Chem Exam 2 Actual

linear

180 degrees, 2 bonding sets, 0 lone pairs/ 2 bonding sets, 3 lone pairs

trigonal planar

120 degrees, 3 bonding sets, 0 lone pairs

bent

less than 109.5 degrees, 2 bonding sets, 1-2 lone pairs

tetrahedral

109.5 degrees, 4 bonding sets, 0 lone pairs

trigonal pyramidal

around 107 degrees, less than 109.5 degrees but ideal is 109.5, 3 bonding sets, 1 lone pair

trigonal bipyramidal

90 and 120 degrees, 5 bonding sets, 0 lone pairs

seesaw

90 and 120 degrees, 4 bonding sets, 1 lone pair

t-shape

90 degrees, 3 bonding sets, 2 lone pairs

octahedral

90 degrees, 6 bonding sets, 0 lone pairs

square pyramidal

90 degrees, 5 bonding sets, 1 lone pair

square planar

90 degrees, 4 bonding sets, 2 lone pair

average bond order

total bonds/ number of resonance structures

formal charge

valence electrons - lone electrons - bonds

sigma and pi bonds

single - sigma

double - one sigma, one pi

triple - one sigma, two pi

naming polyatomic ions

-ate: more oxygen atoms

-ite: less oxygen atoms

Per- : more oxygen

Hypo: less oxygen

naming binary ionic compound

name of metal cation + parenthesized roman-numeral indicating metal charge , anion base name + ide

naming polyatomic ionic compound

name of metal cation and polyatomic anion name (or oxyanion name)

prefixes for hydrates and polys

1. mono

2. di

3. tri

4. tetra

5. penta

6. hexa

7. hepta 

8. octa

9. nona

10. deca

naming binary molecular compound

1. more metal-like element

2. more nonmettallic element

greek prefix (number of atoms of first element) + first element name then greek prefix + second element -ide

naming binary acid

hydrogen and nonmetal (hydro + nonmetal base name + ic)

naming oxyacid

hydrogen and oxyacid anion (ate: base name + -ic, ite: base name +-ous)

cis isomer

same side

trans isomer

opposite side

enantiometers

isomers that are mirror images of each other but do not super impose

coulumb’s law

lattice energy (delta H= product of ion charges/ distance between atoms

hess’s law

total enthalpy change is a sum of all enthalpy change steps

homonuclear

same element in compound

constitutional isomers

same molecular formula but different atom connectivity

conformational isomers

rotation around single bonds

diastereomers

stereoisomers that are not mirror images of each other, non-identical and non-superimposable

meso compounds

organic molecules with at least two chiral centers, internal plane of symmetry, superimposable, optically inactive