chem final Flashcards
What is meant by the term oxidation?
The loss of electrons by the compounds in chemical reactions.
On which side of an oxidation half-reaction do the electrons appear?
On the right side (products).
What is meant by the term oxidant?
It is the species that’s being reduced.
What is meant by the term oxidizing agent?
The compound which gains electrons in the redox reaction.
What is meant by the term reduction?
The gain of electrons by the compounds in chemical reactions
On which side of a reduction half-reaction do the electrons appear?
On the left side (reactants)
What is meant by the term reductant?
It is the species that’s being oxidized.
What is meant by the term reducing agent?
The compound that loses electrons in the redox reaction.
For a reduction potential to be a standard reduction potential, the substances in the reaction or half-reaction must be at _________, _______M aqueous solutions and ____ atm
gas pressures.
standard conditions
1
1
What is the standard reduction potential of a standard hydrogen electrode?
0 V
It is not possible to measure the standard reduction potential of a single half-reaction because each voltaic ____ consists of _____, half-reaction(s) and only the potential of a ____________ can be measured.
cell
2
complete cell
What is electrolysis?
The process of using an electric current to break up an ionic compound and form elements.
Are electrolysis reactions thermodynamically spontaneous?
no
Spontaneous reactions don’t include an external source or agent, and the electrolysis reactions involve electricity. So, they are not spontaneous.
What is an electrolytic cell?
An electrolytic cell is an electrochemical cell that uses electricity to make a non spontaneous redox reaction.
The negative terminal of a voltage source is connected to an electrode of an electrolytic cell. Is the electrode the anode or the cathode of the cell?
The electrode is the cathode.
The electrode connected with the negative terminal of a battery is defined as a cathode.
The electrolysis of water is often done with a small amount of sulfuric acid added to the water. What is the role of the sulfuric acid?
The ions in sulfuric acid will increase the conductivity of water, and help the electrolysis of water to happen more quickly.
Is lightening spontaneous or non-spontaneous?
spontaneous
Is ripe banana spontaneous or non-spontaneous?
spontaneous
Is sugar dissolving in hot coffee spontaneous or non-spontaneous?
spontaneous
Is Nitrogen forming N2 spontaneous or non-spontaneous?
spontaneous
Is the formation of CH4 and O2 molecules from CO2 and H2O at room temp, spontaneous or non-spontaneous?
non-spontaneous
Is the vaporization of liquid water to steam at a pressure of 1 atm endothermic or exothermic>
endothermic
At what temp is the vaporization of liquid water to steam at a pressure of 1 atm a spontaneous process>
above 100 deg C
At what temp is the vaporization of liquid water to steam at a pressure of 1 atm a non-spontaneous process>
below 100 deg C
At what temp is the vaporization of liquid water to steam at a pressure of 1 atm, at what temp are the stages in equilibrium
at 100 deg C
A system goes from state 1
to state 2
and back to state 1.
Is ΔE the same in magnitude for both the forward and reverse processes?
yes
A system goes from state 1 to state 2 and back to state 1.
Without further information, can you conclude that the amount of heat transferred to the system as it goes from state 1 to state 2 is the same or different as compared to that upon going from state 2 back to state 1 ?
no
A system goes from state 1
to state 2 and back to state 1
Suppose the changes in state are reversible processes. Can you conclude anything about the work done by the system upon going from state 1
to state 2
as compared to that upon going from state 2
back to state 1
?
The magnitudes of the work are equal, but the signs are opposite.
If the changes of state are reversible, the two paths are different, w(1→2)=−w(2→1).
Is this process spontaneous or non spontaneous?
alignment of iron fillings in a magnetic field
spontaneous
Is this process spontaneous or non spontaneous?
the dissolving of HCl in water to form hydorchloric acid.
spontaneous
Is this process spontaneous or non spontaneous?
rxn of H gas w O2 gas to form water vapor at room temp
spontaneous
Is this process spontaneous or non spontaneous?
melting of ice cubes at -10 deg C and 1 atm
non spontaneous
Is this process spontaneous or non spontaneous?
seperating a mixture of N2 and O2 into 2 seperate samples, one with pure N2 and one with pure O2.
non spontaneous
Do you need to specify the temperature to calculate the entropy change?
Yes, because entropy is thermodynamic. Since entropy is a thermodynamic property, its value is related to the temperature of the system.
Label CH3COO−
as being a strong base, a weak base, or a species with negligible basicity.
weak base
Write the formula of CH3COO−
conjugate acid
CH3COOH
Indicate whether the conjugate acid of CH3COO−
is a strong acid, a weak acid, or a species with negligible acidity.
weak acid
Label HCO3−
as being a strong base, a weak base, or a species with negligible basicity.
weak base
Write the formula of HCO3−
conjugate acid
H2CO3
Indicate whether the conjugate acid of HCO3−
is a strong acid, a weak acid, or a species with negligible acidity.
weak acid
Label O2−
as being a strong base, a weak base, or a species with negligible basicity.
strong base
Write the formula of O2−
conjugate acid
OH−
Indicate whether the conjugate acid of O2−
is a strong acid, a weak acid, or a species with negligible acidity.
species with negligible acidity
Label Cl−
as being a strong base, a weak base, or a species with negligible basicity.
species with negligible basicity
Write the formula of Cl−
conjugate acid
HCl
Indicate whether the conjugate acid of Cl−
is a strong acid, a weak acid, or a species with negligible acidity.
strong acid
Label NH3
as being a strong base, a weak base, or a species with negligible basicity.
weak base
Write the formula of NH3
conjugate acid
NH4+
Indicate whether the conjugate acid of NH3
is a strong acid, a weak acid, or a species with negligible acidity.
weak acid
Based on the ion-product constant for water, Kw
, the product of the [H+]
and [OH−]
concentrations is
10 ^ -14
In a neutral water solution, the concentration of H+ and OH- would both be….
10 ^ −7
if a water solution has an OH- value less than _____ than the solution is … if the OH value is more… than it is
10 ^ −7
acidic
basic
If a neutral solution of water, with pH=7.00
, is cooled to 10 ∘C, the pH rises to 7.27.
H = ……
H+ = OH-
Ammonia, NH3, acts as an Arrhenius base because it _____
the concentration of hydroxide ion, OH−
in aqueous solution.
increases
It acts like a Br ø
nsted-Lowry base because it is a proton, H+…
acceptor
It acts like a Lewis base because it is an electron pair…
donator
If a substance is an Arrhenius base, it _____ be a Brønsted-Lowry base _____ a Lewis base.
MUST
AND
Predict whether the equivalence point of each of the following titrations is below, above, or at pH=7
NaHCO3 titrated with NaOH
above PH 7
Predict whether the equivalence point of each of the following titrations is below, above, or at pH=7
NH3 titrated with HCl
below pH=7
Predict whether the equivalence point of each of the following titrations is below, above, or at pH=7
KOH titrated with HBr
at pH=7
what are the strong acids (7)
HCl
HNO3
H2SO4
HBr
HI
HClO4
HClO3
what are the strong bases (6)
LiOH
NaOH
KOH
Ca(OH)2
Sr(OH)2
Ba(OH)2
sucrose is made of…
glucose and fructose
in addition to alcohols, a molecule of glucose contains which functional group?
aldehyde.
Which are the groups NOT functional in 2-propanol?
hydroxyl
alcohol
which functional groups always contain Nitrogen?
amines and amides.
amines are…
a derivative of ammonia NH3
aldehydes have…
carbonyl group at the end of their chain.
carbonyl group
a double bond between C and O … C=O
which group has a CARBONYL?
alcohol
ether
carboxylic acid
amine
carboxylic acid
which functional group does NOT contain oxygen?
amine
amide
ester
ether
Amine
the major organic product formed when 2-butene reacts with excess Br2 is….
2, 2, 3, 3 - tetrabromobutane
the major organic product formed when HBr reacts with 2-Butane is….
2-Bromobutane
the correct IUPAC name for CH3-CH2-CH2-CH=CH2 is…
1-Pentene
which term describes at least one carbon-carbon bond in 2,4-dimethyl-1-hexene?
double. (ends in ‘ene’, alkene)
which term describes the carbon-carbon bonds in Benzene?
delocalized pi bonds
C10H22 is the molecular formula of…
alkane
C3H6 is the molecular formula of…
alkene (double bonds on either ends)
Aromatics have _______ because theyre more stable
substitution
molecule names containing ‘ol’ have…
OH groups wherever the ‘ol’ is
ethers have…
oxygen in the middle of the chain
most common substance in vinegar?
acetic acid
why cant spontaneous radioactive decay be a zero-order or second-order kinetic process?
spontaneous radioactive processes are unimolecular processes leading only to a first order kinetic process
which particles have no change in nuclear charge when emitted in nuclear decay?
neutron
the atomic number is equal to the number of…..
protons
the number of protons + neutrons
mass number
If Ecell is a negative number…
cell is electrolytic
If Ecell is a positive number…..
cell is volatile
Ecell=…
Ecell = cathode - anode
a volatile cell converts …
chemical energy to electricity
cation going to cathode
reduction
anion going to anode
oxidation
in a redox reaction, e- moves from…
high potential to low potential
cell potential is the
Ecell
in a oxidation reaction, e- moves from…
low to high potential
O charge is
-2
H charge is
+1
Cl charge is
-1
oxidation state of nitrogen in (NH4)+ is….
-3
Oxidation state of Mn in (MnO4)- is….
+7
the element being reduced is the …
oxidizing agent
oxidation is when the element
gains more pos charge in from reactants to products
oxidation is…
loss of electrons
reduction is….
gain of electrons
reduction is when the element
loses positive charge, becomes more negative in the products
if the cell potential for a reaction is large and positive then the reaction is…
spontaneous
the purpose of the salt bridge in the voltaic cell is…
to maintain neutrality by allowing the flow of ions.
which of the following is the strongest oxidizing agent?
always F2, fluorine.
which is the strongest reducing agent?
Li. because it is always losing electrons.
gibbs formula?
delta G = nFE
nernst equation
E cell = E0 - (RT/ nF) ln Q
nernst equation is used for?
ion concentration
in a concentration cell, the half reactions are…
the same.
electrolyte in lead-acid car battery is
H2SO4
a cell that uses external energy to produce an oxidation-reduction reaction is a ______ cell
electrolytic
reduction occurs at the ______ in both Galvanic and electrolytic cells
cathode.
oxidation occurs at the _______ in both Galvanic and electrolytic cells
anode.
corrosion of metals can be prevented by the following: (but never by salt bridge)
-sacrificial anode
-oxide coating
-paint
delta G = -nFE =…..
-RT*lnK
the F in delta G = -nFE is
96485 C/ mol
E = ….
E = (RT / nF) * ln K
delta G = -RT *…..
ln K
delta G= -RT* ln K
corrosion is..
oxidation / rust.
which radiation is able to penetrate human tissue?
gamma
nuclear fusion is a _______ reaction, reaction by which the ____ produces energy, and not yet practical as an energy source.
thermonuclear
sun
nuclear fission is the
splitting of the nucleus
mass defect and binding energy are related by
e = mc^2
all radioactive decay processes follow
first order reaction kinetics
a cyclotron is a
particle accelerator
the half life of a radioisotope is the…
time required for one half of the atoms to undergo radioactive decay
iodine 131 is transmuted to xenon 131 by
beta emission
polonium 212 is transmuted to lead 208 by
alpha emission
when an atom of cobalt 60 undergoes beta decay the product is
nickel 60
when an atom of U238 undergoes alpha decay the product is
Th 234
when an atom emits gamma radiation, the energy of the nucleus
decreases.
during conversion of uranium 238 to lead 206, X alpha emissions and Y beta emissions occur… what will X and Y equal?
X= 8 Y= 6
all spontaneous processes are…
irreversable
entropy is the ____ in a system
randomness
entropy is a state function.
change in entropy is given by…
S final - S initial
the 2nd law of thermodynamics says
entropy of the universe increases when spontaneous processes occur.
if a forward reaction is spontaneous….
the reverse reaction will be non-spontaneous
a car is being driven from west to east is experiencing…
translational motion.
change in molecule bond length or bond angles, are examples of….
vibrational motion.
when a molecule spins, this is…
rotational motion.
entropy of CO2 increases upon heating because all three types of molecular motion increase (t/f)
true
entropy of neon increases upon heating because all 3 types of molecular motions increase (t/f)
false.
its just a single atom, it will not undergo vibration
which is true:
s = k * w
s = k / w
s = k *ln w
s = k ^ w
S= k * ln w
entropy decreases when…
a gas becomes a solid
at equilibrium free energy, AKA delta G =
0
Gibbs free energy formula
delta G = delta H - T* delta S
if enthalpy is positive and entropy is negative, the reaction is
non spontaneous at all temps.
if volume inc…
entropy inc, and microstates inc
if atoms inc…
microstates inc
if temp inc…
entropy and microstates inc
vibration is
simulstaneous oscillations
if gas moleculs inc…
entropy inc
if no. moles inc, entopy
increases
if molecules become bigger, entropy
increases
what is the value of entropy of a perfect pure crystalline substance at absolute zero
0
what is the third law
cannot reach absolute zero in any number of processes
what happens when NaOH is added to buffer
the NaOH will react with conjugate acid and convert some of it.
what happens when HCl acid is added to buffer
it will react with the conjugate base, and convert some of it.
what will be the ksp expression for dissolution of silver sulfate Ag2SO4
[Ag]^2[SO4]
silver bromide is insoluble in water, but dissolves in aq. ammonia due to formation of…
Ag(NH3)2+ complex to remove silver ions from soln
adding a bromide ion to an aq. soln of ____ will decrease its solubility in water.
BaSO4
Li2CO3
PbS
AgBr
AgBr
find the common ion.
which mixture will form a good buffer,
HCl and KCl
HNO3 and KNO3
HCl and NH4Cl
NH3 and NH4Cl
NH3 and NH4Cl
a buffer is…
weak acid + salt
weak base + salt
strong acid + strong base leads to
-bad buffer
-electrolyte
-dissolves in water
which solution has a better buffer capacity?
1 L solution of 0.5 N NH3 and 0.5M of NH4Cl
this is because this option had higher Molarity than the others.
what is the henderson hasselbach eq?
pH = pKa + log (base / acid)
strong acid + weak base
what is pH
lower than 7
strong base + weak acid
what is pH
higher than 7
bronsted lowry acid
proton H+ donor
bronsted lowry base
proton H+ acceptor
lewis acid
electron pair acceptor
lewis base
electron pair donor
what is the conjugate base of HPO4) -2
PO4)^ -3
conjugate acid of SO4)2-
HSO4)1-
the stronger the acid, the ____ the conjugate base
weaker
acids and bases react to form their ____ conjugate
weaker
conjugate base pair kw =
kw = ka * kb
value of ion product constant for water is
10^-14
all spontaneous processes are
irreversible
which process is NOT spontaneous at 25 deg C?
melting of ice cube
boiling of liquid n2
sublimation of dry ice
freezing of ethyl alcohol
freezing of ethyl alcohol
in spontaneous reaction..
entropy of universe ____
free energy of a system _____
inc
dec
what kind of motion can molecules do, that an atom cant>
a molecule can vibrate and rotate
a single atom cant do either one.
Bolzmanns entropy eq, S=….
S= k ln W
if enthalpy change is pos, and entropy change is neg, reaction is
non spon at all temps
if enthalpy change is neg, and entropy change is pos, reaction is
spontaneous at all temps
what will be the pH change as NaOH is added to an HCl soln?
increase
why will the equilibrium conc of a weak acid equal its initial conc?
because most weak acids of low to moderate concentration undergo very little ionization, often less than 1% in soln, so the extent of ionization can be neglected.
at mid equivalence point,
pH = pKa
2^x = 7
x ln 2= ln 7
O2 is a strong base (t/f)
true
kw=
10^-14
amphoteric
soluble in strong acids/bases, bc they can act either as acids OR bases.
ksp
the []*[] of REACTANTS, not products, no dividing.
