Chemistry

Question 1

atomic mass vs atomic weight

Answer 1

mass is roughly protons + neutrons
weight is the average mass of isotopes (on periodic table)
both in amu units

Question 2

quantum numbers

Answer 2

n, l, ml, ms

describes position + energy of electron in an atom (energy states)

Question 3

n quantum number

Answer 3

• number of shells

- max # of e in a shell = 2n^2

Question 4

l, azimuthal quantum number

Answer 4

• refers to shape and number of subshells
  -possibility of subshells = (n - 1)
  (n=3 can have subshell 0, 1, 2)
  -max number of e in a subshell = 4l + 2
  -s, p, d, f, = examples of subshells

Question 5

ml magnetic quantum number

Answer 5

• refers to the orbital of a subshell

- number of orbitals in a subshell = -l to +l, including 0 (ex. l=1 ml= -1,0,+1)

Question 6

ms spin quantum number

Answer 6

• electrons can spin up or down (half arrows)

- -(1/2) or + (1/2)

Question 7

electron configuration

Answer 7

(read periodic table)

-spdf

Question 8

hunds rule electron configuration

Answer 8

draw out elec. config
in order with electrons starting in lowest to highest orbital
-number of spots = ml of orbital

Question 9

Exceptions to the electron configuration rule

Answer 9

Chromium (Z=24) [Ar] 4s^1d^5

Copper (Z= 29) [Ar] 4s^1 3d^10

Question 10

Metals

Answer 10

middle to left of the periodic table (not Hydrogen), including lanthanides + actinides
(opposite of non-metals)
-easily give up e-, good conductors or heat and E
-low effective nuclear charge
-low electroneg, high electropositivity
-large atomic radius, low ionization energy
-malleable

Question 11

Non-metals

Answer 11

upper right of periodic table

• high electronegativity + ionization E
• small atomic radii
• don’t give up e easily
• poor conductors
• brittle solids

Question 12

Metalloids

Answer 12

stair step group btw metal + nonmetals

-the in between of metals + non-metals

Question 13

effective nuclear charge (Zeff) + periodic table trend

Answer 13

pull of e- to nucleus
-for the most part more e- in valence = more pull (Zeff)
(left to right increasing)
compare directly up and down, up is stronger

Question 14

Atomic radii + periodic table trend

Answer 14

• half the distance between 2 atoms in contact
• decreases left to right (Zeff pulls valence e- in)
• radius increases going down

Question 15

ionic radii + periodic table trend

Answer 15

• nonmetals: gain e- and become more negative
  
  • nonmetals closer to metalloids line have larger ionic radii
• metals: lose e- and become more positive
  
  • metals closer to metalloids are smaller

Question 16

Ionization Energy + periodic trends

Answer 16

• endothermic (requires energy) to removing an e- -greater Zeff, harder to remove e-, increasing ionization E -Increases to right, decreasing down
• increases w/ each ionization

Question 17

electron affinity

Answer 17

• exothermic, gain an e-
• increasing to the right (to complete the octet)
• decreases going down

Question 18

electronegativity

Answer 18

-highest towards F (similar to ionization energy)

_exclude noble gases

Question 19

alkali metals

Answer 19

• +1 charge typically (only 1 valence e-)

Question 20

alkaline earth metals

Answer 20

• +2 charge typically

Question 21

halogens

Answer 21

• 7 valence e-, highly reactive

- often form bond with itself (gas)

Question 22

exceptions to the octet rule

Answer 22

incomplete octet - lass than 8 (H (2), He (2), Be (4), B(6)
expanded - more than 8 (period higher than 3/d orbital)
P(10), S (12), Cl (14)
odd number of e- can’t distribute an e- to give 8 (NO, had 11 e-)

Question 23

Coordinate covalent bond

Answer 23

Lewis acid/base

Question 24

Type of reactions

Answer 24

• Neuralization: type of DD rxn acid + base form a salt and h20
• combination
• decomposition
• combustion: fuel** hydrocarbon + oxidant (typically 02) to get H2O + CO2
• Single displacement: usually a redox
• double displacement: swapping (1 metal +nonmetals)

Question 25

Thin Layer Chromatography

Answer 25

mobile phase = non-polar

stationary phase = polar

Question 26

anion-exchange chromatogtraphy

Cation-exchange

Answer 26

anion: + stationary phase (holds onto negative charges)
cat: - charged stationary phases (holds onto + longer)

Question 27

reverse phase chromatography

Answer 27

mobile phase is polar
stationary phase is np
more polar = elutes faster b/c interacts better w/ mobile

Question 28

optical activity

Answer 28

if molecule has chiral centers

Question 29

UV-vis spectroscopy

Answer 29

to analyze conjugated molecules (double/triple bonds)

Question 30

NMR (downfield vs. upfield)

Answer 30

downfield: left side of the graph, more deshielded (closer to electronegative)
upfield: right of the graph, more shielded (away from electronegative atoms)

Question 31

soluble compounds

Answer 31

Always:
-alkali, NH4, NO3, ClO3, CH3COO
Usually:
-halides (F to I) except w/ Ag, Pb, Hg
-sulfate SO4 except w/ Pb, Ca, Sr, Ba

Question 32

Unsoluble compounds

Answer 32

Always: (unless w/ always soluble)
-CO3, PO4, S, SO3
Usually:
- Hydroxides (-OH) + metal Oxides (except w/ Ca, Sr, Ba)

Question 33

Strong Acids

Answer 33

• HI, HBr, HCl
• HNO3, H2SO4
• HClO3, HClO4

Question 34

Strong Bases

Answer 34

• LiOH, NaOH, KOH, CsOH, CaOH2, SrOH2, BaOH2
• NH2, H-
• CH3O-, CH3CH2O-, (CH3)3CO-