Ch. 3 - Functional Groups Flashcards
Which characteristics do functional groups determine?
electron-deficient sites, acid-base behavior, overall polarity
T or F: A C=C pi bond is easily broken and causes a molecule to be nucleophillic?
true
T/F: A heteroatom acts as a nucleophile and causes carbon to be electron-deficient?
true
Is a C-Z bond polar or non polar?
polar
T/F: pi bonds are hard to break in a reaction?
false, pi bonds are easy to break.
T/F: pi bonds make a molecule nucleophillic?
true, it also causes it to act as a Lewis base
The atom Z has one or more lone pairs of electrons, allowing it to act as both a nucleophile and a _____.
lewis base
T/F: covalent compounds are composed of discrete molecules?
true
What type of interactions hold ionic bonds together?
electrostatic
Solute-solvent interactions must be ____ to solute-solute interactions.
similar
Energy required to break up the interactions between the molecules or ions of a solute comes from new interactions between the __________________.
solute and solvent
Hydrogen bonds are _______ than most covalent bonds.
weaker
What are three important features of the C-H bond?
strong, nonpolar, not readily broken
What is a functional group?
atom or group of atoms with characteristic chemical/physical properties “reactive part”
What does the functional group of a molecule determine?
geometry, physical properties, reactivity
What do heteroatoms and pi bonds determine reactivity?
heteroatoms have lone pairs, create spot of electron deficiency on carbon
pi bonds are easily broken in reactions, pi bonds make molecules that are basic and nucleophillic
What does “R” stand for?
carbon backbone
What are the three types of functional groups?
hydrocarbons, compounds with C-Z bonds, compounds with C=O bonds
What are hydrocarbons?
compounds made of only carbon and hydrogen
What are the two types of hydrocarbons?
aliphatic and aromatic
What are the three types of aliphatic hydrocarbons?
alkanes, alkenes, alkynes
What is an alkane?
has C-C single bond, no functional group
What is an alkene?
has C=C double bond (pi bond as functional group)
What is an alkyne?
has CH triple bond (pi bonds and functional group)
What is an aromatic hydrocarbon?
strong, sweet odor
includes benzene and phenyl groups
How are carbon groups in alkanes and other compounds classified?
number of carbons directly bonded to that carbon
How are hydrogen classified?
type of carbon they are bonded to (1º carbon = 1º H)
What are C-Z functional groups?
carbon is bonded to EN Z atom which creates polar bond
What is the important thing that Z does to C in a C-Z functional group?
makes carbon electron deficient
What is important about the lone pairs on Z in a C-Z functional group?
lone pairs are available for reactions with protons and electrophiles (especially when Z is N or O)
How are amines classified (º)?
by the number of C-N bonds
What is a C=O functional group?
contains carbonyl group (C=O)
What is important about C=O groups?
polar makes carbon electrophile
lone pairs on O allow it to act as a nucleophile/base
contains a pi bond, more easily broken than C-O sigma bond
How are amides classified?
number of carbons bonded to N
What are ionic compounds?
oppositely charged particles held together by extremely strong electrostatic forces
Does it take a lot or a little energy to separate charged ions?
A LOT
What are covalent compounds composed of?
discrete molecules
What holds covalent compounds together?
covalent bonds, IMFs
What causes van der Waals?
momentary changes of electron density/temporary dipoles
What types of molecules have van der Waals?
nonpolar and polar (all)
What determines the strength of van der Waals?
greater surface area = stronger force
larger atoms = more polarizable = stronger IMFs
What is polarizability?
measure of how the electron cloud around atom responds to changes in electronic environment
What causes dipole-dipole interactions?
attractive forces between permanent dipoles of 2 polar molecules
What causes hydrogen bonding?
occurs when H atoms bonded to NOF is electrostatically attracted to a lone pair of an electron on another NOF atom in another molecule
How does IMFs affect boiling point?
stronger IMFs = higher boiling point
How does surface area affect boiling point?
higher surface area = higher BP
How does polarizability affect boiling point?
more polarizable = higher BP
How does IMFs affect melting point?
stronger IMFs = higher MP
How does symmetry affect melting point?
if the same functional group, the more symmetrical molecule will have a higher MP
(why? it packs easier)
Where does energy needed to break interactions between the solute come from?
interactions between solute and solvent
T/F: compounds dissolve in solvents with similar IMFs.
true
Is water a polar/nonpolar solvent?
polar
Are organic compounds polar/nonpolar solvents?
nonpolar
Are most ionic compounds soluble in water or organic solvents?
water, non organic solvents
most organic compounds are soluble in organic solvents
When are organic compounds soluble in water?
if it contains one polar functional group per every 5 carbon atoms
1 polar FG : 5 carbons
How does the size of an organic polar molecule determine solubility?
large molecule with little polar groups = insoluble
What must all functional groups include?
pi bonds or heteroatom
What does an EN heteroatom do?
makes C electrophillic
What do lone pairs on heteroatom do?
makes heteroatom a basic nucleophile
What does an electophile react with?
a nucleophile
