chm2046 aleks initial knowledge check

amino group

N bonded to 2 H’s (NH2), N has a lone pair

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p3

or

[Kr] 4d10 5s2 5p4

rule: 4s2 orbital is slightly lower in energy level than 3d so 4s2 fills first

4s → 3d → 4p

ideal gas law (PV=nRT)

P:

V:

n: mol

R:

T: temperature in Kelvin

atomic trends

increases across a period:

• effective nuclear charge (Z)

• ionization energy

decreases across a period:

• atomic radius

  • b/c stronger nuclear charge pulls atom in tighter

polar vs nonpolar (molecule)

polar:

• atoms with different electronegativities

• nonsymmetrical; shapes like trigonal planar or bent (H2O)

• lone pairs

• different outer atoms surrounding central atom

• atom closest to the negative side is the more electronegative atom

nonpolar:

• same atoms

• symmetrical

• pulls cancel

electronegativity difference

• 0: nonpolar covalent

• .4-1.7: polar covalent

• 1.7+: ionic

solubility rules

always soluble:

• group 1 (far left)

• nh4+

• no3-

• c2h3o2-

usually soluble:

• cl-, br-, i-

• so4 2-

usually insoluble:

• co3 2-

• po4 3-

• oh-

• s2-

like dissolves like

name each of these acids

hno2

hno3

hbr

h2co3

hno2: nitrous acid

hno3: nitric acid

hbr: hydrobromic acid

h2co3: carbonic acid

orbital shapes

s orbital

• symmetric

• single sphere around nucleus, NOT ellipse

p orbital

• two lobes separated by a nodal plane (dumbbell shape)

pH and pOH

at 25 degrees C pH+pOH = 14.00

how to see if something’s at equilibrium (q and k)

k is given

q = (# product molecules)/(# reactant molecules)