Search found 40 matches
- Fri Mar 15, 2019 9:03 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
- Fri Mar 15, 2019 9:02 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
- Fri Mar 15, 2019 9:01 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
A chemistry lab is a lot like a party! Some drop acid, some drop the bass.
- Mon Mar 04, 2019 10:07 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
- Mon Mar 04, 2019 10:05 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
Chemistry is a lot like cooking, only you really shouldn't lick the spoon.
- Mon Mar 04, 2019 10:04 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
Why do chemists learn about ammonia first?
It's pretty basic, really.
It's pretty basic, really.
- Sat Feb 23, 2019 10:01 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
- Sat Feb 23, 2019 9:59 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
Are you full of beryllium, gold, and titanium? Because you're Be-Au-Ti-ful!
- Sat Feb 23, 2019 9:57 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
If a king farts, is it a noble gas?
- Thu Feb 14, 2019 10:46 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
I can't trust atoms anymore, I heard they make up everything.
- Thu Feb 14, 2019 10:42 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: intensive and extensive
- Replies: 2
- Views: 567
Re: intensive and extensive
An extensive property means that the value you get depends on how much you have of it, for example, volume is an extensive property because how many liters, mL, etc. you have of it determines the volume. On the other hand, intensive properties are constant, no matter how much you have of it. E.g. Wa...
- Thu Feb 14, 2019 10:39 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
- Replies: 49
- Views: 11742
Re: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
Thanks again Lyndon for the practice exam! Helped a lot! C:
- Mon Feb 11, 2019 12:12 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Midterm #1 14B
- Replies: 17
- Views: 2209
Re: Midterm #1 14B
Are worksheets from other TA's/LA/UA's available on the chemistry community?
- Mon Feb 11, 2019 12:10 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Midterm 2019
- Replies: 9
- Views: 900
Re: Midterm 2019
The midterm covers everything up to last Friday's lecture, so Chemical Equilibrium, Acid and Base Equilibria, Thermochemistry, Thermodynamics to the end of entropy, but not including Gibb's free energy.
- Mon Feb 11, 2019 12:08 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Bond enthalpies
- Replies: 10
- Views: 920
Re: Bond enthalpies
I think knowing them will be helpful, but the BDE would probably be given on the test/in a table maybe? That's how it's been for the examples we worked on in class and such.
- Mon Feb 11, 2019 12:01 am
- Forum: Administrative Questions and Class Announcements
- Topic: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
- Replies: 49
- Views: 11742
Re: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
Thanks for posting this again, Lyndon! See you tomorrow at the review session!
- Sat Feb 02, 2019 9:25 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
What is Cesium and Iodine's favorite drama?
CSI C:
CSI C:
- Sat Feb 02, 2019 9:24 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
An acid with an attitude is jut an a-mean-o-acid
- Sat Feb 02, 2019 9:22 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
I told a chemistry joke on here once, but I didn't get a reaction :C
- Sat Jan 12, 2019 12:06 am
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Changing Pressure
- Replies: 6
- Views: 567
Re: Changing Pressure
Pressure and volume have an inverse relationship, therefore if you want to change the pressure within the reaction you have to change the volume of the container. To increase the pressure, volume must decrease, so that particles within the container are more squished together, creating greater press...
- Sat Jan 12, 2019 12:01 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Calculating Kc
- Replies: 4
- Views: 473
Re: Calculating Kc
Though the concentrations don't affect Kc, the coefficients in a balanced equation are needed to calculate the equilibrium constant. You need to raise the concentrations to the power of how many mols are in the reaction.
- Fri Jan 11, 2019 11:56 pm
- Forum: Ideal Gases
- Topic: Q and K [ENDORSED]
- Replies: 35
- Views: 3193
Re: Q and K [ENDORSED]
The formulae themselves have no difference, but K is only used when the chemical reaction is at equilibrium. Using the equation with Q helps you determine whether the reaction goes forward or in reverse to reach equilibrium.
- Sun Nov 25, 2018 1:10 pm
- Forum: Octet Exceptions
- Topic: Octet vs formal charge
- Replies: 16
- Views: 3146
Re: Octet vs formal charge
Having the lowest formal charge is more important because the molecule will be more stable overall. There are some exceptions to the octet rule as well, so generally, following the rule of lowest formal charge would be the better bet.
- Sun Nov 25, 2018 12:53 pm
- Forum: Octet Exceptions
- Topic: The center atom
- Replies: 20
- Views: 3319
Re: The center atom
Cl is the least electronegative atom in the molecule, but since it has 7 valence electrons, it only has room left for one electron to complete the shell. It's more stable overall to have oxygen in the middle of the molecule.
- Sun Nov 25, 2018 12:40 pm
- Forum: Octet Exceptions
- Topic: Exceptions
- Replies: 3
- Views: 592
Re: Exceptions
The Octet Rule guideline only applies to period 2 elements because they must completely fill the second shell to achieve a stable state. The following elements on increasing period have the option to fill an additional d-orbital, so they are not confined to the Octet Rule.
- Fri Nov 02, 2018 8:43 pm
- Forum: Photoelectric Effect
- Topic: Chem Test 2, #5 b
- Replies: 4
- Views: 639
Re: Chem Test 2, #5 b
For that one, you would have to say no, because depending on the work function of the Hg atom, only certain wavelengths will be emitted when an e- reaches a certain energy level. In other words, atoms have discrete energy values, and if the wavelength emitted is not that value, then the atoms will n...
- Fri Nov 02, 2018 8:41 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Molar Mass
- Replies: 8
- Views: 1322
Re: Molar Mass
Each element on the periodic table has their molar mass listed below the atomic symbol. The units are in g/mol!
- Fri Nov 02, 2018 8:39 pm
- Forum: SI Units, Unit Conversions
- Topic: Molar Mass to Kg
- Replies: 6
- Views: 17727
Re: Molar Mass to Kg
You would need to divide by Avogadro's number to get the weight in grams and then multiply by 10^3 to convert to kg. But I'm assuming that if you're converting the mass, the mass of the element is given?
- Wed Oct 24, 2018 6:58 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 7
- Views: 708
Re: Rydberg Equation
Would we use the E= -hr/n^2 along with E=hv to solve for nu and the subsequently c=lambda*nu to find wavelength?
- Wed Oct 24, 2018 6:54 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Wave functions
- Replies: 4
- Views: 449
Re: Wave functions
I think it's the other way around. Through the wave functions and Schrodinger's equations, you are able to get the quantum numbers for each electron in an atom (n, l, m(l)). However, Lavelle has said we won't be doing Schrodinger's for this test.
- Wed Oct 24, 2018 6:52 pm
- Forum: Properties of Light
- Topic: kg or g [ENDORSED]
- Replies: 11
- Views: 1696
Re: kg or g [ENDORSED]
I remember in class Lavelle said he wanted us to use kg since it is the SI unit for mass. That way, with all the equations the units will be able to cancel out.
- Sat Oct 20, 2018 4:51 pm
- Forum: Properties of Light
- Topic: 3 Posts on Chemistry Community [ENDORSED]
- Replies: 5
- Views: 471
Re: 3 Posts on Chemistry Community [ENDORSED]
I've only ever heard that we need to post three questions or comments by Sunday. I think the new week starts each Monday, since Sunday is the last day to post. You can create your own post by going into Chem 14A > [A Topic, e.g. "The Quantum World"]> and then hitting "New Topic" ...
- Sat Oct 20, 2018 4:28 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Symmetry in electron density distribution
- Replies: 3
- Views: 1681
Re: Symmetry in electron density distribution
In symmetrical electron density distribution, the likelihood of finding an electron in any given point within the orbital is relatively the same. In asymmetrical electron density distribution, there are certain areas where it is less likely to find an electron. For example, in the nodal plane, the l...
- Sat Oct 20, 2018 4:25 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Superscript
- Replies: 3
- Views: 301
Re: Superscript
In electron configuration, a superscript indicates the number of electrons occupying each orbital. So in your example, it means two electrons are in the 2S orbital.
- Sun Oct 14, 2018 11:48 pm
- Forum: Properties of Light
- Topic: Units for Wavelength
- Replies: 7
- Views: 705
Re: Units for Wavelength
I would ask your TA which they would prefer, but technically speaking, as long as you notate it correctly as nm, or x10^-9 m it should be fine, since they both mean the same thing.
- Sun Oct 14, 2018 11:43 pm
- Forum: Einstein Equation
- Topic: Symbol for frequency
- Replies: 12
- Views: 2297
Re: Symbol for frequency
It's best to just stick with what the textbook and Dr. Lavelle has been using in class, "v" (nu).
- Sun Oct 14, 2018 11:42 pm
- Forum: Photoelectric Effect
- Topic: Threshold energy [ENDORSED]
- Replies: 17
- Views: 2204
Re: Threshold energy [ENDORSED]
Each atom has a minimum amount of energy needed for an electron to be released. That is the threshold amount of energy needed. Any energy more than that is excess and is given to the electron that is released. It is not used in calculating the energy of a photon.
- Sat Oct 06, 2018 9:39 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3667224
Re: Post All Chemistry Jokes Here
A chemist and his friend go into a bar. The chemist says "I'll have some h2o, please." His friend says, "I'll have some h2o, too." His friend is now dead.
- Sat Oct 06, 2018 9:36 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical formula set up
- Replies: 9
- Views: 672
Re: Empirical formula set up
If you use 100g, you don't have to worry about having to calculate percentages and using complicated numbers, it speeds up the process without doing too many extra steps!
- Sat Oct 06, 2018 9:33 pm
- Forum: SI Units, Unit Conversions
- Topic: Modules?
- Replies: 8
- Views: 727
Re: Modules?
I thought I heard someone say they were supposed to be done by week 2? But then again, it also says the modules are done anonymously?