Search found 62 matches
- Sun Mar 17, 2019 7:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Grade Release Date?
- Replies: 7
- Views: 962
Re: Final Grade Release Date?
Also when can we pick up the exams next quarter?
- Sat Mar 16, 2019 10:35 am
- Forum: Student Social/Study Group
- Topic: Lyndon's Review Session
- Replies: 8
- Views: 1512
Re: Lyndon's Review Session
Has the worksheet been posted?
- Sat Mar 16, 2019 10:10 am
- Forum: Student Social/Study Group
- Topic: class pictures
- Replies: 15
- Views: 3973
Re: class pictures
one more
- Sat Mar 16, 2019 10:10 am
- Forum: Student Social/Study Group
- Topic: class pictures
- Replies: 15
- Views: 3973
Re: class pictures
Here are some more pictures:)
- Fri Mar 15, 2019 9:04 am
- Forum: General Rate Laws
- Topic: Elementary steps
- Replies: 1
- Views: 321
Re: Elementary steps
Adding on to their question ^ does it, in that case, mean the coefficient in the rate law is not 1/x but just 1?
- Fri Mar 15, 2019 9:02 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Rate constants at equilibrium
- Replies: 5
- Views: 596
Re: Rate constants at equilibrium
No it depends on your Big K = to small k 1 over small k -1.
- Fri Mar 15, 2019 9:01 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Specific Heat Capacity and Heat Capacity
- Replies: 2
- Views: 571
Re: Specific Heat Capacity and Heat Capacity
Remember Specific Heat Capacity is m*delta T*C and it is, in fact, an intensive property because no matter how much of something there is, its ability to absorb heat at the particular temperature is the same.
- Wed Feb 27, 2019 9:59 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Problem 14.15c 6th edition
- Replies: 1
- Views: 249
Re: Problem 14.15c 6th edition
I'm really confused by this one too because of the KOH and Ni in the cell diagram :/
- Wed Feb 27, 2019 9:45 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams in 14.15 and 14.17 6th Ed
- Replies: 4
- Views: 429
Re: Cell Diagrams in 14.15 and 14.17 6th Ed
Solutions of the same phase are separated by a comma and arranged in the oxidized, reduced order
- Wed Feb 27, 2019 9:23 am
- Forum: Balancing Redox Reactions
- Topic: 14.15a
- Replies: 3
- Views: 1622
Re: 14.15a
I am confused on this too but essentially I think it is because the oxidation number for Bromine do not change.
- Sun Feb 24, 2019 2:56 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 2
- Replies: 9
- Views: 1058
Re: Test 2
In addition to what some classmates said, we should also know enthalpy and entropy because they are part of a Gibbs equation.
- Sun Feb 24, 2019 2:27 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneity
- Replies: 8
- Views: 788
Re: Spontaneity
If Gibbs is at 0 it is at equilibrium, if it is negative then it is exergonic meaning it is also spontaneous. If it is positive it is endergonic which means it is non-spontaneous. The lower the delta G is the more stable it is.
- Sun Feb 24, 2019 2:25 pm
- Forum: Balancing Redox Reactions
- Topic: difference between oxidation and reduction
- Replies: 8
- Views: 915
Re: difference between oxidation and reduction
OIL RIGS helps me remember that when Oxidation happens it Loses Electrons. When Reduction happens it Gains electrons. It is oxidation because it lost two electrons therefore increasing it's positive charge.
- Sun Feb 24, 2019 2:23 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Material
- Replies: 13
- Views: 1302
Re: Test 2 Material
Gibbs free energy for sure and some electrochemistry is possible. I'm not sure how much:/
- Sun Feb 24, 2019 2:20 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs energy
- Replies: 2
- Views: 293
Re: Gibbs energy
Delta G^0 is for standard conditions such as standard temperature (25 degrees celcius/298K). Delta G is for nonstandard conditions and depends on those, this means temperature, for instance, is not standard.
- Fri Feb 22, 2019 9:30 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Equations of delta G
- Replies: 4
- Views: 510
Re: Equations of delta G
It is usually based on your givens and if you have enthalpy then most likely the first one will be used. It helps to check off what you have and see what you can plug in.
- Fri Feb 22, 2019 9:27 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G=0 at equilibrium
- Replies: 4
- Views: 2490
Re: Delta G=0 at equilibrium
When Gibbs free energy is equal to 0 that means that the reaction is at equilibrium meaning that no more work can be done.
- Fri Feb 22, 2019 9:25 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Isochoric
- Replies: 3
- Views: 668
Re: Isochoric
That is also another way of saying it is isometric which means volume is constant
- Fri Feb 22, 2019 9:24 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free energy
- Replies: 5
- Views: 575
Re: Gibbs Free energy
Standard temperature is 25 degrees celcius, however for Gibbs free energy we always use Kelvin so it is 273+25 which is 298 K
- Thu Feb 21, 2019 12:11 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs concept
- Replies: 7
- Views: 710
Re: Gibbs concept
Gibbs is the amount of useable free energy. So this is the total change in the energy minus the temperature times the total change in disorder of the system.
- Thu Feb 21, 2019 12:09 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Delta G a state function?
- Replies: 23
- Views: 2755
Re: Delta G a state function?
Yes and I remember because Lyndon said once he was "Feeling a little Pressured and Dense. He wished he could just watch TV and get HUGS.
(PV TV HUGS).
(PV TV HUGS).
- Thu Feb 21, 2019 12:07 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Systems
- Replies: 6
- Views: 933
Re: Systems
Open you can think of it as if something can fall out of it, hence it can exchange heat and matter. Like a plant, it is exposed. Closed well nothing can fall out, but heat can still be exchanged. Isolated nothing is exchanged because it is isolated away from everything.
- Thu Feb 21, 2019 12:05 am
- Forum: Balancing Redox Reactions
- Topic: H+ vs H3O+
- Replies: 10
- Views: 957
Re: H+ vs H3O+
Some people say to use H+, and I'm not sure if it's the same as with acids and bases because during that time using either one was fine.
- Thu Feb 21, 2019 12:04 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: When does delta U equal zero?
- Replies: 17
- Views: 8224
Re: When does delta U equal zero?
When the reactions says it is isothermal that means that the temperature is constant (iso=same). If this is the case then there is no change in the internal energy therefore U is 0.
- Thu Feb 21, 2019 12:02 am
- Forum: Ideal Gases
- Topic: units
- Replies: 15
- Views: 1309
Re: units
Yes remember K does not have a unit because it is a ration and I believe those units cancel out.
- Thu Feb 21, 2019 12:01 am
- Forum: Balancing Redox Reactions
- Topic: Week 7 Homework
- Replies: 15
- Views: 1196
Re: Week 7 Homework
Most likely Gibbs and maybe some electrochemistry, but mostly Gibbs.
- Wed Feb 20, 2019 11:59 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: entropy
- Replies: 4
- Views: 604
Re: entropy
Enthalpy is the delta H and Entropy is the delta S. Basically Enthalpy is the total energy in the system and entropy is the measure of disorder. Also, note that the second law of thermodynamics shows that disorder is increasing.
- Tue Feb 12, 2019 12:01 am
- Forum: Student Social/Study Group
- Topic: Too cute
- Replies: 5
- Views: 1206
Re: Too cute
I'm new to uploading videos apparently, so hopefully, this video of the acapella performance uploaded below in the attachments...
- Mon Feb 11, 2019 6:23 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
- Replies: 49
- Views: 11477
Re: Lyndon's HOTDOG MIDTERM REVIEW SESSION!! FINALLY!
Thank you, I had such a hard time finding it haha!
- Thu Feb 07, 2019 3:01 pm
- Forum: Ideal Gases
- Topic: Lyndon's review session
- Replies: 7
- Views: 794
Re: Lyndon's review session
It's from 7-10 on Monday Franz 1178. I cannot find the worksheet either :(
- Tue Jan 22, 2019 10:14 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ice chart
- Replies: 7
- Views: 866
Re: ice chart
Typically the problems provide initial molarity or ask for you to calculate the molarity or initial values. I is for initial molarity, C is for change, and E is for equilibrium concentration
- Tue Jan 22, 2019 10:11 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Strong acids and bases
- Replies: 6
- Views: 562
Re: Strong acids and bases
I believe it is best to memorize some for strong acids and bases. I do not remember which ones, but I think the ones common in homework are good to know.
- Sat Dec 08, 2018 6:31 pm
- Forum: Naming
- Topic: Common Ligands
- Replies: 2
- Views: 300
Re: Common Ligands
I would know them, better safe than sorry. Maybe more the ones that we saw in the homework probs too.
- Sat Dec 08, 2018 6:26 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: HOCl vs HOI
- Replies: 9
- Views: 4121
Re: HOCl vs HOI
Electronegativity is the tendency of an atom to attract a bonding pair of electrons and Cl is more electronegative than I. The weaker the bond the more likely it will lose an H+. Also HOCL is more stable.
- Sat Dec 08, 2018 6:21 pm
- Forum: Biological Examples
- Topic: Chemotherapy Drugs
- Replies: 1
- Views: 475
Re: Chemotherapy Drugs
Cisplatin is one that comes to mind because it stops cell division
- Sat Dec 08, 2018 6:17 pm
- Forum: Lewis Acids & Bases
- Topic: Trends of Acids and Bases
- Replies: 2
- Views: 330
Re: Trends of Acids and Bases
Typically we compare A-H bonds with other bonds like that and the oxoacids (AO-H) bonds with others like it.
- Sat Dec 08, 2018 6:15 pm
- Forum: Hybridization
- Topic: Power
- Replies: 1
- Views: 401
Re: Power
Hi, if you are referring to the 2 after C then that is the level it is on and it is not a power. If it is the 2 after the P then that is a power. Yes you should write this when writing the sigma bonds.
- Sat Dec 08, 2018 6:12 pm
- Forum: Bronsted Acids & Bases
- Topic: H vs OH
- Replies: 3
- Views: 435
Re: H vs OH
The longer the A-H bond the easier it is to remove the H+. With AO-H bond the more electronegative the central atom the more acidic the molecule will become.
- Sat Dec 08, 2018 6:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: radical
- Replies: 5
- Views: 632
Re: radical
Radicals have at least one unpaired electron and they have an odd number of valence electrons. Note they're also very reactive
- Sun Dec 02, 2018 5:55 pm
- Forum: Coordinate Covalent Bonds
- Topic: Identifying Polydentates
- Replies: 4
- Views: 772
Re: Identifying Polydentates
I'm not sure if this is 100% for certain but I think there is a few we just sort of have to remember are polydentate, for instance, en, ethylenediamine or dien, diethylenetriamine. But I doubt he will give us some that we have not reviewed
- Sun Dec 02, 2018 5:48 pm
- Forum: Naming
- Topic: 6th Edition Ch 17.5 #31 b and d
- Replies: 1
- Views: 152
Re: 6th Edition Ch 17.5 #31 b and d
Okay so the 3/III, as I learned, is the oxidation number, so basically for b) if you calculate the oxidation number NH3 and OH2 are neutral meaning they are 0 and add that to cobalt which was "unknown" it will equal 3 because your oxidation number is 3. Essentially, I would write it like t...
- Sun Dec 02, 2018 5:35 pm
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: Transition Metals
- Replies: 5
- Views: 1772
Re: Transition Metals
Transition metals are capable of adopting ions with different charges because in mind they are in the d-block so they one or more unpaired electrons in one of their ions.
- Sun Dec 02, 2018 4:50 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Oxidation number
- Replies: 3
- Views: 453
Re: Oxidation number
I'll do an example so hopefully, it makes more sense. Take for instance, [Fe(CN)6]^(4-) --hexacyanoferrate (II) ion (note 6 is a subscript). Note that transition metals charge vary. I usually start by putting an X to represent "unknown" for my metal which is Fe. So, I have: X+(-1)6= -4. Th...
- Sun Dec 02, 2018 4:06 pm
- Forum: Naming
- Topic: Order of Ligands
- Replies: 2
- Views: 331
Re: Order of Ligands
I recall it was supposed to be in alphabetical order, so in that case your first one would be correct.
- Sun Dec 02, 2018 4:02 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelates: are the rings a part of the coordination sphere?
- Replies: 2
- Views: 268
Re: Chelates: are the rings a part of the coordination sphere?
I do believe so because the coordination sphere consists of the central ion or atom along with all the ligands.
- Sun Dec 02, 2018 3:54 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How to determine coordination number
- Replies: 3
- Views: 325
Re: How to determine coordination number
Coordination number I know as simply the number of bonds used to attach to all ligands.
- Sun Nov 25, 2018 6:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Electron Arrangement vs. Molecular Shape
- Replies: 2
- Views: 438
Re: Electron Arrangement vs. Molecular Shape
Hi, so I had had the same question, but I learned that electron arrangement basically means all the electron densities around the atom. In other words, all the stuff around it so that could be the other element(s) and any lone pair of electrons, (this is the steric number.) Once you have this, you l...
- Sun Nov 25, 2018 6:44 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sigma vs pi bonds
- Replies: 7
- Views: 728
Re: Sigma vs pi bonds
A sigma bond is the strongest type of covalent chemical bond. A pi bond contains p-p orbitals and it is a covalent bond formed by the side to side overlap of orbitals, which can be easily broken. Also, a single bond consists of a sigma bond, and let's say you have a double bond, this consists of a s...
- Sun Nov 25, 2018 6:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 3 material
- Replies: 6
- Views: 700
Re: Test 3 material
I have a feeling it will cover things we have been over since after the midterm and probably a bit from before, such as VSEPR models, knowing molecular shape and structure names, and polarity. There may be some stuff from this week that could potentially be there.
- Sun Nov 18, 2018 8:58 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Drawing structures
- Replies: 8
- Views: 772
Re: Drawing structures
I can't say I'm positive, but I don't think we will worry about that for VSPER in Chem 14 a. However, I think it is important for when you draw your Lewis structure though :)
- Fri Nov 16, 2018 4:40 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: tetrahedral vs trigonal planar
- Replies: 9
- Views: 1065
Re: tetrahedral vs trigonal planar
So what helps best is to draw the Lewis structure of the compound. So you have your central atom and typically the other surrounding atoms. If there are no lone pairs and it has 4 surrounding atoms it is tetrahedral (tetra=4). However, if it is trigonal planar (tri=3) then it only has 3 surrounding ...
- Fri Nov 16, 2018 4:34 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Planar vs Pyramidal
- Replies: 5
- Views: 534
Re: Planar vs Pyramidal
Yes, there is a difference. So trigonal pyramidal has a pyramid shape and if you can try to imagine it with a base in a triangular shape. (it may be helpful to look for a 3D image). Also, t's bond angles are slightly less than 109 degrees and this is because it has one lone pair of electrons that ca...
- Sat Nov 10, 2018 6:04 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs
- Replies: 4
- Views: 351
Re: Lone Pairs
I believe the shape/angle change has to do with electron repulsion. (This is important because it determines if something is polar or nonpolar.) I also read online that lone pairs occupy more space compared to bonding pairs of electrons, hence this results in greater repulsion between lone pairs of ...
- Sat Nov 10, 2018 5:57 pm
- Forum: Resonance Structures
- Topic: Bond Lengths
- Replies: 6
- Views: 896
Re: Bond Lengths
Can someone explain bond lengths, I understand the whole single bond is weaker...but what are the most important things for us to know about them?
- Sat Nov 10, 2018 5:54 pm
- Forum: Ionic & Covalent Bonds
- Topic: Relation between strong acid and weak bond
- Replies: 3
- Views: 444
Re: Relation between strong acid and weak bond
I believe you already know, but keep in mind a single bond the weakest bond, and a triple bond is strongest. I think HI is a stronger acid because the bond is weak which means it can be broken easily. Also, acids want to take in more electrons and considering the single bond is a weaker bond it will...
- Thu Nov 01, 2018 8:29 pm
- Forum: Sigma & Pi Bonds
- Topic: Easy way of remembering the difference
- Replies: 6
- Views: 696
Re: Easy way of remembering the difference
Between bonds, do you mean ionic and covalent? If you do, I usually look at the elements. If it has a metal in it, it is ionic because ionic bonds typically transfer one electron from a metal to a nonmetal. And if it has a positive charge it is a cation. This means it lost an electron hence making i...
- Thu Nov 01, 2018 8:23 pm
- Forum: Resonance Structures
- Topic: Most Stable Configuration
- Replies: 11
- Views: 1166
Re: Most Stable Configuration
The most stable configuration is one in which its formal charge would be 0. This can be determined with the formula V-(L+S/2), where v is the valence electrons, L is the lone pair of electrons and S is the shared electrons over 2.
- Thu Nov 01, 2018 8:20 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 8
- Views: 739
Re: Formal Charge
V is for valence electrons, L is for lone pair of electrons, and then S is for shared electrons. Don't forget also the formula V-(L+S/2)
- Wed Oct 24, 2018 12:36 am
- Forum: DeBroglie Equation
- Topic: equation definition
- Replies: 5
- Views: 906
Re: equation definition
I believe the difference is that de Broglie's equation includes matter. Matter according to the de Broglie has wave-like behavior and this equation, therefore, is meant to include how to calculate the wavelength of an object of mass. The wave equation we worked with initally (c=wavelength*v) did not...
- Wed Oct 17, 2018 11:32 pm
- Forum: Einstein Equation
- Topic: Numbers to memorize [ENDORSED]
- Replies: 37
- Views: 4010
Re: Numbers to memorize [ENDORSED]
I think it is possible they may provide numbers we do not know for the test, however once we do practice problems I think you will memorize them. Currently the speed of light and plank's constant are ones we will gradually remember.
- Wed Oct 17, 2018 11:26 pm
- Forum: Photoelectric Effect
- Topic: Definition for photoelectric effect
- Replies: 4
- Views: 459
Re: Definition for photoelectric effect
The definition that makes the most sense to me is, the ejection of electrons from the surface of a metal when exposed to UV radiation of frequency above the threshold frequency of the metal.
- Wed Oct 17, 2018 11:22 pm
- Forum: Properties of Light
- Topic: Sig Figs in Problem 1.13 (6th Edition)
- Replies: 5
- Views: 441
Re: Sig Figs in Problem 1.13 (6th Edition)
I don't believe sig figs matter too much in this case, but I usually go with three in those cases. Verify with the TA