net dipole moment

Answer 16

-Overall dipole moment of a molecule
-Sum of individual bond dipoles
-Vector

Question 17

Dipole-Dipole interactions

Answer 17

-Polar
-Permanent dipole moment
-Asymmetric
-Stronger when molecules are closer and bigger difference in electronegativity

Question 18

Dispersion interactions

Answer 18

-Instant non permanent
-in everything
-constant motion
-can be temporarily asymmetric
-creates instantaneous dipole moment
-Bigger molecules = stronger dispersion forces ( more e = larger charges)

Question 19

Ion dipole forces

Answer 19

-ions and a polar molecule interacting
-Full charge atoms
-Ion dipole must compete with ion-ion to get salts to dissolve

Question 20

Hydrogen Bonding

Answer 20

-Lone pairs
-On O, N, F sometimes Cl
-H atom
-Bonded to another electronegative atom

Question 21

H bond acceptor

Answer 21

Lone pairs are connected

Question 22

H bond donor

Answer 22

The one with H

Question 23

Covalent naming

Answer 23

1- mono
2- di
3- tri
4- tetra
5- penta
6- hexa
7- hepta
8- octa
9- nona
10- deca

Question 24

How many moles of (element) are in ___ moles of (compound)

Answer 24

Atoms of element * moles they want

Question 25

Things that make something more polar

Answer 25

-Mainly Larger electronegativity difference -How much dipoles don't cancel out

Question 26

Coulombs law permanent dipoles

Answer 26

-Larger electronegativity, stronger -Closer distance, less strong

Question 27

Coulombs law instantaneous dipoles

Answer 27

-Larger molecules, bigger dipoles, stronger attraction -Closer molecules, stronger (smaller molecules can be closer together)

Question 28

Dipole induced dipole

Answer 28

-Polar permanent dipole with non polar molecule

Question 29

Miscible

Answer 29

-Forming a homogenous solution -Like with like -More polar with non polar= less miscible

Question 30

Vaporization

Answer 30

-Liquid to gas -Endothermic

Question 31

Condensation

Answer 31

-Gas to Liquid -Exothermic

Question 32

Melting

Answer 32

Solid to liquid -Endothermic

Question 33

Freezing

Answer 33

-Liquid to solid -Exothermic

Question 34

Larger delta H

Answer 34

-Stronger interactions

Question 35

C-C bond

Answer 35

350kJ

Question 36

acetone

Answer 36

C3H6O

Question 37

Methanol

Answer 37

CH3OH

Question 38

Ethanol

Answer 38

C2H6O

Question 39

Heating curve of water

Answer 39

1. Ice warming 2. Ice melting to liquid 3. Liquid water warming 4. Liquid water vaporizing 5. steam warming

Question 40

J for water and ice

Answer 40

Water: 4.184 J Ice: 2.09 J