Chemistry Midterm Review

Front 1

Separates mixtures based on density

Back 1

centrifuge

Front 2

heat of fusion

Back 2

the amt energy required to melt a substance and the amt energy released when substance freezed

Front 3

heat of vaporization

Back 3

the amt energy required to vaporize liquid at its boiling point or condense it

Front 4

sublimation

Back 4

solid to gas

Front 5

entropy

What phase has the most entropy?

Does entropy change when solid to a solution?

Back 5

randomness

gas

a solution has more entropy than its solid counterpart
Ex: NaCl(s) to NaCl (aq)

Front 6

When do liquids boil?

Back 6

when vapor pressure of liquid is equal to atmospheric pressure

Front 7

Ideal Gases (7)

What kind of gases behave most ideally?

Back 7

-particles travel in random, straight-line motion
-particles have no attractive forces
-no change in energy during collisions
-volume doesn't matter
-high temp
-low pressure

smaller molecule gases

Front 8

Kelvin conversion

Back 8

273 + C = K

Front 9

1 mole of any gas at STP

Back 9

22.4 L

Front 10

What is the relation between weight of a gas and the rate of diffusion?

Back 10

Lighter gases (fewer moles) diffuse faster

Front 11

Dalton

Back 11

said atom is a solid sphere

Front 12

Thompson

Back 12

said atoms have pos/neg particles randomly arranged

Front 13

Rutherford (3)

Back 13

Gold Foil Experiment: shot postive alpha particles at gold foil, most went through

-protons in a small nucleus
-electrons outside nucleus
-most of an atom empty space

Front 14

Bohr

Back 14

Electrons in concentric rings

Front 15

Electrons found in orbital clouds according to this model (3 names)

Back 15

Wave Mechanical
Quantum Mechanical
Oribital

Front 16

How much do protons, neutrons, and electrons weigh?

Back 16

proton- 1 a.m.u.
neutron-1 a.m.u.
electron- 0 or 1/1836 of a proton

Front 17

What is the charge of the nucleus?

Back 17

postive

Front 18

What owns all of the mass of an atom?

Back 18

nucleus

Front 19

What is the nuclear charge of an atom?

Back 19

the atomic #, the # protons

Front 20

isotope

Back 20

diff # neutrons, diff mass # (sum of protons+neutrons)

Front 21

atomic mass

Back 21

weighted average of naturally occuring isotopes

Front 22

spectral line patterns

Back 22

unique pattern of bright lines representing specific wavelengths
-no two elements have same pattern
-caused by excited electrons move from higher energy level to ground state

Front 23

artificial tran wsmutation

Back 23

changing one element into another (look for 2 reactants in nuclear equation)

Front 24

An elements is stable if...

Back 24

#protons=#neutrons

Front 25

fission vs. fusion

Back 25

fission: splitting large nucleus which releases energy (bang element w/ neutron)

fusion: joing small nuclei in to large nuclei which releases energy (H+H)

Front 26

Forming vs. breaking bonds

Back 26

Forming: exothermic, releases energy, elements more stable

Breaking: endothermic, absorbs energy, elements less stable

Front 27

Ionic Bonds

Back 27

transfer of electrons from one element to another resulting in ions being formed

Front 28

Covalent Bonds

(polar vs. nonpolar)

Back 28

sharing electrons between 2 nonmetals, form molecules

Nonpolar: even electron sharing between 2 identical nonmetals (diatomic)

Polar:2 diff nonmetals bonded share electrons unevenly

Front 29

Metallic bonds

Back 29

metals bonded

"positive nuclei emmersed in a sea of mobile electrons"
-explains why metals conduct e- well
-conduct heat well
-are malleable and ductile

Front 30

London Dispersion Forces

Back 30

weakest attraction between nonpolar, symmetrical shaped molecules and the noble gases

(larger and molecules that are closer together increase attraction)

Front 31

Dipole-Dipole Attraction

(strongest kind)

Back 31

stronger attraction than LDF between 2 polar shaped molecules

Hydrogen Bonding: strongest dipole attraction between H (+) and N, O, and F (- elements w/ highest electronegativity)

Front 32

What explains the high boiling pt. of water?

Back 32

Hydrogen Bonding

Water molecules are so attracted to eachother it is hard to separate them

Front 33

Molecule-ion attraction

(What does this explain)

Back 33

strongest intermolecular attraction, between polar shaped molecule and ion

Explains how NaCl dissolves in H2O: positive H attracted to negative Cl, positive Na attracted to negative O

Front 34

binary compound vs. ternary compound

Back 34

compound of 2 elements

compound of 2 element

Front 35

Which gas has more molecules?

How many moles in Ne at 273 K, 2 atm, and 22.4 L?

Back 35

22.4 L at 1 atm or 22.4 L at 2 atm

2 moles

Front 36

Uranium-238 and Lead-206

Back 36

used for mineral dating

Front 37

Technetium-99 (Tc)

Back 37

tumor tracer

Front 38

Iodine-131

Back 38

thyroid cancer radiation

Front 39

Carbon-14 and Carbon-12

Back 39

fossil dating

Front 40

When do you have to use Kelvin?

Back 40

Combined gas law

Front 41

Calculate the weighted average of Carbon 13 and Carbon 12. 73% is Carbon 13 and 27% is Carbon 12

Back 41

(.73x13)+(.27x12)=12.73

Front 42

Complete the equation
___ --> 0 60
-1 e + 28 Ni

Back 42

60
27 Co

Front 43

Lewis Dots for Ca, C, and N

Back 43

xx
Ca

x
x C x
x

xx
x N x
x

Front 44

How many sigfigs?
0.00640
120.
120.0
1000

1.0+1.25=

1.0x2.50=

Back 44

3
3
4
1

1.3

2.5