k = A exp( -EA/RT )
this shows how it can be changed
Search found 95 matches
- Thu Mar 12, 2020 12:20 pm
- Forum: General Rate Laws
- Topic: Factors Affecting k
- Replies: 83
- Views: 4543
- Wed Mar 11, 2020 7:34 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Temperature and Reaction Rate
- Replies: 6
- Views: 442
Re: Temperature and Reaction Rate
according to k = A e^( -EA/RT ), if T increases, k increases and if T decreases, k decreases
- Tue Mar 10, 2020 9:52 pm
- Forum: Administrative Questions and Class Announcements
- Topic: What is the plan for the final?
- Replies: 16
- Views: 1001
Re: What is the plan for the final?
We're going to have to wait until he emails us.
- Tue Mar 10, 2020 9:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Homework 10
- Replies: 11
- Views: 646
Re: Homework 10
Our TAs will eventually email us to tell us what to do.
- Tue Mar 10, 2020 9:48 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Return
- Replies: 20
- Views: 1148
Re: Test 2 Return
We are going to have to wait until Lavelle/TA's email us explaining what's going down. Maybe they'll email us the tests back?
- Tue Mar 10, 2020 9:44 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Email Announcement
- Replies: 8
- Views: 673
Re: Email Announcement
I think he will send an email tonight regarding at least lecture tomorrow
- Thu Mar 05, 2020 4:26 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Inert Metals
- Replies: 4
- Views: 327
Re: Inert Metals
I think we could use either, but Pt(s) is more commonly used
- Thu Mar 05, 2020 4:25 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Order
- Replies: 8
- Views: 573
Re: Cell Diagram Order
the anode, which in this case would be Au(s) as it is a solid conductor, should be on the left while its aqueous form, Au 3+(aq), should be on the inside.
The correct order is Au(s)|Au3+(aq)||
The correct order is Au(s)|Au3+(aq)||
- Thu Mar 05, 2020 4:21 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6M.1
- Replies: 1
- Views: 140
Re: 6M.1
I think it's the anode because it is being oxidized from Cu (s) to Cu2+ (aq), and the anode is always oxidized.
- Tue Mar 03, 2020 1:54 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Platinum
- Replies: 6
- Views: 384
Re: Platinum
Pt or another inert conducting metal solid is used when there is not an inert conducting metal solid in the equation.
- Tue Mar 03, 2020 1:51 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: finding moles
- Replies: 6
- Views: 439
Re: finding moles
The moles (n) refers to the moles of electrons being transferred.
You'll need to balance the half-reactions in order to find the moles of electrons (n).
You'll need to balance the half-reactions in order to find the moles of electrons (n).
- Mon Mar 02, 2020 8:20 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Review Sessions
- Replies: 6
- Views: 343
Re: Final Review Sessions
Yeah, he'll announce soon in lecture
- Fri Feb 28, 2020 4:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2
- Replies: 5
- Views: 342
Re: Test 2
The last part of thermodynamics (the part that was not on the midterm) and electrochemistry
- Thu Feb 27, 2020 11:00 pm
- Forum: Balancing Redox Reactions
- Topic: Acidic/Basic Solutions
- Replies: 3
- Views: 229
Re: Acidic/Basic Solutions
I feel like we would be told if it is an acidic or basic solution.
- Thu Feb 27, 2020 5:41 pm
- Forum: Administrative Questions and Class Announcements
- Topic: UA sessions
- Replies: 5
- Views: 312
Re: UA sessions
I think it depends on the UA and what type of session is it (workshop, step-up, drop-in)
- Thu Feb 27, 2020 5:29 pm
- Forum: General Science Questions
- Topic: Test 2
- Replies: 16
- Views: 953
Re: Test 2
the last bit of thermodynamics and electrochemistry
- Tue Feb 25, 2020 11:22 am
- Forum: Balancing Redox Reactions
- Topic: reducing agent
- Replies: 5
- Views: 314
Re: reducing agent
The reducing agent is the substance that causes another substance to be reduced in a redox reaction. The reducing agent itself is then oxidized.
Reducing agent: gets oxidized, causes another agent to be reduced
Oxidizing agent: gets reduced, causes another agent to be oxidized
Reducing agent: gets oxidized, causes another agent to be reduced
Oxidizing agent: gets reduced, causes another agent to be oxidized
- Fri Feb 21, 2020 4:11 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation Numbers
- Replies: 9
- Views: 624
Re: Oxidation Numbers
this website sums up some rules:
https://www.thoughtco.com/rules-for-assigning-oxidation-numbers-607567
https://www.thoughtco.com/rules-for-assigning-oxidation-numbers-607567
- Fri Feb 21, 2020 2:46 pm
- Forum: Balancing Redox Reactions
- Topic: oxidation
- Replies: 3
- Views: 304
Re: oxidation
Oxidation numbers are related to the charge in that you use the charges to find the oxidation numbers. Primarily, we use known oxidation numbers in a molecule, such as H2O, where we know the oxidation number of O is-2, so each H should be +1, meaning the oxidation number of the molecule will be 0, a...
- Thu Feb 20, 2020 8:13 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cells
- Replies: 8
- Views: 440
Re: Galvanic Cells
A galvanic cell is used to produce electricity.
also, a galvanic cell is also known as a voltaic cell.
also, a galvanic cell is also known as a voltaic cell.
- Thu Feb 20, 2020 10:08 am
- Forum: Administrative Questions and Class Announcements
- Topic: Number of Chemistry Community Posts
- Replies: 2
- Views: 215
Re: Number of Chemistry Community Posts
at top left, go to:
Quick links
»Your posts
Quick links
»Your posts
- Thu Feb 20, 2020 10:02 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Charge Buildup
- Replies: 3
- Views: 268
Re: Charge Buildup
A charge buildup in the anode solution means that electrons will no longer transfer from anode to cathode. The salt bridge is used to prevent this charge buildup by neutralizing the anode solution.
- Wed Feb 12, 2020 9:07 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Negative work
- Replies: 14
- Views: 892
Re: Negative work
When a system does work
- Mon Feb 10, 2020 10:11 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Molar Concentration Direction.
- Replies: 2
- Views: 156
Re: Molar Concentration Direction.
Well, we know the initial concentrations of N2 and O2, and since we are not told anything about N2O, we assume its initial concentration is zero. N2 and O2 must decrease by some amount, which will become the concentration of N2O at equilibrium. Since the stoichiometric coefficient of N2 is 2 in the ...
- Mon Feb 10, 2020 10:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Correct Calculator for Midterm
- Replies: 2
- Views: 293
Re: Correct Calculator for Midterm
Any scientific calculator is fine
- Mon Feb 10, 2020 6:03 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Review Session #3b
- Replies: 2
- Views: 109
Re: Review Session #3b
I used q=mΔHfus and rearranged to ΔHfus=q/m
but the question says that half of the ice cream melted meaning ΔHfus=q/(0.5m)
And I think enthalpy is usually in kJ/mol, but it depends on what is given in the problem and what is asked for.
but the question says that half of the ice cream melted meaning ΔHfus=q/(0.5m)
And I think enthalpy is usually in kJ/mol, but it depends on what is given in the problem and what is asked for.
- Mon Feb 10, 2020 5:50 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Double Greater than Sign
- Replies: 2
- Views: 609
Re: Double Greater than Sign
">>" means much greater
The entropy of a gas is much greater than the entropy of a liquid, which is greater than the entropy of a solid.
The entropy of a gas is much greater than the entropy of a liquid, which is greater than the entropy of a solid.
- Tue Feb 04, 2020 1:00 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed system
- Replies: 7
- Views: 348
Re: closed system
It is a closed system because there will be no exchange of matter, only heat. However, it is not isolated as there can be an exchange of heat.
- Tue Feb 04, 2020 12:58 pm
- Forum: Calculating Work of Expansion
- Topic: Identifying constant pressure in a question
- Replies: 3
- Views: 197
Re: Identifying constant pressure in a question
also, be aware that if it just says "an external pressure of [blank]" then it will be constant
- Mon Feb 03, 2020 5:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: when are your #of posts on CC collected each week?
- Replies: 4
- Views: 180
Re: when are your #of posts on CC collected each week?
The cutoff is Sunday at 11:59 pm every week I believe.
- Mon Feb 03, 2020 5:25 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: ∆U
- Replies: 8
- Views: 355
Re: ∆U
∆U= (U final-U initial)= change in internal energy
- Mon Feb 03, 2020 3:16 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: endo vs exo
- Replies: 8
- Views: 176
Re: endo vs exo
for breaking a bond, the sign of delta H would be positive as energy is required (endothermic). This is because of the fact that bonds don't break spontaneously, so in order to break it energy is required
- Fri Jan 31, 2020 4:41 pm
- Forum: General Science Questions
- Topic: Increasing Entropy
- Replies: 5
- Views: 335
Re: Increasing Entropy
the universe is just getting infinitely more disordered as time goes by
- Tue Jan 28, 2020 11:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test One
- Replies: 2
- Views: 98
Re: Test One
I think we'll receive it in our next discussion session. That's how it worked last quarter in 14A with Lavelle at least.
- Tue Jan 28, 2020 11:09 pm
- Forum: Phase Changes & Related Calculations
- Topic: Calculating Work
- Replies: 6
- Views: 176
Re: Calculating Work
When work is done on a system, it is positive. When work is done by a system, it is negative
- Tue Jan 28, 2020 11:04 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Delta U
- Replies: 6
- Views: 254
Re: Delta U
Also, make sure to include the sign unless specified not to.
- Tue Jan 28, 2020 12:32 pm
- Forum: Ideal Gases
- Topic: Ideal Gas
- Replies: 4
- Views: 188
Re: Ideal Gas
collisions are ignored and treated as elastic.
- Tue Jan 28, 2020 12:28 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: qp vs qv
- Replies: 6
- Views: 317
Re: qp vs qv
The only real difference is that qp occurs under constant pressure and qv occurs under constant volume.
- Tue Jan 28, 2020 12:26 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Units
- Replies: 5
- Views: 171
Re: Units
I'd say use J unless kJ is asked for. It also might depend on the sig figs of the final answer.
- Tue Jan 21, 2020 10:47 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Approximation
- Replies: 6
- Views: 219
Re: Approximation
I believe smaller than 10^-3
- Tue Jan 21, 2020 10:27 am
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Prepping for Test
- Replies: 6
- Views: 304
Re: Prepping for Test
Do the homework problems assigned to us so far for chemical equilibrium and acid-base equilibrium. This is what the test will cover.
- Mon Jan 20, 2020 7:49 pm
- Forum: Student Social/Study Group
- Topic: Number of Chemistry Community Posts
- Replies: 45
- Views: 2399
Re: Number of Chemistry Community Posts
look at the posts you made and count the posts made in January 2020, which are your post so far this quarter
- Mon Jan 20, 2020 7:44 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium Questions and Sig Figs
- Replies: 6
- Views: 119
Re: Equilibrium Questions and Sig Figs
I agree with the last user's post in that it is best to round to the number of given sig figs at the very end. When dealing with pH however, the sig figs are typically calculated differently (calculated in the way of a logarithm) which I believe is 3 sig figs usually. For pH, the sig figs in the gi...
- Mon Jan 20, 2020 7:22 pm
- Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
- Topic: Test 1 material
- Replies: 3
- Views: 667
Re: Test 1 material
no, only what we covered in chemical equilibrium and acids and bases
- Mon Jan 20, 2020 7:19 pm
- Forum: Student Social/Study Group
- Topic: Test 1
- Replies: 9
- Views: 546
Re: Test 1
do problems from the textbook to help prepare. Chemical equilibrium and acids and bases are what will be on the test.
- Wed Jan 15, 2020 6:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka + Kb
- Replies: 6
- Views: 135
Re: Ka + Kb
Another way to see it is that Ka+Kb=Kw, which is 14. If ka increases, then Kb must decrease in order to be equal to 14. If Kb increases, then Ka must decrease in order to be equal to 14.
- Tue Jan 14, 2020 10:49 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp vs Kc
- Replies: 4
- Views: 107
Re: Kp vs Kc
I think it depends on what is given.
- Tue Jan 14, 2020 5:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Table
- Replies: 8
- Views: 270
Re: ICE Table
Yes you can. ICE tables are really useful for chemistry in general.
- Tue Jan 14, 2020 5:10 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Grading
- Replies: 8
- Views: 561
Re: Grading
Just make sure you post 5 times per week. Those posts can consist of questions asked and/or replies to other people's questions.
- Tue Jan 14, 2020 5:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5l.13
- Replies: 2
- Views: 130
Re: 5l.13
I'd like to add on that the equilibrium constant for Cl2 is smaller than the equilibrium constant of F2, meaning the reactant is more favored in the Cl2 chemical equation.
- Thu Jan 09, 2020 4:15 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: confused about ice table
- Replies: 5
- Views: 135
Re: confused about ice table
if you are still having trouble understanding, I would recommend looking at the 4th module on the 14B webstie (Chemical Equilibrium Part 3 Video Module) or youtube.
- Thu Jan 09, 2020 4:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE Table Ratios
- Replies: 7
- Views: 221
Re: ICE Table Ratios
I don't think it matters, just as long it is in accordance with the balanced chemical equation.
- Wed Jan 08, 2020 11:00 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Liquids in Equilibrium Constant
- Replies: 3
- Views: 142
Re: Liquids in Equilibrium Constant
We only include gases (g) and aqueous (aq) substances in calculating equilibrium constants.
- Wed Jan 08, 2020 10:59 pm
- Forum: Ideal Gases
- Topic: Understanding Q
- Replies: 19
- Views: 681
Re: Understanding Q
Q is just ratio of the products and reactants when not in equilibrium, but is calculated the same way as K.
- Wed Jan 08, 2020 10:57 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Aqueous Compounds
- Replies: 3
- Views: 119
Re: Aqueous Compounds
We only omit compounds when they are explicitly liquid or solid. Everything else we include in calculating K and Q.
- Sun Dec 08, 2019 10:16 am
- Forum: Biological Examples
- Topic: Cis vs Trans
- Replies: 3
- Views: 292
Re: Cis vs Trans
cis means the same ligands are on the same side while trans means the same ligands are across from each other, separated by the central atom.
The terms tell us about the compound's geometry
The terms tell us about the compound's geometry
- Fri Dec 06, 2019 9:34 am
- Forum: Bronsted Acids & Bases
- Topic: Amphiprotic vs amphoteric
- Replies: 3
- Views: 262
Re: Amphiprotic vs amphoteric
Amphoteric means that a molecule can act as either an acid or a base. Amphiprotic describes a molecule that can donate or accept a proton. Water is a good example of an amphoteric molecule that is also amphiprotic. Also, although an amphiprotic molecule is always amphoteric, an amphoteric molecule i...
- Thu Dec 05, 2019 4:59 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination number
- Replies: 6
- Views: 192
Re: coordination number
to add on, be aware of polydentate ligands bonded to the metal as they also contribute to the coordination number. For example, if a metal is only bonded to 1 bidentate ligand than the coordination number would be 2 as the ligand is bonded to the metal 2 times
- Thu Dec 05, 2019 11:50 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: London disperson
- Replies: 6
- Views: 266
Re: London disperson
To add on, at some point, LDF can be stronger than some other intermolecular forces if the molecules is large
- Thu Dec 05, 2019 7:57 am
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Calculations
- Replies: 1
- Views: 97
Re: Calculations
We won't be using ICE table until 14B.
- Thu Dec 05, 2019 7:52 am
- Forum: Naming
- Topic: Naming Versions
- Replies: 2
- Views: 102
Re: Naming Versions
Either one is acceptable.
- Tue Dec 03, 2019 4:08 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Final Material
- Replies: 2
- Views: 253
Re: Final Material
I don't think so as I don't recall Prof. Lavelle going over it in lecture
- Tue Dec 03, 2019 4:06 pm
- Forum: General Science Questions
- Topic: Week 10 Classes
- Replies: 7
- Views: 498
Re: Week 10 Classes
Finish up new material wednesday, review friday
- Mon Dec 02, 2019 7:36 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Past exams
- Replies: 7
- Views: 669
Re: Past exams
You can try asking people who have taken the class before and see if they have any past exams and are generous enough to give them to you.
- Mon Dec 02, 2019 7:33 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Difficulty
- Replies: 14
- Views: 823
Re: Difficulty
From a scale of 1-10, with 10 being the most difficult, I'd say this class was a 7.5. It is difficult as I only had a limited background with chem and feels really accelerated, but it is manageable if you seek help (review sessions, UA workshops/step-up, PLF sessions, looking up concepts).
- Mon Dec 02, 2019 6:19 pm
- Forum: Student Social/Study Group
- Topic: Lavelle's Lecture Review Questions
- Replies: 3
- Views: 247
Re: Lavelle's Lecture Review Questions
I would assume it would be the same questions for each lecture.
- Sat Nov 30, 2019 8:40 am
- Forum: General Science Questions
- Topic: test taking nervousness
- Replies: 19
- Views: 997
Re: test taking nervousness
Maybe try doing practice problems in test-like situations under a time constraint so you can be more used to actual test-taking.
- Sat Nov 30, 2019 8:37 am
- Forum: General Science Questions
- Topic: test bank
- Replies: 2
- Views: 126
Re: test bank
There is a test bank at the CPO office in SAC.
- Sat Nov 30, 2019 8:36 am
- Forum: General Science Questions
- Topic: study tips for the final
- Replies: 3
- Views: 210
Re: study tips for the final
There will most likely be several review sessions for the final like the ones that we had for the midterm. Lavelle said they were still working on reserving rooms for it last week, so he'll probably tell us about it this coming week 10.
- Sat Nov 30, 2019 8:32 am
- Forum: Bronsted Acids & Bases
- Topic: Bronsted Acid and base
- Replies: 8
- Views: 468
Re: Bronsted Acid and base
Bronstad acid and bases have to do with protons, while Lewis acids and bases have to do with electrons
- Thu Nov 28, 2019 7:56 pm
- Forum: Naming
- Topic: -ido vs -o
- Replies: 5
- Views: 313
Re: -ido vs -o
-ido and -o mean the same thing, it's just that -ido is now the "correct" version to use
- Tue Nov 26, 2019 8:00 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test #2 handback
- Replies: 11
- Views: 693
Re: Test #2 handback
If you have discussion this week, then this week. If not, then next week most likely.
- Tue Nov 26, 2019 6:56 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2
- Replies: 7
- Views: 245
Re: Test 2
The next time we see our TA's I believe
- Tue Nov 26, 2019 6:54 pm
- Forum: Bronsted Acids & Bases
- Topic: Definition
- Replies: 5
- Views: 159
Re: Definition
A bronsted acid donates a proton
A lewis acid accepts an electron pair
A bronsted base accepts a proton
A lewis base donates an electron pair
A lewis acid accepts an electron pair
A bronsted base accepts a proton
A lewis base donates an electron pair
- Tue Nov 26, 2019 5:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Video Modules
- Replies: 5
- Views: 236
Re: Video Modules
We won't be posting any more video modules, unfortunately. If you need more help understanding the topic, step-ups and UA workshops are your best bet
- Tue Nov 26, 2019 5:08 pm
- Forum: Student Social/Study Group
- Topic: Test 2 and Final
- Replies: 18
- Views: 862
Re: Test 2 and Final
My guess is that the TA's will give back test 2 next time we see them
- Thu Nov 21, 2019 10:44 am
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Strongest force
- Replies: 6
- Views: 294
Re: Strongest force
I think generally for small molecules, hydrogen bonds are the strongest, then dipole-dipole, and London dispersion forces as the weakest. However, as the size of the molecule increases, London dispersion forces can dominate over other forces. I'm not sure if ion-dipole forces are considered an inter...
- Thu Nov 21, 2019 10:29 am
- Forum: Lewis Structures
- Topic: I3- Lewis Structure
- Replies: 2
- Views: 260
Re: I3- Lewis Structure
You always want to choose the most stable resonance structure, which in this case would be the first lewis structure.
- Thu Nov 21, 2019 10:26 am
- Forum: Dipole Moments
- Topic: Melting points
- Replies: 15
- Views: 1269
Re: Melting points
I think only intermolecular forces affect melting/boiling points.
- Thu Nov 21, 2019 10:24 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Periodic Trends
- Replies: 8
- Views: 652
Re: Periodic Trends
Polarizing power increases going up and to the right on the periodic table
Polarizability increases going down and to the left on the periodic table
Polarizability increases going down and to the left on the periodic table
- Thu Nov 21, 2019 10:06 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polarity and Number of Bonds
- Replies: 3
- Views: 207
Re: Polarity and Number of Bonds
I think a double bond will make the molecule more polar, say in C=O compared to C—O, as the C=O has a π bond. But for NO3-, the resonance hybrid structure would have it's partial charges cancel out, resulting in a nonpolar molecule.
- Tue Nov 12, 2019 5:45 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Test 2
- Replies: 3
- Views: 93
Re: Test 2
I think it'll be everything after the midterm up until this Friday.
- Tue Nov 12, 2019 5:39 pm
- Forum: Octet Exceptions
- Topic: expanded octet
- Replies: 7
- Views: 632
Re: expanded octet
If the element is in the 3rd row or under in the periodic table, then it can have an expanded octet as the third row has access to the d-block, which can hold ten more electrons if needed.
- Tue Nov 12, 2019 5:34 pm
- Forum: Resonance Structures
- Topic: Writing Out Resonance
- Replies: 3
- Views: 218
Re: Writing Out Resonance
It'll be most safe to write out every resonance structure
- Tue Nov 12, 2019 5:33 pm
- Forum: Properties of Light
- Topic: Chemistry Community Posts
- Replies: 10
- Views: 762
Re: Chemistry Community Posts
Can confirm, 5 times a week
- Tue Nov 12, 2019 5:23 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge
- Replies: 7
- Views: 437
Re: Formal Charge
There are several equations you can use.
The one Lavelle showed us was: formal charge=valence electrons of atom-(lone pairs electrons +shared electrons/2) or FC=Ve-(L+S/2)
I personally like using: formal charge=valence electrons of atom-(bonds + dots) or FC=Ve-(B+D)
The one Lavelle showed us was: formal charge=valence electrons of atom-(lone pairs electrons +shared electrons/2) or FC=Ve-(L+S/2)
I personally like using: formal charge=valence electrons of atom-(bonds + dots) or FC=Ve-(B+D)
- Mon Nov 04, 2019 7:36 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: "Polarizing power" in textbook
- Replies: 2
- Views: 191
Re: "Polarizing power" in textbook
You're right. I see it as an atom with a small atomic radius holds its electrons more closely and is more willing to take electrons from others, while an atom with a large atomic radius holds its electrons more loosely, so its easier to take an electron away from it. Also, keep the periodic trends o...
- Mon Nov 04, 2019 7:27 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Electron Configuration
- Replies: 5
- Views: 293
Re: Midterm Electron Configuration
I remember Lavelle saying that we only need to know the s-block, p-block, and the first row of the d-block (3d).
- Thu Oct 31, 2019 11:38 am
- Forum: DeBroglie Equation
- Topic: Confused about equations
- Replies: 7
- Views: 400
Re: Confused aout equations
c= λv and E=hv apply to light (photons). I think De Broglie's (λ=h/(mv)) applies to particles (electrons), as do Heisenberg's and Schrodinger's equations.
- Fri Oct 25, 2019 5:21 pm
- Forum: Lewis Structures
- Topic: Video Modules
- Replies: 11
- Views: 391
Re: Video Modules
I think the ones already posted are the only ones that are going to be posted.
- Fri Oct 18, 2019 2:47 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Exceptions
- Replies: 4
- Views: 216
Re: Exceptions
I think these 2 are the only ones we need to know for Chem 14A.
- Thu Oct 10, 2019 6:51 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Test Equation Sheets
- Replies: 5
- Views: 204
Re: Test Equation Sheets
We will get an equation sheet with a list of conversions we need with the test, as well as a periodic table, so you don't really have to memorize them.
- Thu Oct 10, 2019 6:34 pm
- Forum: Empirical & Molecular Formulas
- Topic: Mass Percent Calculations
- Replies: 4
- Views: 189
Re: Mass Percent Calculations
Wesley explained it very well. Then, once you have the mass percentage of each element, you can do the rest of the problem normally.
- Thu Oct 10, 2019 6:28 pm
- Forum: Student Social/Study Group
- Topic: Pen or Pencil for Homework Problems?
- Replies: 8
- Views: 435
Re: Pen or Pencil for Homework Problems?
I'd assume It wouldn't matter whether you did the problems with pen or pencil.
- Sun Oct 06, 2019 4:14 pm
- Forum: Balancing Chemical Reactions
- Topic: Naming/Polyatomic ions
- Replies: 4
- Views: 197
Re: Naming/Polyatomic ions
I don't think so. They are not in the objectives listed in Outline 1: Review of Chemical & Physical Principles. I have a feeling it'll be more like the first 4 learning modules we did.