Search found 76 matches
- Sun Mar 18, 2018 2:13 am
- Forum: General Science Questions
- Topic: Extensive and Intensive
- Replies: 1
- Views: 492
Extensive and Intensive
Aside from standard cell potential is there any other intensive things?
- Sat Mar 17, 2018 1:32 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: wmax
- Replies: 4
- Views: 793
wmax
is wmax equal to ΔG° or just ΔG?
- Tue Mar 13, 2018 8:19 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: arrhenius equation
- Replies: 1
- Views: 294
arrhenius equation
when do you use this equation?
- Tue Mar 13, 2018 8:18 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: arrhenius equation
- Replies: 3
- Views: 408
arrhenius equation
when do you use this equation?
- Tue Mar 13, 2018 7:42 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Isobaric
- Replies: 1
- Views: 376
Isobaric
for an isobaric equation, since delta p = 0, is the internal energy = delta h?
- Tue Mar 13, 2018 7:36 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Bomb Calorimeter
- Replies: 2
- Views: 626
Bomb Calorimeter
I made a note that says bomb calorimeter = constant volume, how would you find the internal energy? does constant volume mean delta v = 0?
- Mon Mar 12, 2018 11:37 am
- Forum: *Alcohols
- Topic: functional groups [ENDORSED]
- Replies: 4
- Views: 1765
functional groups [ENDORSED]
will we need to know functional groups for the final?
- Wed Mar 07, 2018 12:50 am
- Forum: General Rate Laws
- Topic: What equation is this?
- Replies: 1
- Views: 276
What equation is this?
what equation is this and when do you use it?
ln (k1/k2) = Ea/R (1/T2 - 1/T1)
ln (k1/k2) = Ea/R (1/T2 - 1/T1)
- Wed Mar 07, 2018 12:48 am
- Forum: General Rate Laws
- Topic: Rate of Formation/Concentration [ENDORSED]
- Replies: 1
- Views: 261
Rate of Formation/Concentration [ENDORSED]
When do you use rate of formation and/or rate of concentration?
- Wed Mar 07, 2018 12:34 am
- Forum: Zero Order Reactions
- Topic: zeroth order rate
- Replies: 4
- Views: 734
zeroth order rate
what is the zeroth order rate? is it -k?
- Fri Mar 02, 2018 11:16 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius Reaction
- Replies: 6
- Views: 796
Arrhenius Reaction
Did we already go over arrhenius reaction or are we going to?
- Wed Feb 28, 2018 10:09 am
- Forum: First Order Reactions
- Topic: Derivation
- Replies: 8
- Views: 999
Derivation
are we going to have to derive or integrate the 1st or 2nd order for test 3 or the final?
- Tue Feb 20, 2018 4:51 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Cell Potential
- Replies: 9
- Views: 3184
Cell Potential
when do you use each of the equations and what is the difference?
E = E° -RT/nF * ln Q
E = E° -0.05916 V / n * log Q
E = E° -RT/nF * ln Q
E = E° -0.05916 V / n * log Q
- Tue Feb 20, 2018 4:46 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Standard cell potential
- Replies: 1
- Views: 293
Standard cell potential
when figuring out which reaction to flip so that you get the highest cell potential, do you add or subtract the two cell potentials?
- Fri Feb 16, 2018 2:01 am
- Forum: Balancing Redox Reactions
- Topic: Cl2 and Cl -
- Replies: 2
- Views: 1362
Cl2 and Cl -
if Cl is just 1- charge how come just making Cl -, 2Cl - doesn't make the charges cancel?
- Wed Feb 14, 2018 11:20 am
- Forum: Calculating Work of Expansion
- Topic: irreversible work [ENDORSED]
- Replies: 3
- Views: 488
irreversible work [ENDORSED]
for irreversible expansions, do you use you use w= -p delta v?
- Tue Feb 13, 2018 8:57 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: W
- Replies: 3
- Views: 788
W
can someone please explain in simple terms and give examples of how to find w for boltzmann equation
- Tue Feb 13, 2018 6:50 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: PV = nRT
- Replies: 6
- Views: 939
PV = nRT
when do you use PV = nRT?
- Tue Feb 13, 2018 6:41 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Spontaniety
- Replies: 2
- Views: 486
Spontaniety
does being spontaneous have anything to do with speed?
- Tue Feb 13, 2018 6:39 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: reversible and isothermal
- Replies: 1
- Views: 319
reversible and isothermal
if something is reversible and isothermal, i know the total internal energy equals 0, therefore q = -w, but what else should i know about this?
- Tue Feb 13, 2018 11:37 am
- Forum: Calculating Work of Expansion
- Topic: Work
- Replies: 1
- Views: 319
Work
For clarification, If a piston compresses does that mean work is positive? And if it expands does that mean work is negative?
- Fri Feb 09, 2018 10:52 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: delta g
- Replies: 2
- Views: 322
Re: delta g
delta g r*
- Fri Feb 09, 2018 10:51 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: delta g
- Replies: 2
- Views: 322
delta g
what's the difference between delta g, and delta r r, as well as delta g r knot?
- Fri Feb 09, 2018 10:40 am
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Review Sessions
- Replies: 1
- Views: 321
- Tue Feb 06, 2018 9:21 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: W
- Replies: 3
- Views: 373
W
how do you find W?
- Tue Feb 06, 2018 8:56 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Kelvin
- Replies: 4
- Views: 529
Kelvin
Do you always have to use kelvin with regards to temperature?
- Tue Feb 06, 2018 8:49 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: entropy chnage
- Replies: 1
- Views: 265
entropy chnage
in question 9.5 why is it -50 j.k? can someone explain where the negative came from
- Tue Feb 06, 2018 8:31 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: monatomic ideal gasses
- Replies: 2
- Views: 370
monatomic ideal gasses
what are examples of monatomic ideal gasses?
- Mon Feb 05, 2018 11:17 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: temperature
- Replies: 5
- Views: 550
temperature
for measuring temperature in kelvin on the test do we use 273.15 or just 273?
- Mon Jan 29, 2018 2:10 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneity of a reaction
- Replies: 2
- Views: 366
Spontaneity of a reaction
In class we discussed rxn or physical change between the change in s and change in h, Dr. Lavelle mentioned that when delta s is negative and delta h is positive it is never spontaneous but the reverse is. does this mean that the reverse of the other 3 would not be spontaneous?
- Tue Jan 23, 2018 11:52 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: calorie and Calorie
- Replies: 2
- Views: 238
Re: calorie and Calorie
What is 1 calorie?
- Tue Jan 23, 2018 11:22 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpies
- Replies: 4
- Views: 430
Bond Enthalpies
Is bond enthalpies the sum of reactions minus the sum of products or the sum of products minus the sum of reactants?
- Tue Jan 23, 2018 11:15 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: calorie and Calorie
- Replies: 2
- Views: 238
calorie and Calorie
do we need to know the conversions for calorie and Calorie or will they be provided?
- Tue Jan 23, 2018 9:56 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: mass in q = m(c) delta t
- Replies: 5
- Views: 892
mass in q = m(c) delta t
when must you covert the g to moles when using the equation for specific heat?
- Mon Jan 22, 2018 11:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 3 Test Topic is endorsed
- Replies: 37
- Views: 4738
Re: Week 3 Test Topic is endorsed
will internal energy be on the test?
- Fri Jan 19, 2018 1:51 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy at constant pressure and volume [ENDORSED]
- Replies: 3
- Views: 283
Enthalpy at constant pressure and volume [ENDORSED]
with regards to enthalpy, are we expeced to be able to calculate the heat released at a constant volume or pressure? also what is this 5/2R and 3/2 R business?
- Fri Jan 19, 2018 1:37 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capcity for Water
- Replies: 8
- Views: 637
Heat Capcity for Water
How do you know which heat capacity to use for water?
- Fri Jan 19, 2018 1:09 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Internal Energy/Open System
- Replies: 3
- Views: 324
Internal Energy/Open System
What are the three ways you can increase the internal energy of an open system?
- Fri Jan 19, 2018 1:09 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Internal Energy/Open System
- Replies: 4
- Views: 558
Internal Energy/Open System
What are the three ways you can increase the internal energy of an open system?
- Wed Jan 17, 2018 10:59 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Breaking or forming
- Replies: 5
- Views: 572
Re: Bond Breaking or forming
yeah that makes sense, so my follow up question would be after drawing the electron configurations how could you tell if a bond is broken or formed like what would it look like?
- Wed Jan 17, 2018 10:22 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Breaking or forming
- Replies: 5
- Views: 572
Bond Breaking or forming
When looking at a rxn, is there another way aside from looking at the delta h to know if a bond is forming or breaking?
- Wed Jan 17, 2018 10:19 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Cm
- Replies: 3
- Views: 360
Cm
what is Cm in the equation q = n (delta t) (Cm)?
- Sun Jan 14, 2018 4:31 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: q and w
- Replies: 5
- Views: 622
Re: q and w
soooo my follow up question would be when do you know when work is done on a system vs done by a system?
- Sun Jan 14, 2018 4:23 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond and Standard Formation Enthalpies
- Replies: 1
- Views: 204
Bond and Standard Formation Enthalpies
with bond enthalpies and standard formation enthalpies, i know they're are equations you must follow, what are they and what is each part of the equation?
- Sun Jan 14, 2018 4:22 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: q and w
- Replies: 5
- Views: 622
q and w
can someone clarify what q and w are as well as how can you tell if they will be positive or negative?
- Sun Jan 14, 2018 4:17 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond Enthalpies and the use of kJ
- Replies: 1
- Views: 180
Bond Enthalpies and the use of kJ
When do you use kJ.mol, kj. Cº or just kj?
- Sun Dec 10, 2017 12:22 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH from pka
- Replies: 3
- Views: 574
Re: Calculating pH from pka
like if it asks for the ph but gives you the pka how do you find ph?
- Sun Dec 10, 2017 12:21 am
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH from pka
- Replies: 3
- Views: 574
Re: Calculating pH from pka
would you find the negative log of the pka to find your ka?
- Sat Dec 09, 2017 11:57 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pH from pka
- Replies: 3
- Views: 574
Calculating pH from pka
If you are given a pka, how do you go about finding the pH?
- Sat Dec 09, 2017 2:50 pm
- Forum: Properties of Light
- Topic: Speed of light wavelength equation [ENDORSED]
- Replies: 4
- Views: 723
Speed of light wavelength equation [ENDORSED]
When do you use the c = wavelength x frequency?
- Fri Dec 08, 2017 2:03 pm
- Forum: Ionic & Covalent Bonds
- Topic: Memorization of Electronegativity
- Replies: 6
- Views: 951
Memorization of Electronegativity
Do we need to memorize the actual electronegativity chart as far as values or is just knowing the basic trend enough?
- Wed Dec 06, 2017 9:18 pm
- Forum: Ionic & Covalent Bonds
- Topic: ionic character
- Replies: 1
- Views: 245
ionic character
what does “ionic character” mean?
- Wed Dec 06, 2017 9:17 pm
- Forum: Ionic & Covalent Bonds
- Topic: polarizing power
- Replies: 1
- Views: 328
polarizing power
what does “polarizing power” mean? Also what does “more polarizable ion” mean?
- Tue Dec 05, 2017 2:54 pm
- Forum: Identifying Acidic & Basic Salts
- Topic: HClO2
- Replies: 1
- Views: 754
HClO2
For HClO2 why does it prefer the second O to be connected to the Cl instead of making a chain like Cl-O-O-H?
- Tue Dec 05, 2017 1:04 am
- Forum: Conjugate Acids & Bases
- Topic: Acids and Bases [ENDORSED]
- Replies: 8
- Views: 2393
Re: Acids and Bases [ENDORSED]
I honestly don't know, but I doubt it. I was told to memorize them by my plf. There's also a list of strong bases. LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH)2, Sr(OH)2, and Ba(OH)2
- Tue Dec 05, 2017 12:50 am
- Forum: Conjugate Acids & Bases
- Topic: Acids and Bases [ENDORSED]
- Replies: 8
- Views: 2393
Re: Acids and Bases [ENDORSED]
there is a list of strong acids, if it is not one of those, it is considered weak. the list of strong acids include HCl, HBr, HI, HNO3, HClO3, HClO4, H2SO4
- Mon Nov 27, 2017 5:07 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Backward Reaction
- Replies: 2
- Views: 561
Backward Reaction
When do you know the reaction is going backwards instead of forwards ?
- Mon Nov 27, 2017 2:17 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2973407
Re: Post All Chemistry Jokes Here
What is your LiFe composed of?
-Lithium and iron
-Lithium and iron
- Thu Nov 23, 2017 1:29 pm
- Forum: Hybridization
- Topic: Pi Bonds vs. Sigma Bonds
- Replies: 7
- Views: 1050
Re: Pi Bonds vs. Sigma Bonds
a single bond has a sigma bond, a double bond has a sigma bond and a pi bond, and a triple bond has a sigma bond and 2 pi bonds
- Mon Nov 20, 2017 1:29 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lewis structure and Vsper
- Replies: 2
- Views: 277
Lewis structure and Vsper
when drawing a lewis structure if we know the molecular shape of it from vsper do we draw it accordingly? or are we allowed to place the bonds andywhere around the central atom?
- Sat Nov 18, 2017 11:23 am
- Forum: Administrative Questions and Class Announcements
- Topic: Homework [ENDORSED]
- Replies: 1
- Views: 300
Homework [ENDORSED]
Are we allowed to do chapter 4 for homework due next week or do we do chapter 17?
- Wed Nov 15, 2017 12:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Regions of electron density
- Replies: 4
- Views: 497
Regions of electron density
Does a lone pair count as a region of e-density when determining the shape?
- Thu Nov 09, 2017 12:40 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Negative Sign in Bohr's Equation
- Replies: 3
- Views: 10905
Negative Sign in Bohr's Equation
What is the significance/origin of the negative sign in Bohr's equation: En=-hR/n^2
- Wed Nov 08, 2017 11:39 pm
- Forum: Lewis Structures
- Topic: Exceptions
- Replies: 4
- Views: 483
Re: Exceptions
chromium and copper
- Wed Nov 08, 2017 11:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: Polar vs. Non-polar
- Replies: 11
- Views: 1000
Polar vs. Non-polar
How can you tell if a compound is polar or non polar?
- Mon Nov 06, 2017 8:29 am
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity [ENDORSED]
- Replies: 6
- Views: 1386
Re: Electron Affinity [ENDORSED]
Michael Cheng 1B wrote:What is the difference between electron affinity and electronegativity?
Electronegativity is how well an atom can attract electrons, while electron affinity is how much energy an atom releases when an electron is added.They both share the trend of increasing from bottom to top and left to right.
- Mon Nov 06, 2017 8:18 am
- Forum: Administrative Questions and Class Announcements
- Topic: Homework for this week [ENDORSED]
- Replies: 2
- Views: 323
Homework for this week [ENDORSED]
Is the homework for this week chapter 3 or 4?
- Thu Nov 02, 2017 1:37 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Orbitals
- Replies: 1
- Views: 179
Re: Orbitals
the l value is n-1, what you are talking about is ml, and it is -l to +l
- Wed Nov 01, 2017 11:32 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Unpaired Electrons [ENDORSED]
- Replies: 3
- Views: 493
Re: Unpaired Electrons [ENDORSED]
you would need to know how many total electrons there are in the atom, what is the last subshell being used, and how many electrons can that subshell hold. Then in the last subshell, you put one arrow in each of the orbitals and then come back around to fill them. for example, if it was oxygen, ther...
- Wed Nov 01, 2017 11:19 pm
- Forum: Trends in The Periodic Table
- Topic: Trends in the periodic table
- Replies: 3
- Views: 606
Re: Trends in the periodic table
electron affinity increases from left to right and increases from bottom to top, thereby making fluorine the most electron affinitive. (if that's a word)
- Wed Oct 25, 2017 4:21 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration writing
- Replies: 8
- Views: 813
Re: Electron Configuration writing
When dealing with an atom that is an ion for example S^2- is it incorrect to write it in condensed from as [Ar]?
- Wed Oct 25, 2017 12:36 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration writing
- Replies: 8
- Views: 813
Re: Electron Configuration writing
Yesterday we were trying to write rhodium’s electron configuration and we got 2 different answers, so then we looked at the lavelle periodic table and clarified which one is correct, so for clarification, is rhodium an exception like cooper and chromium?
- Mon Oct 23, 2017 12:08 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electronic Configuration for d-block elements [ENDORSED]
- Replies: 9
- Views: 1335
Re: Electronic Configuration for d-block elements [ENDORSED]
So for elements after 20 would you fill up the 4s and then return back to 3d or fill up 3D and then proceed?
- Mon Oct 16, 2017 3:07 pm
- Forum: Properties of Light
- Topic: Quiz #2 References [ENDORSED]
- Replies: 4
- Views: 557
Re: Quiz #2 References [ENDORSED]
Do we have to print out the reference sheet ourselves or will it be given in class?
- Thu Oct 05, 2017 1:14 am
- Forum: SI Units, Unit Conversions
- Topic: Sig Figs
- Replies: 12
- Views: 3224
Re: Sig Figs
If it was .5060 and you wrote it in scientific notation, It would be 5.060 x 10^-1 so would there be 3 or 4 sig figs?
- Thu Oct 05, 2017 1:10 am
- Forum: SI Units, Unit Conversions
- Topic: Limiting Reagents [ENDORSED]
- Replies: 8
- Views: 1046
Re: Limiting Reagents [ENDORSED]
It could also ask instead of limiting reactant, which one is the excess and how much excess is there? Or it could ask how many moles can be produced?