gen chem Flashcards
1
Q
emission does what to the bands and energy
A
has bright bands and goes to a higher frequency
2
Q
PH can once or decr by what number
A
Ten fold
3
Q
when acids dissociate in soon what happens to ions
A
Stable
4
Q
what type of acids and bases will dissociate 100% in soln?
A
strong
5
Q
formula for acetic acid and what type of acid?
formula for acetate
A
weak
C2H4O2
C2H3O2
6
Q
when doing math problems with log and neg log, what is the ans to 1 x 10 ^-1 concentration?
A
- log [] will be 1
log of [] will be negative 1
7
Q
What is the relationship between the mass of an atom and the sum of the masses of its constituent particles?
A
sum of masses mass is greater
8
Q
A radioactive nucleus decays by emitting a positron particle. What is true about the resulting daughter nucleus?
A
Its atomic number decreases.
positive beta particles (positrons) essentially convert one of the protons into a neutron, thus decreasing the atomic number during the process
9
Q
Thallium-201 decays by electron capture. What are the atomic and mass numbers of the daughter nucleus, respectively?
A
Electron capture involves the addition of an electron to the nucleus with the conversion of a proton to a neutron. This results in mercury-201 as the product, making choice A correct.
Superscript: 201: subscript: 81: element symbol Tl: plus: superscript: 0: subscript: negative 1: electron or e ? Superscript: 201: subscript: 80: element symbol Hg
10
Q
to help remember anode and cathode charges
A
DONT PANIC
POSITIVE IS ANODE
NEGATIVE IS CATHODE
11
Q
when dealing with unknown concentrations for titrations, use
A
mv acid = mv base BUT BALANCE EQUATION FIRST to see if the ratio is equal
12
Q
H NMR spectroscopy can provide all of the following information EXCEPT:
A
A. the connectivity of atoms in a molecule.
like how many hydrogens are involved…
B. the number of nonequivalent hydrogens in a molecule.
C. the chemical environment of the hydrogen atoms in a molecule…… like if its near an acid
D. the splitting patterns of equivalent hydrogen atoms. Correct Answer
13
Q
why is the third ionization energy much higher than the first and second ionization energies?
A
the third is not at a higher energy level but the third electron is being removed from a completely full subshell
14
Q
beta + decay vs beta (-) decay
A
beta pos means that a protron goes to a neutron
beta minus means that you gain electrons
15
Q
opaque
A
not allow light to pass through
neg term
16
Q
why is phenothalien useful for titrations?
A
colorless for acid but if detects a base, will turn colors
17
Q
titrations are useful for?
A
finding an unknown concentration
18
Q
end point
A
titration changes color
19
Q
equivalence point
A
it is when the moles of H+ in solution equals the moles of OH- in solution, and all the acid (or base) in the original solution is neutralized.
20
Q
why do air bubbles occur in distillation methods?
A
similar to a boiling chip
The air bubbles break the surface tension of the liquid being heated and prevent superheating and bumping
21
Q
what are 4 things that makes a gas an ideal gas
A
no intermolecular forces (so no attraction to each other)
no volume (so don’t take space)
perfectly elastic
hard/round spheres
22
Q
what is the R constant for pv=nrt?
A
.0821 [ atm x L / mol x K ]
8.314 Pa . m^3 / mol x K
23
Q
Charles law formula
A
v1 /T1 = V2 / T2
always use kelvins and keep in mind that volume is on top because vol should be on y axis like rise over run
24
Q
3 avogrado law formula
A
1 mol = 6.022 x 10^23
v2-v1 / v1 = n2-n1 / n1
v1 / v2 = n1 / n2
25
ideal pressure vs real pressure
ideal pressure is bigger than the real pressure and because it is bigger, then that means that means that the ideal volume will have to be smaller than the real one bc (inversely prop to the ideal pressure)
26
define boltzman constant and what is the formula
as the temp incr, the Ke incr as well and are very correlated to each other
boltzman helps to connect molecules (instead of moles) to R gas constant
Kb = R for pascals / avogrado # = 1.38 x 10^ -23 J/K
27
moles formula
1 / 6.022 x 10^23
28
internal energy formula
U = Q - (W)
W is positive if work is done by the system, so U decreases. W is negative if work is done on the system, so U increases.
29
heat capacity vs molar heat capacity formulas
C = Q/ T is heat capacity and the molar is Q / nT
monoatomic, constant volume: 3/2R
monoatomic, constant pressure: 5/2R
diatomic, constant volume: 5/2R
diatomic, constant pressure: 7/2R
30
heat formula
Q=mcΔt: Q= the heat energy (Joules), ... water, at about 4.186 Joules/gram × °C), and t= the change in temperature in °C
31
why is helium the most ideal gas ?
it is the smallest of the noble gases so less mass and no intermolec force
32
standard state is aka
standard conditions
33
If a canister, with a moveable piston on top, had an increase in temperature applied to it, but the piston is prevented from moving, how does the pressure increase?
The work is only zero because there's no change in volume (W=PdeltaV, and delta V=0 in this case), but pressure still increases because the average kinetic energy of the particles in a gas is proportional to the temperature. So yes, the faster these particles are moving when they hit the wall (as a result of increased temp), the greater the force they exert on the wall, and since P=F/A, pressure increases.
34
what is NAG SAG
whenever u sag your pants, somone will nag you
always soluble elements
Nitrates
Acetate
Group 1 metals
Sulfates
Ammonium
Group 17 nonmetals
35
what are the exceptions for solubility
P pb2+ (LEAD)
M ercury
S ilver
PMS is never soluble with sulfate or group 17
CaSTRoBear
Calcium
strontium
barium
never soluble with sulfates
36
dissolution vs precipitate
dissol will turn into ions and are SPECTATOR IONS NOT INVOLVED IN THE NET IONIC EQTN
precip is ionic crystal formed from strong electrostatic attraction that is stronger than hydration force of solvent like h2o from breaking the precipitate
ONLY PRECIPITATE IS IN NET IONIC EQUATION
37
what happens when u add acid to a thing that is slightly soluble?
if a strong enough base like HF (NOT HCL) it will cause even more of a solubility....
base has to react with H3O+, if another acid like hcl, the solubility will stay the same.
38
salt bridge
as one part becomes pos charged the neg anions will go in that directi0on to neutralize to keep from becoming to pos or neg so that current of electrons can continue to flow
ex like sodium sulfate bc it has both cations and anions to keep the balance
39
anode in electrophoresis, galvanic cell, and electrolysis cell
anode is pos in electrophoresis
Anode is where oxidation occurs. For a galvanic cell, it is negative and for an electrolytic cell it is the positive terminal.
In a galvanic cell, the negative electrode is considered as the anode while a positive electrode is considered as the cathode. This maybe astonishing at first, but one way to justify it is if you consider the salt bridge(here, Na2SO4), you may notice that the anions tend to move towards the oxidation half-cell and we know that it is the anode towards which anions move.
Similarly, the cations tend to move towards the reduction half-cell, hence, cathode.
But, we also know that it is from the negatively charged terminal of a battery that electrons move out from towards the positively charged terminal. Here, the electrons flow from the oxidation half-cell (anode) towards the reduction half-cell(cathode).
40
formula for electrochemistry and how do u know half rxns should be pos or neg value ?
E°cell= E°cathode - (E°anode)
if metal is losing electrons it is + value
if gaining the new electrons, it will have neg value
usually anode is the one that is being oxidized
41
another word for galvanic cell is
voltaic (spontaneous cell)
delta G = neg value
electrocell = pos value
the pos/ neg values are opp for electrolytic cell
42
symbols for electrochemistry ..
what does single vertical line mean
what does double vertical line mean
single separates the anode from the cathode
anode will be on left of salt bridge (II) and cathod will be on right of (II )
double vertical line II means that saltbridge is present
43
gibbs energy for electrochem
delta G = (-) n F E
delta G will be neg if galvanic bc galvanic is always spontaneous.... can manipulate by multiplying if trying to correct number of moles u need
E is the cell voltage/ potential and will be value of 1.10 if pure solid form? cant manipulate the e by multiplying bc intensive so voltage is always same unless changing +/- sign
F is magnitude of charge carried by 1 mol of electrons
= 96, 500 Columb/mol
n is the number of moles usually but really the number of electrons being transferred
44
when given a electrical potential value of certain metal (topic has to do with electrochemistry) what does it tell u about other metals that are higher or lower in e potential?
if above intended value, the intended metal will not be able to oxidize but if there is a metal with a lower e potential value, the intended metal will be able to oxidize
45
formula for calculating equilibrium constant from the standard cell potential
set the two gibbs energy formula equal to each other and when u see circle in right top corner, it is under standard conditions
-nFE = RTlnkeq
R is 8.3 and T is 298 K
E = (0.0592 V / n) log K
46
how to solve this/ get rid of log
223 = log k
take 10 to the power (e) to both sides
10^ 223 = 10^ log
k= 10^233
big value causes it to go in fwd rxn
47
thermodynamics delta G formulas
delta G = G + RTlnkeq
delta G = H - TS
48
nerst equtn formula
allows u to calculate cell potential under non standard conditions
E potential = standard E potential - (RT/ nF ) (lnkeq)
u get this by combining the gibbs energy RTlnKeq formula with the nEF formula and solve for E
bc conditions and working with faraday (which has joules in it), use R = 8.314 and T = 298 K
or can use E = E standard E - (0.0592 / n ) (log Q)
49
log of 100 =
2
50
What if we are dealing with an equation like 3 moles of Solid Iodine reacting with 2 moles of Aluminum(3+) giving 6 moles of Iodine(-) and 2 moles of Solid Aluminum
Would the Reaction Quotient be?
[Iodine(-)]^6/[Aluminum(3+)^2
51
The voltage of a galvanic cell, E, depends on the concentration of reactants and products. The Nernst equation,
E = Eo – (0.0592/n)log(Q)
can be used to calculate the cell potential. Eo is the standard cell potential, n is the number of moles of electrons exchanged in the reaction, and Q is the reaction quotient. Which of the following is true regarding the value of E?
A. E is always less than Eo
B. E is always greater than Eo
C. E is always equal to Eo
D. E can be less than, greater than, or equal to Eo
According to the Nernst equation, the cell potential E will vary based on the logarithm of the reactant quotient Q. The reactant quotient follows the same equation as the equilibrium constant K, but measures the ratio of the actual concentration of products to concentration of reactants at any time during the reaction. Therefore, when Q > 1, log(Q) is positive and E < Eo. If Q < 1, log(Q) is negative, then E > Eo. Lastly, E is equal to Eo when Q = 1 because the log of one is equal to zero. Thus, E can be less than, greater than, or equal to Eo making D the correct answer.
52
The Nernst equation states:
E=E°−0.06 log([X]anode/ [Y]cathode)
For a concentration cell that has a potential of 0.089 V and utilizes Ni2+ solutions at the anode and the cathode, which of the following statements correctly describes the molar cell concentrations [Ni2+]anode and [Ni2+]cathode and the direction of electron flow within the cell?
A.[Ni2+] is greater at the anode; electrons flow from cathode to anode
B.[Ni2+] is greater at the cathode; electrons flow from anode to cathode
C.[Ni2+] is greater at the anode; electrons flow from anode to cathode
D.[Ni2+] is greater at the cathode; electrons flow from cathode to anode
The potential (E) is a positive value, thus the expression [x]/[y] must be less than 1 for the log of that to be negative so the resulting potential (0.089= E) is positive. Therefore, the concentration at the cathode is greater than that at the anode
If our anode>cathode we would get a negative number. If E is negative the reaction is not spontaneous so In order to have a positive, spontaneous E we would have to have a larger concentration at the cathode...
53
high ksp vs low ksp
When the theoretical concentration of ions in solution exceeds Ksp, precipitation of the solid can be expected. When the product of the concentrations of the two ions is less than the Ksp, the solution is not yet saturated
54
oxyacid
is an acid that contains an oxygen atom bonded to a hydrogen atom and at least one other element. An oxyacid dissociates in water to form the H+ cation and the anion of the acid. An oxyacid has the general structure X-O-H. Also Known As: oxoacid.
55
how does a weak acid act with electricity
weakly conducts electricity
56
(triacyl glycerols have what main functional groups
cooh
57
Prostaglandins appearance
tend to be polyhydroxylated meaning many hydroxyl groups, and tend not to have as many fused rings like maybe 1-3
58
ionization formula is when
An ionization reaction generally describes the dissociation of a neutral compound into its constitutive ions (e.g., HCl → H+ + Cl–), but the oxidation states of the atoms in the compounds remain unchanged before and after the reaction
59
the azimuthal quantum number (l)
determines the shape of the orbital
60
catalytic efficiency formula
Vmax = kcat * [E]
Just replace the Vmax in the M-M equation
V = ( {kcat * [E]} + [S])/( Km + [S])
61
kd relationship with km
Kd, however, is the dissociation constant, and measures the dissociation of the substrate from the ES complex. Therefore, the larger Kd is, the less affinity the enzyme has for the substrate.
low Km means high affinity
low Kd means high affinity, which means S has high affinity to bind to E so it doesn't dissociate from E
62
what would this ratio mean:
Ka/K0
it has to have a 1: 1 rqatio so just think of 100%
so more of ka would bring u less of ko so therefore they are inversely proportional
63
when looking at graphs, how do u tell if it is just straight diagonal line or exponential
straight diagonal line is proportional and shows going up little by little so its constant but changes for x and y value at fixed ratio.
but exponential shoots up a lot at the end but soooo fast for the y value while x value stays constant
64
14C labeling pattern are what type of carbons in an organic structure
the ones that are only bound to hydrogen and nothing else
65
when it comes to thermodynamic conditions, which organization of structures are favored?
rings but usually five or better (espec 6 membered rings) but never 4 or 3 bc of ring strain
better to be in 5 or 6 membered ring than a regular line alkane/ene/yne
66
C=C double bond, which would give a stretch
1580–1610 cm^–1
67
What factor explains how a single stereoisomer is formed in Reactions?
Neither reactant is chiral, but a chiral product forms because the catalyst (the enzyme) is chiral.
68
Myopia is a condition of the eye where the crystalline lens focuses the light rays to a position between the lens and the retina. To correct for this condition, a thin lens is placed in front of the eye that will help to focus light on the retina. The type of lens required is:
diverging
Myopia is treated with diverging lenses, because the power of the eye’s cornea and lens system is too high, so a negative power lens is required to lower it appropriately. Put another way, the myopic eye focuses light from distant objects prior to its reaching the retina, and the addition of a diverging lens moves the focal point further back to reach the retina
69
The goal of most polypeptide and protein extraction methods
Sublimation, the phase change of water from solid to gaseous state, eliminates the water from the sample without raising the temperature and possibly denaturing the protein
70
Which two amino acids contribute to the stabilization of ADP binding described in the passage?
both His and Arg side chains can carry a positive charge. They would have favorable ionic interactions with the negatively charged phosphates of ADP.
71
rna vs dna structure
It contains a nucleotide with a hydroxyl group on the 2’ carbon, so it is not a deoxynucleotide
72
What is the frequency of the emitted gamma photons? (Note: Use Planck’s constant h = 6.6 x 10–34 Js and the elementary charge e = 1.6 x 10–19 C.)
note that gamma requires very high freq bc takes very high energy
E is equal to 140 keV which is 1.4 x 105 eV and 1 eV=1.6 x 10-19 J
f= (1.4 x 105)*(1.6 x 10-19)/ (6.6 x 10-34) which if you estimate your numbers and round, it comes out to around 4 x 1019 Hz
73
how many eV is equal to joules
1 eV=1.6 x 10-19 J
74
are noble gases electron acceptors or donators
neither because they are already stable
75
why do transition metals generate a color change in a soln?
Transition metals generate colors in solutions because of partially filled D orbitals. Fully filled or completely empty d orbitals will not produce color. However -- partially filled/unfilled d-orbitals can produce color because it is the only orbital that can split into two different energy levels, allowing some of its electrons to jump up to the higher energy level and transmit visible light (HOMO/LUMO)
76
how can u tell which has a configuration that is identical to that of a Compound
do the config (R or S) of the config.. so if R look for the ans choice with R
77
capacitors
two separate metals store charge but same charge in magnitude
= q/V
78
Ingested acetic acid is a common source of biochemical acetyl groups, including those that form acetyl-CoA. Acetic acid dissociates in solution according to the following equation:
C2H4O2 <=> C2H3OO- + H+
```
If sodium acetate is added to a solution of acetic acid in excess water, which of the following effects would be observed in the solution?
Decreased pH
Increased pH
Decreased pKeq (pKa)
Increased pKeq (pKa)
```
B is the correct answer.
Adding sodium acetate increases the number of acetate ions present. According to Le Châtelier’s principle, this change will push this reaction to the left, resulting in a decrease in the number of free H+ ions. Because pH is determined by the hydrogen ion concentration, a decrease in the number of free protons will increase the pH. An acid’s Ka (which is simply the Keq for acid dissociation) will remain constant under a given temperature and pressure, eliminating choices (C) and (D).
79
grahams law of effusion
Graham found experimentally that the rate of effusion of a gas is inversely proportional to the square root of the mass of its particles.
rate A / Rate B = sqr root [molar mass B/ Molar mass A]
80
relationship of pressure vs volume vs temp
Both a change in temperature and a change in volume can affect a gas's pressure. So if one of those two variables is kept constant, as in choices (A) and (B), we'll definitely be able to predict which way the pressure will change. At a constant volume, heating the gas will increase its pressure, and cooling the gas will decrease it. What about when both temperature and volume are changing? If both changes have the same effect on pressure, then we can still predict which way it will change. This is the case in choice (D). Cooling the gas and increasing its volume both decrease pressure. Choice (C), on the other hand, presents too vague a scenario for us to predict definitively the change in pressure. Heating the gas would amplify the pressure, while increasing the volume would decrease it. Without knowing the magnitude of each influence, it's impossible to say whether the pressure would increase, decrease, or stay the same.
81
Experimenters notice that the molar concentration of dissolved oxygen in an enclosed water tank has decreased to one-half its original value. In an attempt to counter this decrease, they quadruple the partial pressure of oxygen in the container. What is the final concentration of the gas?
A. Half the original concentration
B. The same as the original concentration
C. Double the original concentration
D. Quadruple the original concentration
C
82
partial pressure formula
total pressure x % of particular gas in the total
83
```
A large cylinder is filled with equal volumes of two immiscible fluids. A balloon is submerged in the first fluid; the gauge pressure in the balloon at the deepest point in the first fluid is found to be 3 atm. Next, the balloon is lowered all the way to the bottom of the second fluid, where the hydrostatic pressure in the balloon reads 8 atm. What is the ratio of the gauge pressure accounted for by the first fluid to the gauge pressure accounted for by the second fluid?
A. 1:03
B. 3:04
C. 3:05
D. 3:08
```
The question isn’t worded the best, but the layout is as such: a cylinder is filled with two immiscible liquids (think water and oil). The first liquid is on the top (less dense) and the second liquid (more dense) will be at the bottom. You are looking for the gauge pressures of each liquid individually. Therefore, the second liquid’s hydrostatic pressure at the bottom includes both the liquid above (first liquid) as well as the atmospheric pressure. You must subtract 3atm (pressure of liquid above) and 1 atm (air pressure) in order to get the gauge pressure of only liquid two. Let me know if that makes sense, I’ll try and explain with pictures if that doesn’t work
So the gauge pressure in the first liquid is, as it states, 3atm. Now for the second liquid, the question provides the hydrostatic pressure. Phydrostatic= gauge pressure + atmospheric pressure. The pressure above the bottom liquid is equal to 3 atm, from the fluid above, plus 1atm which is the atmospheric pressure.
Therefore, the gauge pressure of the second liquid is equal to 8atm-3atm-1atm=4 atm
Ratio is 3:4
84
The gaseous state of matter is characterized by which of the following properties?
I. Gases are compressible.
II. Gases assume the volume of their containers.
III. Gas particles exist as diatomic molecules.
I and II
85
The ideal gas law can be modified to include density (ρ) by?
```
PV = nRT
PV= mass of particle RT / molecular mass of particle
```
P = density RT / Molar mass
86
The kinetic molecular theory states that:
A. the average kinetic energy of a molecule of gas is directly proportional to the temperature of the gas in kelvin.
B. collisions between gas molecules are inelastic.
C. gas particles occupy discrete areas of space.
D. all gas molecules have the same kinetic energy at the same temperature.
A
87
```
Ideal gases:
I. have no volume.
II. have particles with no attractive forces between them.
III. have no mass.
A. I only
B. II only
C. I and II only
D. I, II, and III
```
B
Ideal gases are said to have no attractive forces between molecules. While each particle within the gas is considered to have negligible volume, ideal gases as a whole certainly do have a measurable volume, thus option I is eliminated. Gases have molar masses, thus option III is eliminated.
88
rate of rxn for chem formula
change in concentration / change in time
| - should always be pos value
89
rate law formula
R = k [A]^1 [B]^2
R = rate of rxn (only R is effected with concentration change of reactants not k bc k is a constant
k= rate constant k changes depending on the order of rxn
A and B are reactants
90
rate determining step
slowest step of the rxn
91
molality
defined as moles of solute divided by kilograms of solvent. 5L of water is equivalent to 5kg of solvent.
92
electrolytic cells do what? spontan or nonspontan?
Electrolytic cells: convert electrical energy to chemical energy. Redox Reaction is non-spontaneous and electricity has to be supplied. Anode is positive, cathode is negative and the electrons from the battery enter through the cathode and come out from anode (Think flow of negativity).
93
coordinate covalent vs ionic bonding
Ionic bonding, as the name suggests, are formed between ions - ions which are oppositely charged. Positive ions, or cations take part in ionic bonding with negative ions, or anions. In ionic bonding, there is an electrostatic attraction between cations and anions.
Coordinate bonding is a form of covalent bonding but with a nonmetal without neg charge and transition model. NO SUCH THING AS COORDINATE IONIC. Covalent bonding is a bond formed when atoms of elements share electrons to form that bond. In coordinate bonding one atom donates it's electrons to form the covalent bond without the other atom contributing. In normal cases, in the usual covalent bond, a single bond is formed when both atoms contribute an electron each. However in a coordinate bond, one atom contributed both the electrons. For example, the lone pair of electrons on nitrogen in ammonia is used to form a coordinate bond with a proton (for simplicity I'll use proton instead of oxonium).
94
In [Cu(NH3)4]2+, the subscript 4 indicates which of the following
only coord # for Cu BUT NOT OXID #
95
coordination # def
Coordinate number is the # of bonds that the central ion makes with a neutral atom. (NH3 is neutral, Cu2+ is the central ion)
96
charge formula
The formula for charge is q = ne
q is the amount of charge (in Coulombs)
n is the number of electrons
e is the elementary charge (1.6 x 10-19 C)
you are looking for the total number of electrons that were ripped away from it (since you can't move protons).
97
potential energy for spring formula
1/2kx^2
