Search found 22 matches
- Sun Mar 19, 2017 9:06 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3890445
Re: Post All Chemistry Jokes Here
I saw someone run away with my gold, so I shouted "Hey! AU!"
- Sun Mar 12, 2017 10:01 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: delta G double dagger
- Replies: 1
- Views: 7658
Re: delta G double dagger
Delta G double dagger depends on the energy difference between the reactants and the transition states and regular delta G is the energy difference between the reactants and the products. I'm not aware of any equation that relates them
Hope this helps!
Hope this helps!
- Sun Mar 12, 2017 9:45 pm
- Forum: *Alcohols
- Topic: more than one functional group [ENDORSED]
- Replies: 2
- Views: 770
Re: more than one functional group [ENDORSED]
We do not need to know how to name organic molecules with more than one functional group. Here's another link that says the same thing near the bottom of the thread https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=89&t=13856&p=57839&hilit=functional+groups&sid=73b4fecbaca08840fde3...
- Sun Feb 26, 2017 9:42 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Which electrode to use?
- Replies: 2
- Views: 631
Re: Which electrode to use?
If there is not an electrode given, pt electrodes are inert and work perfectly. I don't think there's a situation when either of them would be favored.
Hope this helps!
Hope this helps!
- Sun Feb 19, 2017 9:08 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3890445
Re: Post All Chemistry Jokes Here
Did you know that you can cool yourself to -273˚C and still be 0k?
- Sun Feb 12, 2017 9:48 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Heat Capacity
- Replies: 3
- Views: 633
Re: Heat Capacity
It depends on what is given on equation sheet and what the specific problem is asking for. If only one value is given, you can always convert from grams to moles or vice versa.
Hope this helps!
Hope this helps!
- Sun Feb 12, 2017 9:44 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: When to use reversible work equation?
- Replies: 1
- Views: 543
Re: When to use reversible work equation?
As far as I'm aware, all isothermal compressions are reversible, so you can use the reversible equation for all isothermal situations. I assume that Dr. Lavelle will explicitly state irreversible/reversible(isothermal) situations in the question.
- Sun Feb 12, 2017 9:39 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy @ 0K
- Replies: 2
- Views: 587
Re: Entropy @ 0K
From my understanding, molecules that are not diatomic will have more molar entropy. However, I'm not entirely clear on the explanation for this except for the fact that the mixed element molecule is technically more complicated.
- Sun Feb 05, 2017 9:02 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anode/Cathode
- Replies: 4
- Views: 780
Re: Anode/Cathode
The salt bridge's purpose is to prevent charge build up in the cathode. So, when ions build up in the cathode solution, the can be transferred over through the salt bridge to the anode to keep the redox reaction going. I hope this helps!
- Mon Jan 23, 2017 10:40 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3890445
Re: Post All Chemistry Jokes Here
Got mole problems? Call Avogadro at 602-1023.
- Sun Jan 15, 2017 3:20 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Capacities [ENDORSED]
- Replies: 3
- Views: 767
Re: Heat Capacities [ENDORSED]
The specific heat capacity is measured in grams or kilograms, as opposed to the molar heat capacity which is measured in moles.
- Sun Dec 04, 2016 11:47 am
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: 2015 Final Q7A
- Replies: 1
- Views: 778
Re: 2015 Final Q7A
I actually think it could be either reason, but when I'm indicating that something is more acidic, in my opinion it is more logical to say that there is an excess of acid.
I hope this helps!
I hope this helps!
- Mon Nov 21, 2016 11:28 am
- Forum: Bronsted Acids & Bases
- Topic: Protonation [ENDORSED]
- Replies: 2
- Views: 675
Re: Protonation [ENDORSED]
To add on, ionization refers generally to a change in number of electrons (aka a plus or minus charge on an element) and dissociation generally refers to the separation and ionization of a compound. I hope this helps!
- Tue Nov 15, 2016 9:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: calculating Kc [ENDORSED]
- Replies: 3
- Views: 717
Re: calculating Kc [ENDORSED]
I won't solve the problem for you, but the idea of this problem is that it gives the initial and final concentrations of BrCl, and therefore you can find the concentrations of the other products at equilibrium and find Kc.The material that will be covered on quiz 3 is only the basics of equilibrium....
- Mon Nov 14, 2016 11:32 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Concentration Units [ENDORSED]
- Replies: 3
- Views: 1654
Re: Equilibrium Concentration Units [ENDORSED]
Just to clarify further, you do not need to put unit n/V or M inside brackets when calculating K or Q for aqueous solutions because the brackets indicate that you are calculating K/Q based on molarity. For pressure on the other hand, when you put the values into the K/Q calculation, it would be wise...
- Sun Nov 13, 2016 12:26 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Difference between Pressure and compression/expansion?
- Replies: 5
- Views: 4911
Re: Difference between Pressure and compression/expansion?
Theoretically, if the gas has room to expand, the pressure would decrease. If the volume decreases and the gas is compressed, the pressure would increase. This is all based off of the ideal gas equation of PV=nRT, where P and V are inversely related.
- Mon Oct 31, 2016 10:16 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shapes
- Replies: 6
- Views: 1151
Re: Shapes
To add on, even though we do consider the lone pairs as fields of electron density that affect the bond angles and shape of a molecule, we only consider the position of the bound electron pairs when we name the shape of a molecule.
- Wed Oct 26, 2016 9:37 am
- Forum: General Science Questions
- Topic: Past Quizzes (2)
- Replies: 1
- Views: 822
Re: Past Quizzes (2)
Some of the preparation quizzes cover chapter 4 information, so we won't be tested on concepts we haven't discussed yet. Check out this link for more information https://lavelle.chem.ucla.edu/forum/viewtopic.php?f=30&t=16106 I don't have any good memorization tips, but the website ptable.com hel...
- Mon Oct 17, 2016 9:09 am
- Forum: *Shrodinger Equation
- Topic: Still confused on the definition of shrodinger's equation?
- Replies: 1
- Views: 593
Re: Still confused on the definition of shrodinger's equation?
As far as I know, Schrodinger's equation is only useful to us in the sense that the equation describes wave functions. Then, the wave function describes electrons in an atom and therefore orbitals the electrons are in. I don't believe we'll be doing any calculations with it.
Hope this helps!
Hope this helps!
- Mon Oct 10, 2016 10:45 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration [ENDORSED]
- Replies: 4
- Views: 951
Re: Electron Configuration [ENDORSED]
When we determine values for ml , the values possible are integers within -l and +l. So for example, when l=2, the possible ml values will be -2(which is -l), -1, 0, +1, and +2(which is +l).
Hope this helps!
Hope this helps!
- Mon Oct 03, 2016 4:32 pm
- Forum: Einstein Equation
- Topic: Simplifying De Broglie's wavelength equation [ENDORSED]
- Replies: 1
- Views: 783
Re: Simplifying De Broglie's wavelength equation [ENDORSED]
You're right about the units for joules, but the units for Planck's constant are J x s. So therefore you end up with (kg x m^s x s^-2 x s)/(kg x m x s^-1), and you end up with wavelength in meters.
- Fri Sep 30, 2016 8:29 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Formula [ENDORSED]
- Replies: 3
- Views: 855
Re: Rydberg Formula [ENDORSED]
I think that you can use the wavelength to determine the first n value. The wavelength indicates either the Balmer series or the Lyman series and each series has a specific n1 value. These values are in the text on pg 8 of the textbook(6th edition).