• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/77

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

77 Cards in this Set

  • Front
  • Back
Bronsted-Lowry vs. Lewis acid and base definitions:
B.L.: Acids donate H+ (a proton) bases accept H+ protons

L.A..: acids accept a pair of electrons, and bases donate a pair of e-.
AlCl3 and BF3 are common_________?
Lewis acids.
Nu vs electrophile. which acts as a L.A.?
electrophiles.

nucleophiles attack electrophiles and act as lewis bases.
Amphoteric substance examples:
anything that can act as an acid or a base.
pKa=_________
-log[Ka] same goes for pKb and Kb and Kw( water)
pKa + pKb=______
14
large Ka or small pKa= strong or weak acid??
strong!!

same goes for large Kb for bases and a small pKb
relationship of Ka, Kb and Kw?
Ka*Kb=Kw

Kw is ALWAYS 10^-14 which = [H+][OH-]= 10^-14
For strong acid or strong base the pH or pOH=
-log[strong acid or base] strong acids and bases dissociate 100% in water
Calculating the pH for a weak acids: find the [H+] and that is how I will find the pH
weak acids do not dissociate readily in water. As a general rule if the Ka is less than 1 it can be considered a weak acid.
can an acid or a base be a good electrolyte?
IF it is a strong acid or base meaning 100% dissociation in water it is a good electrolyte.
List the strong acids:
HCl, HBr, HNO3, H2SO4, HI, HClO4, H3O+ is boarder line

HF is not!
Strong bases:
Group 1A hydroxides e.g. NaOH, KOH
NH2-, H-, Ca(OH)2, Ba(OH)2, Sr(OH)2, Na2O, Ca
Oxidation state assignment order:

patterns on periodic table??
Atom
F: -1
H: +1
H w/ a metal: -1
Oxgen (except peroxides): -2
(depends on # of Hydrogens when in peroxide)
Alkali metals: +1 and H is -1 here
Alkaline earth metals: +2
Group V: -3
Group VI: -2
Group Vll: -1
Poly atomic ions:
Hydroxide is OH- ; nitrate is NO3- ; nitrite is NO2- ; chorate is ClO3- ; perchlorate is ClO4- ; chlorite is ClO2- ; hypochlorite is ClO- ; carbonate is CO32- ; bicarbonate is HCO3- ; ammonia is NH3 ; ammonium is NH4+ ; sulfate isSO42-;phosphateisPO43- ;manganateisMnO42-;permanganateisMnO4- ; cyanide is CN-.!
Hydrolysis of a salt. The "salt of a weak acid"
This refers to the conjugate base of that weak acid combined with a cation to form a salt.
e.g.
HCO3-= "weak acid" ; CO3^2-= "conjugate base" and Na2 CO3= "salt of a weak base"

or for a base:
HCO3= "weak base" ; NH4+ = "conjugate acid" ; NH4NO3= "salt of a weak base"
When the salts of weak acids or weak bases dissolve in water one of the ions will undergo hydrolysis to re-form the weak acid or the weak bases. An example:
Na2CO3⇌2Na+ + CO3^2- and then CO3^2- + H2O⇌HCO3- + OH-
All of the salt hydrolysis reactions that have an intermediate compound that carries a negative charge will increase the pH of the solution and if the intermediate has a positive charge it will decrease the pH. I will give an example of each
1) Na2CO3⇌2Na+ + CO3^2- 2) CO3^2- + H2O⇌HCO3- + OH- increases the pH due to OH-

1) NH4NO3⇌NH+ + NO3^2- 2)NH4+ + H2O ⇌ NH3- + H3O+
__________ is the drop by drop mixing of an acid and a base with an indicator.
Titration
If a question states: " a strong base is titrated with a strong acid" which one is being added drop-wise and which is in the beaker? Which solution is referred to as the titrant? the any late??
The subtstance TITRATED WITH the other is the substance that is in the beaker. in this case the strong base. which is also the anylate.
What is the purpose of titration? what is it used for?
It is used as to find a quantitative measurement of the unknown concentration of a identified anylate. also known as "volumetric analysis"
what does one "equivalent" refer to?
the amount of acid or base necessary to produce or consume one mole of H+ ions
How many equivalents of a base can be neutralized by one equivalent of a diprotic acid such as H2SO4?
Two equivalents of base can be neutralized by one equivalent of H2SO4 because each sulfuric acid produces two equivalents of hydrogen ions in solution.!
Know what the graphs should look for titrations with all the different combos:
SA titrated with SB
SB titrated with SA
WA w/ SB
WB w/ SA
Where will the equivalence point be as far a pH goes for each of these?
make sure I can recognize all of these and understand it conceptually!
the ___________ is the midpoint of the nearly vertical section of the graph with SA & SB where the [ ]=[ ]
The Equivalence point/ stoichiometric point.
at this point [titrant]=[analyte]
And the pH at the equivalence point is obviously 7 ( H+ concentration = OH- conc.
With titration of a WA w/ a SB or WB w/ a SA the equivalence point is still the same definition: the midpoint of the nearly vertical section of the graph and at that point the [titrant]=[analyte] also. HOWEVER....
because the acid and base are not both strong, the H+ conc. does not equal the OH- conc. which also tells us that the pH will not be 7 at this point!
What is the half equivalence point? here the pH =_____
It is the midpoint of the nearly horizontal section of the graph.
pH=pKa and also [HA]=[A-] at the half equivalence point!
It is the midpoint of the nearly horizontal section of the graph.
pH=pKa and also [HA]=[A-] at the half equivalence point!
If you wanted to calculate the acid dissociation constant and you were given information on a graph what would you locate to find the pKa?
the half equivalence point!!
Do strong acids and strong bases have half-equivalence points? why or why not?
They do not!! because of there will not really be a point where [HA]=[A-] because almost immediately after adding HA 100% has been changed to A-.
Are indicators used in titration weak acids or weak bases.
They change color as they dissociate from ____ into____and ____.
They are weak bases.
change colors as they dissociate from HA into H+ and A-.
To set up a titration you must know before hand the:
approximate pH of your equivalence point.
then select an indicator that will change color at that pH

the indicator never impacts pH.
What is the difference between the equivalence point and the end point?
the equivalence point is where [titrant]=[analyte].

The end point is simply the point when the indicator causes the color change. The extent of the relationship depends entirely on the indicator used.
Which indicator should be used to identify the equivalence point for the titration of a weak base with a strong acid?
One that is below 7. as close to the expected equivalence point as possible.
A buffer solution contains a weak acid and a weak base or often the conjugates of each other.
There is an equilibrium between the weak acid and its conjugate base or the weak base and its c.a.
What is the nearly horizontal area surrounding the half-equivalene point called?

does adding a large amount of titrant have affect on the pH?
The buffer region


it will have little effect.
What is one example of a natural buffer solution found in nature?
blood.
The Henderson-Hasselbach equation which is:
-can demonstrate pH=pKA
-describes the derivation of pH as a measure of acidity
-used to calculate pH of a buffer solution
-pH of acid/base reactions
and the isoelectric point of proteins
At the half-equivalence point the concentrations of HA and A- are equal. Therefore, the ratio of [A-]/[HA] must be one. When we plug this into the H-H equation we get: pH = pKa + log(1). The log of unity is zero, so this term falls out, demonstrating that
At the half-equivalence point the concentrations of HA and A- are equal. Therefore, the ratio of [A-]/[HA] must be one. When we plug this into the H-H equation we get: pH = pKa + log(1). The log of unity is zero, so this term falls out, demonstrating that pH = pKa at the half-equivalence point.!
There are seven clues that will help me realize that it is a buffer problem! name 4 major ones on the back of this card
watch for WA or bases
1-when it says any time an acid or base is added to a solution and the "pH done not change much or slightly"
2-Watch for equimolar amounts! [HA]=[A-]
3- watch for "half-equivalence point"!
4- watch for pH= pKa
cell potential (a.k.a. cell EMF or E knot) is the sum of____.

half reactions always come in______.
sum of the electrical potentials for the two half-reactions that make up an electrochemical cell.

always come in pairs! the reduction reaction and the oxidation. usually only the reduction half reactions are given in tables so the oxidation half reaction is just the negative of E knot for that reduction half reaction!
A species with a positive E knot is more likely to_______ electrons and be__________ than are hydrogen ions because 2H+ + 2e-→H2 = E knot 0.00V
gain electrons and be reduced

negative E knot are less likely to gain electrons
what is a biological connection or example of cell potentials:
O2(g) + 4H+ (aq) + 4e- → 2 H2O (l) = 1.23 V This is the last step of the Electron transport chain.
A Galvanic cell converts ________ to _________
convert chemical energy into electrical energy by redox reactions or reduction potential differences between two metals.
convert chemical energy into electrical energy by redox reactions or reduction potential differences between two metals.
What is the purpose of a salt bridge?
conducts the ions (both the metal-A cations from one solution, and the anions from the other solution), which balances the charges of the solutions and thereby allows the reaction between metal A and metal B to continue without opposition.
Does reduction always occur at the cathode or anode?
At the cathode. Cathode = (+) - gain of electrons. attracts cations!
Anode = (-) loss of electrons (oxidation) attracts anions!
Copper readily oxidizes zinc what is the electrochemical reaction for this?
Zn + Cu^2+ → Zn^2+ + Cu

the zinc electrode is dissolved and the copper is deposited on the copper electrode.
Cell potential for a Galvanic cell is always_______?
positive.
A properly set up Galvanic cell will always produce_____?
always produce current. e- flow from lower reduction potential to higher
If a question gives you a metal at the cathode and asks which other metal it can combine with at the anode for copper to be reduced the other metal must_______
have a lower reduction potential. Be less able to reduce.
What is the difference between and electrolytic cell and a galvanic cell??
electrolytic cell is basically a galvanic cell in which external voltage is applied, forcing the electron flow in the opposite direction.
Does the location of oxidation and reduction change when comparing galvanic and electrolytic cells?
NO!! oxidation still occurs at the anode and reduction still occurs at the cathode.
-the species with the LOWER reduction potential will be reduced in an electrolytic cell. and the cell potential will ALWAYS be negative.
In an electrolytic cell, the sum of the externally applied voltage (V-battery) and the negative cell potential (E-knot cell) must be_________?
must be positive!
Galvanic cell reactions occur spontaneously, electrolytic do not. They have the ability to decompose normally stable or inert chemical compounds in a solution.
What is a concentration cell and when is it used?
two equivalent half cells with the same material only differing in concentration. so it is at non standard conditions.
use the Nernst Equation
Nernst equation:
E= E naught - (.06/n) * Lower/higher ( n= moles of e- transferred)
The relationship between free energy and Chemical Energy: - what is the equation used?
∆G=-nFE° where n is the number of moles transferred in the balanced redox run. ad F is Faradays constant.
From the equation ∆G=-nFE° we learn:
+E°= negative ∆G= spontaneous rxn.
Faradays constant is the charge on__________?
on one mole of electrons.
How would you calculate Faradays constant for 1 mole of electrons?
Faraday’s constant is the charge on one mole of electrons. One mole of electrons is 6.022 x 1023 electrons. Each electron has a charge of 1.6 x 10-19C. Therefore, the charge on one mole of electrons is: (6 x 1023)(1.6 x 10-19) = 9.6 x 104 C/mol.
The Faraday has since been replaced by the_______?
Coulomb.
What is a Farad? and what units is it in?
A Farad is a unit of capacitance. ( a summary unit similar to a Newton)

1 Farad is 1C^2 * s^2 / m^2 * kg.
A Farad is the amount of capacitance necessary to hold 1 _____ of a charge on a capacitor with a potential difference (voltage) of _____.
I Coulomb of charge,
1 volt
How do we determine the pKa of DOOH when we know the Ka is 2.0 * 10^-5?
if the mantissa is one we can just directly flip the exponent sign and that is the pKa. But if it is somewhere in between like in this case of 2.0 we know that it is barely less than 5. (2/10th) to be exact. so the pka is 4.8
which of these has the lowest Ka:
HClO4
HClO3
HClO2
HClO
HClO because it has the least stable conjugate base, least amount of resonance structures because it has the least amount of double bonds and Oxygens. YIA!!
which of these is nitrous acid and which is nitric acid?
which dissociates 100% in water?
HNO3

HNO2
HNO3 is nitric

HNO2 is nitrous
In real vs ideal gases, is volume more or less than predicted in real gases?
It is more than ideal because in ideal gases we assume that they don't take up any space when in reality they do.
Relationship between Freezing point and melting point.
it is very important to realize that melting point and freezing point are exactly the same thing. You might think of freezing point as the temperature at which a liquid changes into a solid, but the value measured for mp or fp is simply a temperature, which indicates no direction. For ANY substance. MP=FP
phase diagram
phase diagram of water
phase diagram of water
Difference in triple point vs critical point:
At the triple point all three phases are present. At the critical point none of the original three phases are present, only the new “supercritical fluid” phase.!
the only time vapor pressure of a solvent increases when you add a volatile solute is:
if the vapor pressure of the solute is higher than the solvent otherwise it will decrease vapor pressure. and non-volatile solvents always decreases VP.
The solubility of a gas in a liquid is directly proportional to what?
The partial pressure of that gas over that liquid.
Does increasing the temperature in a liquid increase or decrease the solubility of the gas?
Increase temp. decreases solubility and decreased temp increases solubility!!
do polar and non polar gases form homogenous mixtures or separate?
easily form homogenous mixtures
Increasing the Vapor pressure of gas X over a liquid will increase or decrease the solubility of the gas X in that liquid?
It will increase the solubility!
when does a liquid begin to boil?
A liquid boils when the vapor pressure of that liquid is equal to atmospheric pressure.!
Because of the Van't Hoff factor with BP elevation and FP depression which molecule would have a lower FP?
1.5 moles of NaCl or or 1.25 moles of CaCl2?
FP depression: ∆T=kf(m)(i)
BP elevation : ∆T=kb(m)(i)
CaCl2 1.25 * 3= 3.75
what does a negative heat of solution tell us?
A negative heat of solution tells us that the dissolution releases heat. In order for this to occur, the solvent-solute bonds must be relatively stronger than the solvent-solvent and solute-solute bonds that had to be broken in order to dissolve the solute into the solvent.
What is the common ion effect?
Addition of a common ion will cause precipitation. If a spectator ion is added no precipitation will result.
FeCl3(s) ↔ Fe3+(aq) + 3Cl-(aq). adding NaCl will cause the reaction to move to the left and precipitate will form!
solubility general rules:
soluble: nitrate, ammonium, and all Group 1A

insoluble: Unless paired with something from the soluble group: carbonate, phosphate, Ag, Hg, and Pb.