Search found 108 matches
- Fri Mar 13, 2020 6:12 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Slow Step Mechanism
- Replies: 7
- Views: 478
Re: Slow Step Mechanism
It is reaction dependent and there is no general assumption that can be made unless give the problem's specifics
- Fri Mar 13, 2020 6:08 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 11
- Views: 716
Re: Final
Lavelle's emails provide all the information we need to know about the final.
- Fri Mar 13, 2020 6:06 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: calorimetry
- Replies: 9
- Views: 615
Re: calorimetry
Regular calorimeters assume constant pressure while bomb calorimeters assume constant volume. They are both isolated systems
- Fri Mar 13, 2020 5:40 pm
- Forum: Administrative Questions and Class Announcements
- Topic: "Open Book" Final?
- Replies: 30
- Views: 1976
Re: "Open Book" Final?
He said he'd update us tomorrow so I feel like we shouldn't worry or stress about it right now and instead just focus on studying and it'll work out.
- Fri Mar 13, 2020 5:37 pm
- Forum: Student Social/Study Group
- Topic: Tips for Staying Focused
- Replies: 64
- Views: 3588
Re: Tips for Staying Focused
People can stay focused in different ways. I like to drink coffee or tea while i study because it keeps me awake and alert
- Thu Mar 12, 2020 7:48 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: final
- Replies: 3
- Views: 335
Re: final
I think we can assume that the final will include about equal amounts of most outlines
- Wed Mar 11, 2020 1:08 am
- Forum: Student Social/Study Group
- Topic: Final Exam
- Replies: 22
- Views: 1533
Re: Final Exam
The final will be take-home and straight forward according to the email sent a few hours ago.
- Sun Mar 08, 2020 11:39 pm
- Forum: Student Social/Study Group
- Topic: Midterm and Final Question
- Replies: 18
- Views: 1018
Re: Midterm and Final Question
The study guide would be all of Lavelle’s outlines from the beginning of the quarter
- Sun Mar 08, 2020 11:38 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 100 or 50 posts?
- Replies: 8
- Views: 579
Re: 100 or 50 posts?
You should have 100 posts
- Sun Mar 08, 2020 11:37 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Notation Layout
- Replies: 7
- Views: 403
Re: Cell Notation Layout
Convention states that the anode (oxidation) should be on the left
- Sun Mar 08, 2020 11:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 Grades
- Replies: 22
- Views: 1166
Re: Test 2 Grades
We will probably get them back in time before the final to look over it
- Sun Mar 08, 2020 11:35 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Midterm
- Replies: 2
- Views: 279
Re: Midterm
I remember the question. For that, you needed to consider enthalpy change by relating equations
- Fri Feb 28, 2020 10:34 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2
- Replies: 10
- Views: 696
Re: Test 2
Lavelle mentioned in class that test 2 will cover outline 4 (that wasn't on the midterm) and outline 5. It is important to understand that none of the concepts can be taken in isolation and an understanding of previous concepts and outlines is necessary to do your best on test 2.
- Fri Feb 28, 2020 10:31 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Anode vs Cathode
- Replies: 15
- Views: 840
Re: Anode vs Cathode
Fundamentally, oxidation happens at the anode and reduction happens at the cathode. In terms of writing it out, you typically include the anode on the left and the cathode on the right.
- Fri Feb 28, 2020 8:52 pm
- Forum: Balancing Redox Reactions
- Topic: How to tell if its being reduced or oxidized
- Replies: 15
- Views: 1954
Re: How to tell if its being reduced or oxidized
You have to differentiate between the ions you are looking at. One of the elements gains electrons while the other loses. the mnemonic to help you remember the definitions of oxidation and reduction if that was your confusion is OIL RIG: Oxidation Is Losing; Reduction Is Gaining.
- Fri Feb 28, 2020 8:45 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Porous Disk and Salt Bridge
- Replies: 13
- Views: 1173
Re: Porous Disk and Salt Bridge
I don't believe there is a difference in efficiency. They serve the same purpose in balancing charges and the distribution of ions.
- Fri Feb 28, 2020 9:21 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 4
- Views: 889
Salt Bridge
Hi everyone,
My question refers to salt bridges and what they provide to each part of the diagram. I was confused on how they play a role in balancing charges? Do they provide electrons to one side or ions? Also, why don't they dissociate completely dissociate in the solutions they're in?
My question refers to salt bridges and what they provide to each part of the diagram. I was confused on how they play a role in balancing charges? Do they provide electrons to one side or ions? Also, why don't they dissociate completely dissociate in the solutions they're in?
- Sun Feb 23, 2020 4:21 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: relevance of salt bridge
- Replies: 9
- Views: 566
Re: relevance of salt bridge
A salt bridge essentially allows the "circuit" to be complete. It allows for a constant flow of charge without an immediate stop as a result of charge build-up. It essentially balances charge in ot=rder to keep the system going.
- Sun Feb 23, 2020 4:19 pm
- Forum: Student Social/Study Group
- Topic: Curve?
- Replies: 50
- Views: 6046
Re: Curve?
There is no curve in the class, but points and grade correlation are not determined until after the final exam has been posted. Your scores on the tests are not indicative of what your final grade will come out to be as Dr. Lavelle might adjust it slightly at the end of the quarter depending on what...
- Sun Feb 23, 2020 4:13 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 Material
- Replies: 16
- Views: 1013
Re: Test 2 Material
The material covered in test 2 will not include information from the coming weeks. He postponed it in order to give us more time to study for it.
- Sun Feb 23, 2020 4:11 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneous
- Replies: 23
- Views: 1169
Re: Spontaneous
In order for a reaction to be considered spontaneous, the value of delta G must be a negative number. delta g = delta H - TDELTAS. If delta g is 0, the reaction is at equilibrium.
- Sun Feb 23, 2020 4:09 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 9
- Views: 630
Re: Salt Bridge
I believe the best way to understand the concept of a salt bridge is to liken it to a closed circuit. In order for a circuit to be complete, there must be a closed-loop in order for charges of positives and negatives to get balanced and have somewhere to go. The salt bridge essentially completes the...
- Sun Feb 16, 2020 9:02 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: When to use the different equations
- Replies: 5
- Views: 400
When to use the different equations
Hi all,
So I'm having trouble figuring out when to use delta G = -RTlnk vs. the other equations for delta G. Is there a reason you would pick one equation over another? and what do you do differently when it is determined at constant pressure vs. volume
So I'm having trouble figuring out when to use delta G = -RTlnk vs. the other equations for delta G. Is there a reason you would pick one equation over another? and what do you do differently when it is determined at constant pressure vs. volume
- Sun Feb 16, 2020 8:56 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Midterm Curve
- Replies: 45
- Views: 2162
Re: Midterm Curve
On his syllabus it says that he does not curve but that grades will be determined at the end of the quarter
- Wed Feb 12, 2020 8:13 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Adiabatic
- Replies: 2
- Views: 180
Re: Adiabatic
An adiabatic system means that the system is isolated and therefore delta U = w + 0(q)
- Wed Feb 12, 2020 8:11 am
- Forum: Calculating Work of Expansion
- Topic: Midterm equation sheet
- Replies: 16
- Views: 689
Re: Midterm equation sheet
Yes, however, it is helpful to know the equations before hand because the units, definitions, and terms are not provided
- Wed Feb 12, 2020 8:08 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Boltzmann Formula
- Replies: 3
- Views: 162
Re: Boltzmann Formula
Yes, it is one of the topics Lavelle discussed in lecture and it is included in outline 4
- Tue Feb 04, 2020 12:55 am
- Forum: Administrative Questions and Class Announcements
- Topic: Video Outlines
- Replies: 3
- Views: 255
Video Outlines
Are there video outlines for any of the recent topics?
- Tue Feb 04, 2020 12:54 am
- Forum: Administrative Questions and Class Announcements
- Topic: Course Reader
- Replies: 1
- Views: 103
Course Reader
How do we access the course reader?
- Tue Feb 04, 2020 12:54 am
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm
- Replies: 6
- Views: 311
Midterm
Which equations should we memorize/ will need to know off the top of our heads for the midterm?
- Tue Feb 04, 2020 12:51 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: defintion
- Replies: 6
- Views: 358
Re: defintion
Internal energy is just the energy found within a system without any interference from the world beyond. It is the concept of energy only being from the kinetic and potential energy already found within a system
- Tue Feb 04, 2020 12:49 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Enthalpy
- Replies: 2
- Views: 107
Enthalpy
Is enthalpy just the change in energy? what does it mean to have a positive or negative change in enthalpy? When would such changes occur?
- Tue Feb 04, 2020 12:47 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Differences between systems
- Replies: 3
- Views: 236
Differences between systems
I am still a little bit confused on the difference between a closed and isolated system. Could someone provide the definitions and explain the differences?
- Sun Feb 02, 2020 1:53 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 5 Homework
- Replies: 7
- Views: 248
Re: Week 5 Homework
Since the midterm is soon, you can pick any of the topics we've already gone over. It might be most helpful to review topics from the most recent lectures
- Sun Feb 02, 2020 1:47 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Elements
- Replies: 8
- Views: 140
Re: Elements
Diatomic molecules such as H2, O2, N2, F2, I2, CL2, and Br2 all have an enthalpy of formation of 0 because it is their naturally occuring state. There is no enthalpy of formation for the way something is already formed. However, if you were to change the molecule, then there would be an enthalpy of ...
- Sun Feb 02, 2020 1:43 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Entropy units
- Replies: 4
- Views: 207
Re: Entropy units
As long as all the calculations are correct and the units match up then you can use either one. However, changing units constantly may result in accidental mix ups, so you should be fine as long as you stay consistent
- Sun Feb 02, 2020 1:42 pm
- Forum: Phase Changes & Related Calculations
- Topic: Calorimeter
- Replies: 8
- Views: 553
Re: Calorimeter
A bomb calorimeter is a more robust and accurate calorimeter. It can withstand more pressure, so it is typically more often used
- Sun Feb 02, 2020 1:40 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated System
- Replies: 4
- Views: 138
Re: Isolated System
In an isolated system, energy is transferred, so q=0, q=0, and delta u also equals 0
- Sun Jan 26, 2020 7:55 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: solvent
- Replies: 10
- Views: 388
Re: solvent
A solvent is the substance in excess that other reactants are being dissolved in. E.g. Water is a solvent. Salt is a solute
- Sun Jan 26, 2020 7:53 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: exo thermic
- Replies: 11
- Views: 349
Re: exo thermic
In an exothermic reaction, heat is found on the right side of the equation, therefore, by adding heat, you would shift the reaction away from where there is an excess so it would shift to the left (reactants).
- Sun Jan 26, 2020 7:51 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Fall Quarter Final?
- Replies: 12
- Views: 780
Re: Fall Quarter Final?
I would email the TA from last quarter's discussion section asking when a good time would be to come and pick up the tests
- Sun Jan 26, 2020 7:50 pm
- Forum: Phase Changes & Related Calculations
- Topic: Heat vs temperature
- Replies: 6
- Views: 335
Re: Heat vs temperature
Temperature and heat are different in that for a sample of boiling water, the temperature would remain the same until it undergoes a phase change while heat would be continuously added
- Sun Jan 26, 2020 7:48 pm
- Forum: Phase Changes & Related Calculations
- Topic: Why does steam cause burns?
- Replies: 29
- Views: 1127
Re: Why does steam cause burns?
Steam causes burns due to the high amount of heat transferred from the steam to skin. It has a large Q and H value.
- Sun Jan 26, 2020 7:47 pm
- Forum: Phase Changes & Related Calculations
- Topic: Delta H
- Replies: 3
- Views: 160
Re: Delta H
All the necessary information regarding what is needed for a problem would be provided. It is best to know how to calculate Delta H in case it is one of the values unaccounted for, but otherwise, it would be provided. We are not expected to memorize any values.
- Fri Jan 17, 2020 9:27 am
- Forum: Administrative Questions and Class Announcements
- Topic: Grading
- Replies: 8
- Views: 569
Re: Grading
Ask your TA because it varies depending on the TA's preference. Just to be sure, I recommend posting at least 5 times a week.
- Fri Jan 17, 2020 9:18 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Stress
- Replies: 4
- Views: 102
Re: Stress
A stress applied to the system is any altercation made that shifts the reaction rates. Stressors include temperature, pressure, the removal or addition of a product or reaction, and the addition of a different reactive sbstance
- Fri Jan 17, 2020 9:15 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Exothermic
- Replies: 5
- Views: 246
Re: Exothermic
Energy is released when bonds are formed because the atoms go to a lower energy state that is more stable.
- Fri Jan 17, 2020 9:14 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Tips for Test
- Replies: 23
- Views: 1099
Re: Tips for Test
I would read the textbook first as it is the most in depth review of the lecture material you could get. I would then review the lecture notes then do the homework, going over how to approach the homework problems if you get them wrong.
- Fri Jan 17, 2020 9:12 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Kw
- Replies: 16
- Views: 382
Re: Kw
Kw = 1.0 *10^-14 is the equilibrium constant for water, which is also defined as Kw = Ka * Kb. The two definitions you gave are interchangeable for the most part
- Sun Jan 12, 2020 3:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 1 date
- Replies: 4
- Views: 250
Re: Test 1 date
Dr. Lavelle has the test and exam schedule on the class webpage. For test 1, it will be starting on Tuesday the 21st in your discussion section
- Sun Jan 12, 2020 3:52 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Test 1
- Replies: 6
- Views: 217
Re: Test 1
Test 1 is starting on Jan 21st in your discussion section. Dr. Lavelle has the tests/exam schedule up on the class page
- Sun Jan 12, 2020 3:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: General HW question
- Replies: 9
- Views: 364
Re: General HW question
The TAs said that it is graded based on a demonstrated effort of answering 5 questions. This is due to the fact that we have access to the solution manual so grading on how many are correct wouldn't be as effective and would dissuade students from actually trying
- Sun Jan 12, 2020 3:48 pm
- Forum: Ideal Gases
- Topic: Topics on Test 1
- Replies: 37
- Views: 1302
Re: Topics on Test 1
Outline 1 and everything mentioned in the assigned readings/homework assignments/lectures. I believe that test 1 will hold us accountable for everything up until the lecture right before the test
- Sun Jan 12, 2020 3:46 pm
- Forum: Ideal Gases
- Topic: Test 1
- Replies: 7
- Views: 356
Re: Test 1
The best way to determine that is through lectures and the readings on the syllabus. I believe that in the syllabus Dr. Lavelle mentioned that 1 question on every test will be from the homework problems, so those are also a great way of studying.
- Sun Jan 12, 2020 3:44 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14A Final Pickup
- Replies: 5
- Views: 200
Re: 14A Final Pickup
You'll be able to start picking them up next week from Young Hall. Room 3034 I believe. I'm not sure when the last day to pick them up is but Dr. Lavelle sent out the info in an email a few weeks after the final.
- Sun Jan 12, 2020 3:42 pm
- Forum: Ideal Gases
- Topic: Units of Pressure
- Replies: 8
- Views: 251
Re: Units of Pressure
It is helpful to understand the general proportionalities between the different units of pressure because although we will be getting a conversion sheet, sometimes you may have used a wrong conversion that you could easily identify based on what you would approximate it to be.
- Wed Dec 04, 2019 6:05 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Hydrogen bonding
- Replies: 1
- Views: 236
Hydrogen bonding
What is a hydrogen bond site? and for hydrogen bonding to occur do both compounds need to contain a hydrogen bonded to F O or N or can you have one compound that involves a bond between H and F O or N and the other compound to just be an F O or N not bonded to a H. For example is the bond between H3...
- Wed Dec 04, 2019 6:00 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: hybridizing coordination compounds
- Replies: 1
- Views: 159
hybridizing coordination compounds
Do you hybridize coordination compounds and the ligands they contain? and if so how?
- Wed Dec 04, 2019 11:15 am
- Forum: Naming
- Topic: Determining Type of Ligand
- Replies: 2
- Views: 76
Re: Determining Type of Ligand
There are also certain ones you should commit to memory. Those being:
EDTA (can be hexadente)
Ethylenediamine (can be bidente)
diethylenetriamine(can be tridente)
oxalato (can be bidente)
EDTA (can be hexadente)
Ethylenediamine (can be bidente)
diethylenetriamine(can be tridente)
oxalato (can be bidente)
- Wed Dec 04, 2019 10:28 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Drawing structures on the final
- Replies: 3
- Views: 188
Drawing structures on the final
Are we expected to know how to draw different coordination compound structures? do we need to know how to draw chelating coordination compounds?
- Wed Dec 04, 2019 10:26 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Isomers on the final
- Replies: 1
- Views: 129
Isomers on the final
to what extent do we have to understand the topic of isomers and the idea of cis vs trans? do we have to be able to identify different types of isomers on the final?
- Wed Dec 04, 2019 9:12 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Do we need to know the formation constant?
- Replies: 1
- Views: 153
Re: Do we need to know the formation constant?
It would be helpful to understand the general concept. The equilibrium constant is set up mainly to show what the reaction favors and what the complex's ligands are most likely to be. When analyzing reactions involving the equilibrium constant, it is generally a formation of the products over the re...
- Sat Nov 30, 2019 10:24 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2 Grades
- Replies: 10
- Views: 645
Re: Test 2 Grades
Most likely, I would assume, they would be up by Wednesday's lecture in order to give us adequate time to go over them before the final
- Sat Nov 30, 2019 10:23 pm
- Forum: Hybridization
- Topic: What to consider for hybridization?
- Replies: 3
- Views: 243
Re: What to consider for hybridization?
consider lewis structure, orbitals, and electron pairs which also get hybridized
- Sat Nov 30, 2019 10:21 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Calculating pOH
- Replies: 2
- Views: 107
Re: Calculating pOH
It is material that most likely will be covered in the next lecture but if you are preparing early, it is always better to over prepare than under prepare
- Sat Nov 30, 2019 10:19 pm
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: What to know for the final
- Replies: 8
- Views: 444
Re: What to know for the final
I would assume it would not be on the final and that only lecture content and readings will be covered
- Sat Nov 30, 2019 10:16 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Content
- Replies: 14
- Views: 764
Re: Final Exam Content
The final will be cumulative of everything since the beginning of the quarter
- Sat Nov 30, 2019 10:14 pm
- Forum: Student Social/Study Group
- Topic: Final Preparation
- Replies: 2
- Views: 190
Re: Final Preparation
I feel like it would be best to prepare with the mindset that all topics would be covered equally
- Sun Nov 24, 2019 1:03 pm
- Forum: Hybridization
- Topic: Strength of sigma and pi bonds
- Replies: 8
- Views: 655
Re: Strength of sigma and pi bonds
sigma bonds are harder to break than pi bonds because the former are a result of end-to-end bonding while the latter consist of side-to-side bonds
- Wed Nov 20, 2019 7:52 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: IMF strength
- Replies: 4
- Views: 253
IMF strength
Are hydrogen bonds stronger or Ion-dipole?
- Wed Nov 20, 2019 4:04 pm
- Forum: Electronegativity
- Topic: electronegativity of hydrogen
- Replies: 3
- Views: 313
Re: electronegativity of hydrogen
Ionic character depends on the difference in electronegativity values. The greater the difference, the more ionic
- Wed Nov 20, 2019 4:02 pm
- Forum: General Science Questions
- Topic: Test 2
- Replies: 7
- Views: 543
Re: Test 2
It all has to be memorized, but i found that ionce you understand 1 row, the rest become easier
- Wed Nov 20, 2019 2:06 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Boiling/melting points
- Replies: 5
- Views: 265
Re: Boiling/melting points
The boiling point and melting point depend on the strength of the bonds. Typically stronger bonds mean a higher boiling/melting point
- Fri Nov 15, 2019 11:07 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Formula Notation
- Replies: 4
- Views: 146
Re: VSEPR Formula Notation
The letters represent: the central atom, bonds, and lone pairs
- A = Central atom
- X = Bonds
- E = Lone pairs
- A = Central atom
- X = Bonds
- E = Lone pairs
- Fri Nov 15, 2019 11:05 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar vs Nonpolar molecules
- Replies: 4
- Views: 176
Re: Polar vs Nonpolar molecules
The best way to determine whether or not a molecule is non-polar or polar is by analyzing the vectors of electron distribution and pulls depending on electronegativity
- Fri Nov 15, 2019 11:03 am
- Forum: Bond Lengths & Energies
- Topic: Bond lengths
- Replies: 8
- Views: 370
Re: Bond lengths
Because each element has different bond lengths depending on what it is being bonded with, we would probably be given the bond lengths in a question
- Fri Nov 15, 2019 11:00 am
- Forum: Sigma & Pi Bonds
- Topic: Hybridization
- Replies: 2
- Views: 186
Hybridization
We talk about hybridization a lot, but what does it actually mean for certain bonds to be hybridized? and do we hybridize all molecules?
- Fri Nov 15, 2019 10:58 am
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Viscosity/Surface Tension
- Replies: 7
- Views: 1692
Re: Viscosity/Surface Tension
The result of higher strength intermolecular forces, resulting from the hydrogen bonds between the water molecules, it is harder to break apart those bonds, which causes surface tensions
- Sun Nov 10, 2019 8:48 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Polarizability
- Replies: 3
- Views: 106
Re: Polarizability
For anions, polarizability increases the more electrons it has. For cations, it depends on how small and how charged the ions are
- Sun Nov 10, 2019 8:46 pm
- Forum: Lewis Structures
- Topic: Electronegative
- Replies: 14
- Views: 803
Re: Electronegative
Yes, electronegativity describes the pull of electrons. It increases up and to the right of the periodic table
- Wed Nov 06, 2019 12:39 pm
- Forum: Properties of Light
- Topic: De Broglie for Photon?
- Replies: 3
- Views: 243
Re: De Broglie for Photon?
You don't know the mass of a photon so debroigle's equation would not be applicable
- Wed Nov 06, 2019 12:37 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: orbitals vs. subshells
- Replies: 4
- Views: 525
Re: orbitals vs. subshells
When thinking about what defines an orbital or subshell with respect to quantum numbers, Ml would refer to orbitals while L refers to the s, p, d. f,.. subshells.
- Wed Oct 30, 2019 12:09 am
- Forum: Ionic & Covalent Bonds
- Topic: grading
- Replies: 5
- Views: 227
Re: grading
It is either on My UCLA under "discussions" or the actual lecture
- Wed Oct 30, 2019 12:07 am
- Forum: Octet Exceptions
- Topic: aufbau principle
- Replies: 8
- Views: 334
Re: aufbau principle
There's less energy in the 3rd energy level than the 4th, because of the reality that it takes more energy to maintain stability in the 4th energy level
- Wed Oct 30, 2019 12:06 am
- Forum: Bond Lengths & Energies
- Topic: Bond lengths
- Replies: 15
- Views: 991
Re: Bond lengths
There's no formula but there are very specific lengths for certain bonds that I doubt will be expected knowledge to know on the test
- Wed Oct 30, 2019 12:04 am
- Forum: Ionic & Covalent Bonds
- Topic: Valence e-
- Replies: 3
- Views: 190
Re: Valence e-
It's good practice to understand the whole concept of valence shells, but also understand that the bohr model is not always representative of reality
- Tue Oct 29, 2019 11:57 pm
- Forum: Ionic & Covalent Bonds
- Topic: Octet Rule
- Replies: 8
- Views: 303
Re: Octet Rule
Elements in row 3 and beyond is usually the rule of thumb because they have empty orbitals
- Wed Oct 23, 2019 12:46 pm
- Forum: General Science Questions
- Topic: Study Tips
- Replies: 13
- Views: 872
Re: Study Tips
The homework problems are helpful once you already understand the information so I recommend going to review sessions/ watching helpful chemistry videos then doing the homework problems slowly and making sure you understand why you got a certain answer
- Wed Oct 23, 2019 12:42 pm
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity Trends
- Replies: 5
- Views: 596
Re: Electron Affinity Trends
When thinking about electron affinity think about how close the electrons are to the nucleus (where the protons are). Electron affinity increases the closer the electrons are to the nucleus, so it increases as it goes up and to the right
- Wed Oct 23, 2019 12:38 pm
- Forum: Resonance Structures
- Topic: polarity
- Replies: 1
- Views: 98
polarity
Do different resonance structures affect the polarity of molecules?
- Wed Oct 23, 2019 12:33 pm
- Forum: Ionic & Covalent Bonds
- Topic: Difference Between Ionic and Covalent
- Replies: 8
- Views: 1018
Re: Difference Between Ionic and Covalent
Ionic bonds occur after electrons have been completely transferred over while covalent bonds are the sharing of ekectrons.
- Wed Oct 23, 2019 12:30 pm
- Forum: Lewis Structures
- Topic: Lewis Structure angles
- Replies: 3
- Views: 248
Re: Lewis Structure angles
Probably try to be as accurate as possible but you don't have to be exact. As long as you have the right attempt, you don't need to use a protractor or anything that specific
- Wed Oct 16, 2019 12:28 pm
- Forum: Properties of Light
- Topic: Concept of Rainbows
- Replies: 1
- Views: 168
Re: Concept of Rainbows
Possibly because the light is not diffracted enough due to the size of the water droplet, or the rainbow could be very small and hard to notice
- Wed Oct 16, 2019 12:26 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: What is Molarity?
- Replies: 11
- Views: 978
Re: What is Molarity?
Molarity is moles/liters. It refers to the concentration of atoms/molecules in a solvent. When something refers to transferring a specific molarity of a substance, it is talking about a certain concentration of that liquid
- Wed Oct 16, 2019 12:22 pm
- Forum: SI Units, Unit Conversions
- Topic: Chemistry Grades
- Replies: 4
- Views: 216
Re: Chemistry Grades
Our TA said grades would be input as soon as assignments go in and they can be checked on MyUCLA
- Wed Oct 16, 2019 12:19 pm
- Forum: DeBroglie Equation
- Topic: ionization energy
- Replies: 2
- Views: 196
Re: ionization energy
Ionization energy is the amount of energy it requires to remove an electron from an atom's valence shell, which is similar to the definition of work function
- Wed Oct 16, 2019 12:17 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Question regarding definition of molecules
- Replies: 5
- Views: 529
Re: Question regarding definition of molecules
The constant refers to the amount (6.022*10^23) in a mole of a unit. It could be either a molecule, or an atom as long as it is 1 unit.
- Sun Oct 13, 2019 8:51 pm
- Forum: SI Units, Unit Conversions
- Topic: knowing how many sig figs to use
- Replies: 17
- Views: 769
Re: knowing how many sig figs to use
Sig Figs are important and you should keep them in mind while you're doing a problem but only round at the end
- Sun Oct 13, 2019 8:49 pm
- Forum: Properties of Light
- Topic: Wavelength
- Replies: 3
- Views: 101
Wavelength
Why does a shorter wavelength mean there is more energy?
- Sun Oct 13, 2019 8:36 pm
- Forum: Trends in The Periodic Table
- Topic: electronegativity
- Replies: 10
- Views: 3278
Re: electronegativity
Electronegativity is the strength atoms have in puling other electrons to complete their valence shell