Polarity and Solubility Flashcards
Define/draw an alkane group.
C(n)H(n+2)
Differentiate between aliphatic and aromatic hydrocarbon rings.
Aliphatic = no conjugated double bond system Aromatic = conjugated double bond system (among other characteristics; e.g. benzene/phenyl)
Define/draw an alcohol group.
R-OH
Define/draw an ether group.
R-O-R
Define/draw an aldehyde group.
R-COH
Define/draw a ketone group.
R-CO-R
Define/draw a carboxylic acid group.
R-COOH
Define/draw a fatty acid molecule.
R-COOH, usually where R = a long hydrocarbon chain (≥14 C).
Define/draw an ester group.
R-COO-R
Define/draw an amine.
R-NH2
Differentiate between primary, secondary, and tertiary amines.
Primary - N is bound to 1 R group
Secondary - N is bound to 2 R groups
Tertiary - N is bound to 3 R groups
Differentiate between primary, secondary, and tertiary alcohols.
Primary - central C to which OH group is bound is also bonded to 1 R group
Secondary - central C to which OH group is bound is also bonded to 2 R groups
Tertiary - central C to which OH group is bound is also bonded to 3 R groups
Define/draw an amino acid.
H3N-COOH-R
Define/draw an amide.
R-CO-NH2
Differentiate between a primary, secondary, and tertiary amide.
Primary - N is bound to only 1 R group (the R-CO group)
Secondary - N is bound to 2 R groups (including the R-CO group)
Tertiary - N is bound to 3 R groups (including the R-CO group)
What is a polyamide? Give a biologically-relevant example.
Long chain of amides formed by condensation of the amide’s H and a carboxylic acid’s OH; e.g. polypeptides (proteins).
What differentiates chlorophyll a from chlorophyll b?
Chlorophyll a contains a methyl group at the position where chlorophyll b has an aldehyde group.
Describe the 2 main types of intermolecular bonds.
Ionic - electrons are transferred from one element to another to form a cation and anion which balance one another’s charges
Covalent - electrons are shared by elements to give rise to a stable valence shell in both
What chemical characteristic determines whether a bond is ionic or covalent?
Electronegativity of each element in the bond and the difference in EN.
Define electronegativity.
An element’s relative affinity for electrons.
What is polarity?
Asymmetrical distribution of charge within a molecule due to differences in the electronegativity of its component atoms/elements.
Describe the 3 types of polarity that can exist within a bond.
- Nonpolar - no difference in electronegativity between member atoms
- Slightly polar - some difference in EN between member atoms which results in electrons being “held” slightly closer to one atom
- Strongly polar - extreme difference in EN between member atoms which restuls in electrons being transferred completely to the more EN atom (ionic bond)
Define a dipole moment.
Vector describing the direction and magnitude of charge production across a bond or the vector sum of polar bonds within a molecule, which determines areas of positive and negative charge within the molecule.
Define inductive effects.
Removal or addition of electron density by a strongly or weakly EN atom or functional group across sigma (single) bonds.
Describe the 3 main types of intermolecular bonds.
- Ion-dipole bonds - attraction between ions and areas of opposing charge within covalent molecules
- Hydrogen bonds (dipole-dipole) - interaction between H atoms bound to a highly EN central atom and lone electron pairs on the highly EN central atom of another molecule (i.e. O or N)
- van der Waals forces - interaction between temporary dipoles created by distortion of electron clouds as nonpolar molecules near one another
How does distance between functional groups affect induction within a molecule?
Inductive effects exerted by a functional group diminish the further that functional group is from the area of electron density (i.e. functional group) being affected.
