C/OC Flashcards
How does acid make a good leaving group?
Protonates hydroxyl into positive H2O which can then take the electrons from broken bond and leave
Glyceraldehyde structure
Glyceraldehyde is an aldose that can be derived from the oxidation of glycerol;
it contains an aldehyde and two hydroxyl groups
Wedge dash to chair rules
ccw and clockwise matters
wedge is up
dash is down
Imide?
Nitrogen attached to 2 carbonyl groups
Sn2 and Sn1 products, focus on..
Steric hindrance of carbons, LG quality, aprotic + protic solvents, stereochemistry or racemic mixture
IN H bond, what does the h bond acceptor need to be?
EN, small, so N O and F
Coordinate bond requires?
Metal cation and electron PAIR donor
Coordination #?
ligands bound
Zeff equation?
nuc charge - core electrons
Does q or d matter more in determining p=qd?
q
Identical chemical species must have what 3 things?
- elemental composition
- same number of electrons
- same orbital bonding configuration.
Unknown sample ..percentages and mass is given, how do you calculate the atomic weight?
Multiply percent given as decimal by mass, add
Although constant, the equilibrium concentrations are ____ because equilibrium refers to a state of equal ____ (ie, changes in concentration over time)
not equal; reaction rate
How is the solubility of salts affected by pH of solution?
Changing the pH of a solution can enhance the solubility of salts that have an acidic or basic ion. This occurs by applying Le Châtelier’s principle to disrupt the solubility equilibrium and shift the reaction toward the products.
sp3-,sp2-, and sp-hybridized atoms have bond angles of \_\_, \_\_, and \_\_\_ water molecule (H2O) displays a bond angle of \_\_\_ due to increased electron repulsion of its lone pairs
109.5°, 120°, and 180°…104.5
Air bubbles and boiling chips do what?
Air bubbles and boiling chips
- break surface tension
- prevent superheating and bumping
In gas chromatography, the adsorbant is
Polar
GC trace measures retention time, first peaks will be for either _____ or _____ thing (adsorbent is polar)
Most non polar; lowest BP
Signal intensity of a mass spectrometry peak corresponds to the _______ at a given mass-to-charge ratio m/z
relative quantity of ions
ions with smaller m/q ratio are ___ affected by magnetic field and will have a _____ radius of curvature
less affected; larger radius of curvature
Stereospecific:
Rxn produces _________
Stereochemistry of the ________ controls the outcome of the reaction (Z or E / cis or trans)
1 product over other
reactants
BP and pressure (VP) relationship
BP goes up with more pressure (more vapor pressure)
The boiling point temperature is the temperature at which the vapor pressure is equal to _______ pressure.
ambient
Red litmus turns ___ in base
blue
An acid differs from its conjugate base only by the presence of an _____
additional H+
What happens to water as a reactant when weak base/acid dissociate
stays constant
Weak acid is _____ likely to dissociate then charged ion
more
Buffer solution is a ____ acid or base and its conjugate salt
Do changes in PH affect it?
weak; No ph=pka
Amphiprotic ion/compound?
can act as base or acid by accepting or losing hydrogen proton,
usually have negative charge and one or more H+
if full compound and not ion, try to imagine it dissolved and work with its substituent ions, i.e. NaHCO3 –> Na+ + HCO3 , HCO3 can be CO3- or H2CO3
Will HCL react with NH3?
HCL will readily react with weak base NH3 to make NH4Cl
NH3 + H20 –> ?
NH3 + water –> NH4+ and OH-
Element will give color if electrons _____ light and ____ energy levels
absorb; elevate
How can you tell the acidity of an acid from its conjugate base?
Acids are more acidic when conjugate base is more stable by lets say H bonding
Does distilled water at pH 7 affect ionization?
Naw
Can neutralization reactions affect solubility?
Acid-base neutralization reactions can be used to increase the amount of an acidic (or basic) solute that will dissolve in a solvent by forming more soluble ionic salts
If something cannot be metabolized =
no energy = no calories
Ketones and aldehydes of the same MW have _____ boiling points because they both have ______ interactions.
similar; dipole dipole
oxidizing reagent pyridinium chlorochromate (PCC) cannot oxidize aldehydes because it lacks the _____ needed to form the _____ intermediate
water; hydrate
Decarboxylation reaction is?
Decarboxylation is a reaction that removes a carboxyl group from a carboxylic acid with a β-carbonyl, releasing the carboxyl group as CO2 gas
The ester oxygen bonded to both the carbonyl carbon and the alkyl group originates from the ____
alcohol , aka original O from COOH is gone
In retro-aldol reaction:
When heated and treated with ____the carbon-carbon bond between the _____carbons is broken
Base; α- and β-;
In retro aldol reactions:
Products can be ______, or one of each, depending on the substituents on the carbonyl carbon and the β-carbon.
Aldehydes form if the carbonyl and/or β-carbon has _____ substituents, whereas ketones form if all substituents are ______.
forming two ketones or two aldehydes; hydrogen; carbon chains
Aldol shortcut, describe how the product looks
(1a) attacking carbonyl will also contain (1b) alpha carbon, (2) other carbonyl will be attacked
Acetylation?
addition of carbonyl with methly group
Roles of α,b-unsaturated ketone
electrophile in michael addition
nucleophile in aldol condensation
Michael addition
enolate attacks a α,b-unsaturated carbonyl and creates a bond
1. 1,4 addition 2. protonation
Enolate
deprotonation of alpha carbon by strong base
Stability is related to
neg charge, conjugation, EWG
Most acidic group has ____ stable base
most
How to increase solubility of COOH
The solubility of carboxylic acids in water increases when they are converted into carboxylate anions by a base.
Organic compounds with acidic or basic functional groups enter the aqueous layer as ______ when acids and bases are added to an extraction.
Ionic salts
Amines are weak bases that require _____acids to be protonated.
Phenols are weak acids that are only deprotonated by _____ bases.
STRONG - weak acids and bases need strong acids and bases to be deprotonated/protonates
Aliphatic
Aliphatic are nonaromatic, may be cyclic
π stacking
involves interactions between interactive rings which contain Pi bonds
disulphide bonds are_____, result from ______ of cysteine residues
covalent; oxidation
reducing agents break disulphide bonds
Phosphate links to ___ most commonly
-OH
What happens when alcohols like T or S get phosphorylated?
When an amino acid like T or S , which is normally uncharged, gets phosphorylated, it has a negative charge on it then , PAY ATTENTION TO PHOSPHORYLATION
When does a protein aggregate?
protein aggregates when ES forces are neutral on side chains
Oxygen in backbone has ____ charge, full in ____ side chain
partial negative; aspartate
All amino acids have at least two pKa values.
pKa1 is the pKa of the carboxyl group and is usually around __
pKa2 is the pKa of the amino group and is usually around ____
2
9-10
Cyanohydrin?
middle C attached to C≡N and OH
C-N bond in the amide has _____ character
partial double bond, due to electrons on N
How many OH needed in saponification rxn?
One hydroxide ion is required to hydrolyze one ester linkage of a triacylglycerol molecule 🡪 three equivalents of sodium hydroxide will be needed to completely saponify the triacylglycerol
In a concentration cell, the anode and the cathode are both made of the ___ and are surrounded by the ____ but the solutions differ in concentration, which produces a flow of electrons caused by the drive to equalize the ion concentrations in the two half-cells.
Electrons migrate from the anode (placed in a solution with ____ cations) to the cathode (placed in a solution with _____ cations) until the concentrations are equal.
same metal and same ionic solution
fewer cations in anode, more cations in cathode
thermodynamics is ____ of products; kinetics is _____ product formation (activity is kinetics)
stability; rate of
calorimetry is ___ and ___
slow and localized
For a thermodynamic mixture of isomeric products, the relative mole ratio of products is directly related to the relative _____ of these products
stability
How does equilibrium affect product formation?
The AMOUNT of product formed in a reaction is dependent on the equilibrium constant of the reaction. This constant is not changed by a catalyst, which only changes the RATE at which equilibrium is achieved
How to tell thermo stability from products?
relative thermodynamic stability of isomers can be determined based on the amount of heat produced when the compounds are combusted; less heat, greater stability
-H (negative enthalpy) means?
heat released, Temp increased
Alkane/kene/kyne formula eqns
CnH2n+2 – alkane
CnH2n – alkene
CnH2n-2 – alkyne
Pyrrole
N based ring
Porphyrin?
The basic unit of a porphyrin is the pyrrole ring, a five-sided heterocycle containing one nitrogen atom
eg heme
wedge dash to haworth
wedge = UP, dash = DOWN, cis trans is maintained here
To be classified as aromatic, a compound must have:
Conjugated pi bonds in a cyclic structure
Unhybridized p orbitals present in each atom in the ring
Planar geometry
Phosphatide -
Basically phospholipid (2 FA esters, phosphate and maybe nitrogen )
Conjugated systems and colors
Relationship between conjugation and wavelength?
With every double bond added, the system absorbs photons of LONGER wavelength
B lactam reactivity compared to non cyclic amides is due to?
β-lactams are a class of cyclic amides
exhibit significant ring strain due to their small ring size, making the carbonyl carbon more reactive than noncyclic amides.
The nitrogen atom in a β-lactam is trigonal pyramidal rather than planar and has decreased resonance. Unlike noncyclic amides, this nitrogen is sp3 hybridized and substantially more reactive.
When numbering a cyclic molecule in this case a nitrogenous base, number so N’s are ____ #
lowest #
How do alkyl groups affect reactivity of carbocations and anions?
the alkyl groups help stabilize carbocations but destabilize carbanions.
Therefore, the order of decreasing stability for these species is:
Carbocation: tertiary > secondary > primary > methyl
Carbanion: methyl > primary > secondary > tertiary
Describe how to read an amino acid titration curve?
Pka of acid group, base group, and R group (lowest to greatest)
Pka is found at the buffer regions (flat) where pH = pKa
SDS page, everything has a _____ charge
negative, the more something moves to the cathode, the smaller is it
Liposones and fluroescent dye?
trap is so cannot fluroesce, liposomes break in size exclusion
X rays and slit diffraction?
cannot undergo regular slit diffraction but sometimes may diffract when exposed to certain crystallized materials
Law of mass action
The law of mass action states that the rate of a reaction is proportional to the molar amount of each reaction component raised to the power of its coefficient that occurs in the chemical equation
basically Eq formula..?
Thermal conductivity (k) relationship to Heat flow (H)?
Proportional
Isotopes of the same element have nearly identical _____properties but differ in their _____ properties.
chemical; physical
valence electrons drive chem activity
What are representative elements?
The representative elements (main group elements) are the elements in Groups 1–2 (1A–2A) and Groups 13–18 (3A–8A) that are contained in the s-block and the p-block, respectively, of the periodic table.
Buffers consist of a mixture of
either a weak acid and a salt of its conjugate base, or a weak base and a salt of its conjugate acid.
How is hydrophobic character determined?
Check how many CH bonds
inverse proportion graph shape
CURVED
1 faraday is equal to
charge in 1 mole e = aka 10^5
Sigma bonds are ______ than π bonds.
energy, stability, dissociation E
lower in energy, more stable, and have a greater dissociation energy
In Ksp and Keq eqns, what do you fo with the coefficients?
ADD IN CONC BRCKET AND AS EXPONENT BITCh
The Henderson-Hasselbalch equation relates what?
the pH, pKa, and the concentration ratio of the acid and conjugate base.
What is kinetic control?
reaction is irreversible (eg, low temperature)
most favorable product is the one whose pathway has the lowest Ea
How does nucleophilicity compare when all molecules have same charge?
When comparing the nucleophilicity of atoms of equal negative charge, nucleophilicity tends to increase from right to left across a row of the periodic table as electronegativity decreases. Atoms of higher electronegativity more effectively stabilize negative charge and less readily donate electron density to electrophiles whereas those of lower electronegativity stabilize a negative charge less effectively and more readily donate electrons to electrophiles.
Cyclic anhydride is attacked by an alcohol or amine, what happens?
Ring opens, ester or amide is formed, respectively
most acidic hydrogens (most to least) and factors that affect acidity
alcohol –> a hydrogen –> sp2 H –> sp3 H
- neg charge on EN atom
- resonance
min relative speed is when two things are moving in the ___ direction
same
A linear polarization filter blocks ____ aligned perpendicular to the axis of polarization
A linear polarization filter blocks electric fields aligned perpendicular to the axis of polarization
Ohms law relates __ voltage to resistance
lost
MA eqns
Fo/Fi = di/do
Light with higher frequency (such as violet light compared to red light) has a ____ index of refraction in a lens and therefore ____ more.
Light with higher frequency (such as violet light compared to red light) has a higher index of refraction in a lens and therefore refracts more.
The formation of blurry images due to dispersion is known as _____
The formation of blurry images due to dispersion is known as chromatic aberration.
The ratio of the image height to the object height is equal to the ratio of their respective ____.
The ratio of the image height to the object height is equal to the ratio of their respective distances.
secondary alpha hydrogen makes the ____ product in aldol condensation
thermodynamic
when 2ndary amine attacks carbonyl what froms and why
enamine, bc amine cannot be deprotonated during last step so its alpha hydrogen is
Lots of intramolecular H bonding affect on BP and polarity
both decreased
the presence of impurities in a compound ____and broadens the melting point range
the presence of impurities in a compound lowers and broadens the melting point range
eluting strength of a solvent is primarily related to how strongly it ____
eluting strength of a solvent is primarily related to how strongly it adsorbs onto the adsorbent
Ultraviolet (UV) light, which corresponds to wavelengths between _____,
Ultraviolet (UV) light, which corresponds to wavelengths between 200 nm and 400 nm,
π* antibonding orbital
Upon interactions with UV light of sufficient energy, π and nonbonding electrons are excited to the Lowest Unoccupied Molecular Orbital (LUMO), called the π* antibonding orbital. These excitations are described as a transition from the lower energy bonding molecular orbital to the higher energy antibonding orbital in the form of π –> π* or n –> π*, depending on whether a π or n electron is excited.
Modifying a molecule’s _____ or _____ changes its affinity for the organic or aqueous layer.
Modifying a molecule’s charge or polarity changes its affinity for the organic or aqueous layer.
Decarboxylation is a reaction that
Decarboxylation is a reaction that removes a carboxyl group from a carboxylic acid with a β-carbonyl, releasing the carboxyl group as CO2 gas.
if lowest priority is wedged, is clockwise S or R
SSSSSSSSSSS
If a compound has Cysteine residues (-SH groups) and is oxidized, _____ bonds are made which are ___
If a compound has Cysteine residues (-SH groups) and is oxidized, disulphide bonds are made which are covalent bonds
Describe a hydrogen bond donor
The formation of a hydrogen bond requires both a hydrogen bond donor: a molecule with a hydrogen bonded to a highly electronegative atom such as oxygen or nitrogen
If Na2CO3 = 2 mol how many moles Na?
2x2=4
Why does nickel ion have green olor
The color arises because nickel(II) ion has partially filled d orbitals and the electrons in the lower energy d orbitals absorb visible light to move to the higher energy d orbitals.
in q=mcat , unit of temp and mass
Celsius and grams
two samples of same mass, one has more MW, which has more moles?
one with smaller MW
“X is titrated with Y” means that X is the ___ and Y is the___
“X is titrated with Y” means that X is the unknown concentration and Y is the titrant.
kcat is used to describe the rate-limiting step of catalysis under what conditions
kcat is used to describe the rate-limiting step of catalysis under saturating conditions of substrate.
product of aldol addition (aka condensation hasnt happened
B-hydroxy ketone
on the beta carbon there is a hydroxyl group
acceleration is decreasing uniformly, how does the velocity change with time?
non uniformly/linearly i.e. graph would be curved as slope would decrease
Why would someone use heat of combustion instead of boiling point to measure thermodynamic stability of isomers?
boiling point deals with INTERmolecular foces and bonds NOT INTRA
two mixtures are combusted, one released more heat than the other, what can be inferred?
more heat released -> less stable
Chelation
Ligand binding to a central atom with more than one covalent bond
Why does adding distilled water to a buffer not affect pH?
water will dilute concentrations of both acid and base in buffer so their ratio in the Henderson hasselbach will be the same
For a phosphate buffer solution, which species is the acidic vs basic one –> monosodium or disodium phosphate?
Monosodium is acidic bc imagine the formula NaH2PO4 vs Na2HPO4, the amount of Na attached will correspond to how many H+ have been lost and the species will lost protons will be considered the conjugate base
Initial velocity in michaelis menten needs to occur under what conditions
steady state
acetyl structure
carbonyl with a methyl group
Nitrogen charge in peptide backbone
positive
Porphyrin structure and found where
composed of four modified pyrrole subunits
found in heme
Pyrrole structure
5 membered heterocyclic ring with N
Hydroxylation needs what enzyme?
Oxidoreductase
pH goes down pKa and Ka go where?
pKa goes down
Ka goes up
if something is hydroxymethylated, it will more easily be deprotonated rather than protonated because
now it has a highly acidic hydorgen (H-O) on it
sound goes into two diff materials, does f change?
nah bc f depends on source
In Ksp expression, what is not included?
solids and pure liquids
carbon in its standard state is
solid - graphite
Electron affinity definition
the amount of energy that is liberated whenever a molecule or a neutral atom tends to acquire an electron from the other elements
____ is a special type of dipole-dipole attraction between molecules, not a covalent bond to a hydrogen atom.
H bonding
Convection occurs inside
fluid
Arrhenius eqn represents what theory
collision theory
critical point
density of gas = density of liquid
hard to distinguish between states
ammonium, acetate, alkali metal cations, nitrate are alll
soluble
4 colligative properties
vapor pressure depression, BP elevation, FP depression, Osmotic pressure
ideal solution?
strength of bonds broken = strength of bonds made
enthalpy of dissolution = 0
dismutation or disproportionation rxn
redox where one thing is both oxidized and reduced
titrant vs analyte
titrant is known
analyte is unknown
Acid base questions to find conc of weak acid bases, two eqns can be used depending on what info is given, which 2 eqn>
Henderson Hassel Balch and/or Kb/Ka equilibrium
If a drug and an inducing or enhancing agent have similar uptake rates, the agent should be administered where compared to drug and why
prior
prevent some cells randomly interacting with drug before agent reaches it
Excess base added to an organic compound, what might it do
hydrolyze any carbonyl groups
not all excess might be used so be careful
Why is Na2CO3 a bronsted base.. how made?
accepts protons
Made from a strong base and weak acid to become a basic salt
NaOH + H2CO3 –> Na2CO3 + H2O
Small insects walk on the free surface of water because?
surface tension
at the air–water interface, all hydrogen bonds in water face downward, causing the molecules of the water surface to bond together. Due to cohesion, the polar water molecules do not cling to nonpolar molecules (such as oils) like those found in the insect feet.
The insects do not sink through the free surface of water provided their weight is smaller than the surface tension!!!
Electric field inside conductor is 0 because
Conductors contain both atom-bound electrons and free electrons.
Free electrons arrange themselves on the surface of conductors, and their collective electric field produced inside the conductor cancels any external electric field.
The resulting electric field inside the conductor is zero.
Huckle’s rule?
Compound should have 4n + 2 pi electrons
n can be any integer
Color change in a titration depends on what property of indicator?
indicators pKa,
because color change will occur once it turns from HIn to In-
If 1 faraday = charge in 1 mol e-, what is 0.1 F equal to
Charge wise it would be 10^4 (since 1 F=10^5)
otherwise, 0.1 F = charge in 0.1 mol electrons
Pressure goes from 1 to 500 atm, what happens to volume of individual gas molecules and why
goes from ideal to non ideal behavior
goes from occupying no space to having volume of its own
characteristic of material that is good insulator but poor conductor
electrons in material cannot move to other atoms very easily
bc valence electrons tightly bound to atoms
sp3 geometry
tetrahedral
The solubility of any ionic basic anion will be increased in solution of __ pH
low
