Fundamentals Flashcards
when a molecule has fewer bonds than expected, what is the result?
a negative charge
when a molecule has more bonds than expected, what is the result?
a positive charge
Ex: such is the case with NH4. when nitrogen must share the lone pairs of electrons with one extra hydrogen, the overall molecule will gain a positive charge
what is this molecular shape? in degrees?
linear 180 degrees
what is this molecular shape? in degrees?
trigonal planar 120 degrees
what is this molecular shape? in degrees?
BENT trigonal planar <120 degrees
what is this molecular shape? in degrees?
tetrahedral 109.5 degrees
what is this molecular shape? in degrees?
trigonal pyramidal 107 degrees
what is this molecular shape? in degrees
BENT tetrahedral 104 degrees
identify each of the molecular shapes:
list the electronegativity in order from greatest to weakest of these molecules: Florine, Chlorine, Nitrogen, Oxygen, Hydrogen, and Carbon
list the names of forces between molecules in order from greatest force to least amount of force
Ionic bonds > hydrogen bonds > dipole-dipole forces > London forces
what are London forces based on?
surface area
number of electrons
which has a high surface area vs low?
pentane = high surface area
neopentane = low surface area (think of beach balls touching another beach ball)
how strong are the forces between a compound with a low boiling point?
weak
how strong are the forces between a compound with a high boiling point?
strong (think of metals)
if a compound has many electrons, how strong are the London forces?
strong
if a compound has lesser electrons, how strong are the London forces?
weak
what are dipolar forces?
forces between negatively charged and positively charged ions
what are hydrogen bonds?
bonds of Hydrogen between O, N, or F
what are ionic bonds?
bonds between metals and nonmetals
what is a haloalkane?
an alkane + any halogen
what is an ether?
oxygen separated with two chains of carbon chains
what are thiols?
carbon chain attached to SH
what are sulfides?
sulfur separated with two chains of carbon chains
what are disulfides?
two sulfur connected together and separated by two carbon chains
what are amines?
Nitrogen connected and separated by carbon chains
what are aldehydes?
ketones?
carboxylic acids?
ester?
amide?
Peroxide?
what would this structure be called?
what is the difference between isobutyl, sec-butyl and tert-butyl?
isobutyl has a methyl branch at the second to last carbon of the substi.
sec-butyl has a methyl branch at the first carbon of the substi.
tert-butyl has a trimethyl branch at the first carbon of the substi.
what is the name of this substituent
sec-butyl
what is the name of this substituent?
isobutyl
what is the name of this substituent?
tert-butyl
name this structure
name this structure
what are the factors that contribute to London forces?
surface area
number of electrons
what is the boiling point of a compound dependent on?
intermolecular forces (stronger IMFs = higher boiling point)
number of branches - more branching causes reduction of surface area = lower boiling point
what is the melting point of a compound dependent on?
IMFs
symmetry - more symmetrical molecules will have higher melting points
which molecule would have higher boiling point and which higher melting point?
a.) would have higher boiling point because the net dipole is positive in value (stronger IMFs)
b.) would have a higher melting point because it is more symmetrical (more symmetry)
are alkanes polar or nonpolar? do they dissolve in water?
alkanes are nonpolar
they do not dissolve in water
what are some characteristics of alkanes?
less dense than water
flammable
odorless
colorless
tasteless
nontoxic
what is the definition of a smaller alkane?
1-4 carbons = gas
they are a suffocation hazard
what does the reaction of complete combustion of an alkane require and what does it produce? incomplete?
how many degrees in a trigonal planar?
120
how many degrees in a bent trigonal planar?
118
how many degrees in tetrahedral?
109.5
how many degrees in trigonal pyramidal?
107
how many degrees in bent tetrahedral?
104
which directions along the periodic table is electronegativity stronger?
gets stronger as it moves towards fluorine in the upper righthand corner
which of these would have stronger London forces?
pentane would have stronger forces because it has more surface area
neopentane would have weaker forces because of the low surface area
