GENERAL CHEM Flashcards
1
Q
what is the mass and charge a proton?
A
mass - approximately 1 atomic mass unit (amu)
charge - +1 e (fundamental unit of charge)
2
Q
what does the atomic number (Z) of an element tell you?
A
the number of protons found in an atom of that element
3
Q
what does the mass number (A) of an atom tell you?
A
it is the sum of the protons and neutrons in the atom’s nucleus
4
Q
what are isotopes?
A
atoms that share an atomic number but have different mass numbers due to a different number of neutrons
5
Q
what convention is used to show both the atomic and mass number of an atom X?
A
A over Z next to X
6
Q
is the electrostatic or gravitational attractive force greater for subatomic particles and why?
A
electrostatic because the masses of subatomic particles are so small
7
Q
do electrons closer to or farther from the nucleus have higher energy?
A
farther
8
Q
what are valence electrons
A
electrons that are farthest from the nucleus
- have strongest interactions with the surrounding environment and weakest interactions with the nucleus
- involved in bonding
9
Q
atomic _____ is nearly synonymous with ______ number. atomic _______ is a _________ average of naturally occurring isotopes of that element
A
mass - mass
weight - weighted
10
Q
what are the units of molar mass
A
g/mol
11
Q
what is the equation for angular momentum
A
L = mvr
12
Q
what is the Planck relation
A
E = hf
12
Q
what is Bohr’s equation for possible values of angular momentum of an electron
A
L = (nh) / 2π
n = principle quantum number
13
Q
what is Bohr’s equation for the energy of an electron
A
E = - RH / n^2
RH = Rydberg unit of energy equal to 2.18 x 10^-18 J/electron
14
Q
when electrons go from a higher to a lower energy state, they _____ photons
A
emit
15
Q
when electrons go from a lower to a higher energy state, they _______ photons
A
absorb
16
Q
what is the equation for the electromagnetic energy of these photons
A
E = (hc) / λ
17
Q
as electrons go from a lower to a higher energy level, they get _______ (mnemonic)
A
AHED
Absorb light
Higher potential
Excited
Distant (from nucleus)
18
Q
what is an electron’s atomic emission spectrum
A
a spectrum of distinct energy levels unique to that element (based on the electrons it contains)
- when electrons drop from an excited state to ground state, they emit photons with wavelengths corresponding to that specific energy transition
19
Q
what is the Lyman series
A
group of hydrogen emission lines corresponding to transitions from energy levels n>/2 to n = 1
20
Q
what is the Balmer series
A
group of hydrogen emission lines corresponding to transitions from energy levels n>/3 to n=2
21
Q
what is the Paschen series
A
group of hydrogen emission lines corresponding to transitions from energy levels n>/4 to n=3
22
Q
the energy of the emitted photon corresponds to the ___________
A
difference in energy between the higher-energy initial state and lower-energy final state
E = (RH)[ 1/ni^2 - 1/nf^2 ]
23
Q
T or F: an electron’s change in energy is the same in between any two energy levels
A
T
- conservation of energy
- the amount of energy absorbed to go higher equals the amount of energy emitted to go lower
24
what is the Heisenberg uncertainty principle
it is impossible to simultaneously determine, with perfect accuracy, the momentum and position of an electron
- can't assess one while not affecting the other
25
what are the four quantum numbers
n, l, ml , and ms
26
what is Pauli's exclusion principle
no two electrons in a given atom can possess the same set of four quantum numbers
27
what is the maximum number of electrons within a shell
2n^2
28
the difference in energy between two electron shells decreases as the distance from the nucleus __________
increases
29
for any principal quantum number n, there will be n possible values for l, ranging from 0 to ______
n - 1
30
what is the azimuthal quantum number
l
- tells you the shape and number of subshells within a given shell
31
what is spectroscopic notation
shorthand representation of principal and azimuthal quantum numbers
- L = 0 --> s
- L = 1 --> p
- L = 2 --> d
- L = 3 --> f
32
what is the maximum number of electrons within a subshell
4l + 2
33
what is the magnetic quantum number
ml
- Specifies the particular orbital within a subshell where an electron is most likely to be found
34
the possible values of ml are the integers between ________
-l and +l , including 0
35
for any value of l, there will be __________ possible values of ml
for any n, this produces _______ orbitals
for any n, there will be a maximum of _______ electrons
2l + 1
n^2
2n^2 (two per orbital)
36
what is the spin quantum number
ms
- tells you the spin of the electron
- two possible values, +1/2 and -1/2
37
electrons with opposite spins are said to be _________ and must be in ________ orbitals
paired ; different
38
electrons with the same ms value are said to have _________
parallel spins
39
what is the aufbau principle
electrons fill from lower to higher energy subshells and each subshell will fill completely before electrons begin to enter the next one
40
what is the n + l rule
rule for ranking subshells by increasing energy
- the lower the sum of n + l, the lower the energy of the subshell
- if the sum for two shells is equal, the shell with the lower n value has a lower energy
41
what is Hund's rule
within a given subshell, orbitals are filled such that there are a maximum number of half-filled orbitals with parallel spins
42
what are paramagnetic materials
materials composed of atoms with unpaired electrons and will orient their spins in alignment with a magnetic field
43
what are diamagnetic materials
materials consisting of atoms that have only paired electrons and thus are slightly repelled by a magnetic field
44
which elements only have paired electrons
elements that come at the end of a block
45
which elements violate aufbau
chromium, copper, and silver
46
what is the periodic law
the chemical and physical properties of the elements are dependent, in a periodic way, upon their atomic numbers
47
periods are ______ and groups/families are ________
rows ; columns
48
periods graphically represent the ________ and groups help to determine the ________
principal quantum number ; valence electron configuration
49
what are the representative elements
elements that have their valence electrons in either s or p subshells
50
what are the nonrepresentative elements
the transition elements and the lanthanide and actinide series
51
where are metals found on the periodic table
left side and middle
- include the first two groups (except H), transition elements and the lanthanide and actinide series
52
what are the properties of metals
they are lustrous (shiny), malleable/ductile, have high melting points, and good conductors of electricity
53
T or F: metals easily give up electrons
T
54
what are the properties of nonmetals
dull, poor conductors of electricity, and brittle
55
where are nonmetals found in the periodic table
upper right side starting with carbon and then diagonal staircase down to Rn
56
where are metalloids found in the periodic table
diagonal staircase down from boron to Po and At
57
what are the periodic trends from left to right
atomic radius decreases, ionization energy increases, electron affinity increases, electronegativity increases
58
what is a zeroth-order reaction and what is its rate law
a reaction whose rate is independent of concentration
rate = k
59
what is a first-order reaction and what is its rate law
a reaction whose rate is directly proportional to the concentration of one of the reactants
rate = k[A]
60
what is a second-order reaction and what is its rate law
a reaction that either depends on the square of the concentration of one product or on concentrations of both products
- for square one - rate = k[A]^2
61
what does the Arrhenius equation show
the effect of temperature change on rate constant and thus rate of reeaction
62
what do you need in an amino acid side chain for a pi-stacking interaction
an aromatic ring
63
what do you need in an amino acid side chain for a salt bridge to form?
a charged side group that is the opposite charge of what it's forming the salt bridge with
64
what does the Hill coefficient tell you
cooperativity
- a Hill coefficient greater than 1 is positive cooperativity
- a fractional coefficient (less than 1) is negative cooperativity
- a coefficient equal to 1 is no cooperativity
65
what is Ki
inhibition constant
- concentration of the inhibitor at which the reaction rate is half of the maximum reaction rate
66
pyrrole is a _____
five-membered aromatic heterocycle containing 1 nitrogen atom
- C4H5N
67
what is Boyle's law
if temperature and amount of gas remain constant, the absolute pressure exerted by a gas is inversely proportional to its volume
P1V1 = P2V2
P = 1/V
68
what is Charles's law
when pressure is constant, the Kelvin temperature and volume are proportional to each other
V1/T1 = V2/T2
69
T or F: steroids are nonhydrolyzable lipids
T
70
how many isoprene units and fused rings do steroids have
6 ; 4
71
what is an esterase
enzyme that hydrolyzes particular esters into acids and alcohols or phenols
- RCOOH + R'OH
72
what is an amidase
enzyme that hydrolyzes acid amides usually with the liberation of ammonia
- RC(=O)NHR' --> RCOOH + R'NH2
73
what is a phosphatase
an enzyme that removes a phosphate group from a protein
74
what is Hess's Law
the heat of a reaction will sum and be the same no matter what
- even if you break it into tiny steps, it will release or absorb the same amount of heat by the end
75
what is the chemical formula of formate
conjugate base of formic acid (HCOOH)
- HCOO-
76
what is the chemical formula of carbonate
CO3 (2-)
77
what is the chemical formula of bicarbonate
HCO3-
78
what is the chemical formula of acetate
CH3CO2
C2H3O2
79
anion-exchange chromatography separates out proteins with ______ while cation-exchange chromatography separates out proteins with ______
negative charges (these are the ones that bind to the resin surface) ; positive charges
anion exchange has a positive resin that the negative molecules stick to ; cation exchange has a negative resin that the positive molecules stick to
80
what is the heat of fusion
the amount of energy required to convert a solid to a liquid (melting ice)
81
what is the function of a protein kinase
catalyzes the transfer of a phosphate (specifically y-phosphate from ATP) to other substrates
82
what are the three labels for the three phosphates in ATP
a, B, and gamma
83
what is the oxidation number of H
+1
- unless it's with something more electropositive (like in NaH it's -1)
84
what is the oxidation number of O
-2
- unless it's in a peroxide (H2O2, Na2O2) in which case it's -1
85
what are the oxidation numbers of diatomic species (H2, N2, etc)
always 0
86
T or F: ions always have the same oxidation numbers as their charges
T
oxidation number of Ca is 2 as it is 2+
87
what is the oxidation state of N in NH4+
-3
4H means + 4 ; + charge means there's a +1 left over
88
how many liters does 1 mol of gas occupy at STP?
22.4 L
89
standard conditions vs STP
standard conditions - 25˚C, 298.15 K, 24L of gas
STP - 0˚C, 273K, 22.4L of gas
90
Which of the following oxidative transformations is unlikely to occur?
A.A primary alcohol to an aldehyde
B.A tertiary alcohol to a ketone
C.An aldehyde to a carboxylic acid
D.A secondary alcohol to a ketone
B.A tertiary alcohol to a ketone
91
what's the difference between a primary and secondary alcohol
primary alcohol - hydroxyl group is connected to primary carbon (only connected to one other carbon)
secondary alcohol - hydroxyl group is connected to secondary carbon (connected to 2 carbons)
92
how to tell if something is Z or E configuration
Z - high priority groups are on the same side of the double bond
E - high priority groups are on the opposite side of the double bond
93
what's the IUPAC procedure for naming something?
By IUPAC rules, first identify the longest unbroken chain of carbon atoms. Next, number the carbon atoms in this chain starting from the end that gives C=C the lowest numbers. The double bond is identified by the position of the carbon atom from the lowest numbered end (2), and then the methyl group is assigned at the 3-position. The stereochemical designator for the double bond is Z because the highest priority groups (methyl at C2 and ethyl at C3) occur on the same side of the double bond. The name is therefore Z-3-methylpent-2-ene. (specific example)
94
Two vectors of magnitudes |A| = 8 units and |B| = 5 units make an angle that can vary from 0° to 180°. The magnitude of the resultant vector A + B CANNOT have the value of:
A.2 units.
B.5 units.
C.8 units.
D.12 units.
A. 2 units
smallest value is 3 units when they have an angle of 180˚ between them and largest value is 13 units when they have 0˚ between them
95
what are the equations for electric field
E = V/d
F = qE
E = kq/r^2
96
1 Hz is also equal to _____
cycles per second
97
Group 1 elements are called _____ and Group 2 elements are called ______
alkali metals ; alkaline earth metals
98
a double bond contains what kind of bonding interactions
one sigma, one pi
99
what is sublimation
phase change from solid to gas
100
what is the critical point on a pressure-temperature graph
the point where the liquid and gaseous phase merge together as a single phase
101
what is an imine
functional group containing a carbon-nitrogen double bond
102
what is a carbamate
both an amide and ester; a nitrogen atom of the amide and oxygen atom of the ester share a carbonyl group
103
what is an imidazole
five-membered heterocyclic system that has both an -NH- and -N=
104
what are lactones
cyclic carboxylic esters
105
which reducing agent is stronger: LiAlH4 or NaBH4
LiAlH4 - can be used on esters, carboxylic acids, and acid amides
NaBH4 (weaker) - only aldehydes and ketones
106
what is an acetal
has structure R1O–CR2R3–OR4 where R1 and R4 are carbon groups and R3 and R2 are a carbon and a H
107
T or F: hydroxide can hydrolyze esters (and open up lactone rings)
T ; adds an H to the ester
108
hydrolysis vs condensation reactions
hydrolysis - use water to break molecule into smaller molecules ; break bonds and water is added to remaining fragments
condensation - smaller molecules combine to form larger molecules with the loss of a water
109
what is characteristic of ping-pong substrate binding mechanism
no ternary complex is formed
- also called double-displacement
110
what is ordered vs random-order substrate binding mechanism
ordered - TP substrate binds first without any catalysis occurring and then dNTP
random order - either substrate could bind first
111
what is the buffering capacity of a buffer
+/- 1 pH unit away from the pKa
112
The electric field inside each of the conductors that forms the capacitor in the defibrillator is zero. Which of the following reasons best explains why this is true?
A.All of the electrons in the conductor are bound to atoms, and thus there is no way for an external electric field to penetrate atoms with no net charge.
B.Free electrons in the conductor arrange themselves on the surface so that the electric field they produce inside the conductor exactly cancels any external electric field.
C.Free electrons in the conductor arrange themselves on the surface and throughout the interior so that the electric field they produce inside the conductor exactly cancels any external electric field.
D.All electrons in the conductor, both free and bound, arrange themselves on the surface so that the electric field they produce inside the conductor exactly cancels any external electric field.
B.Free electrons in the conductor arrange themselves on the surface so that the electric field they produce inside the conductor exactly cancels any external electric field.
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.
113
what is osmotic pressure
the diffusion of solvent across a semipermeable membrane from a solution of lower concentration to one of higher concentration during osmosis creates osmotic pressure
P = iMRT
i = van't Hoff index ; M = concentration ; R = gas constant ; T=temperature
114
what is the electron configuration for Fe2+?
the configuration for neutral Fe is 1s2 2s2 2p6 3s2 3p6 4s2 3d6
1s2 2s2 2p6 3s2 3p6 3d6
- the two electrons were taken from the 4s subshell bc it is the highest shell
115
what does it mean when orbitals are degenerate
they have the same energy
116
when ligands cause a difference in energy of orbitals, this can result in _______
the absorption of different wavelengths of light
- example: hemoglobin is red when bound to O2 bc it interacts with heme's d orbitals
117
what is a coordinate covalent bond
bond between a central atom and a ligand where the ligand donates both of the electrons involved
118
what is the coordination number
the number of coordinate bonds to the central atom
119
anode is the site of _________ and cathode is the site of __________
oxidation ; reduction
120
what is the definition of an intermediate
a transient chemical species that is produced in one elementary step and consumed in a subsequent step
121
what are the changes associated with gamma decay
mass number: +0
atomic number: +0
elemental identity is unchanged
a gamma ray (high-energy photon) is released
122
what are the changes associated with B- decay
mass number: +0
atomic number: +1
a neutron converts to a nuclear proton and emits an electron and an antineutrino
123
what are the changes associated with B+ decay
mass number: +0
atomic number: -1
a nuclear proton converts to a neutron and ejects a positron and a neutrino
124
what are the changes associated with electron capture E (a form of B decay)
mass number: +0
atomic number: -1
a proton captures an electron near the nucleus and converts a neutron without any emission
