Search found 95 matches

by Daniel Toscano 1L
Thu Mar 12, 2020 12:20 pm
Forum: General Rate Laws
Topic: Factors Affecting k
Replies: 16
Views: 158

Re: Factors Affecting k

k = A exp( -EA/RT )
this shows how it can be changed
by Daniel Toscano 1L
Wed Mar 11, 2020 7:34 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Temperature and Reaction Rate
Replies: 6
Views: 92

Re: Temperature and Reaction Rate

according to k = A e^( -EA/RT ), if T increases, k increases and if T decreases, k decreases
by Daniel Toscano 1L
Tue Mar 10, 2020 9:52 pm
Forum: Administrative Questions and Class Announcements
Topic: What is the plan for the final?
Replies: 16
Views: 257

Re: What is the plan for the final?

We're going to have to wait until he emails us.
by Daniel Toscano 1L
Tue Mar 10, 2020 9:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework 10
Replies: 11
Views: 125

Re: Homework 10

Our TAs will eventually email us to tell us what to do.
by Daniel Toscano 1L
Tue Mar 10, 2020 9:48 pm
Forum: Balancing Redox Reactions
Topic: Test 2 Return
Replies: 20
Views: 341

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?
by Daniel Toscano 1L
Tue Mar 10, 2020 9:44 pm
Forum: Administrative Questions and Class Announcements
Topic: Email Announcement
Replies: 8
Views: 218

Re: Email Announcement

I think he will send an email tonight regarding at least lecture tomorrow
by Daniel Toscano 1L
Thu Mar 05, 2020 4:26 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Inert Metals
Replies: 4
Views: 36

Re: Inert Metals

I think we could use either, but Pt(s) is more commonly used
by Daniel Toscano 1L
Thu Mar 05, 2020 4:25 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram Order
Replies: 8
Views: 92

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)||
by Daniel Toscano 1L
Thu Mar 05, 2020 4:21 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6M.1
Replies: 1
Views: 29

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.
by Daniel Toscano 1L
Tue Mar 03, 2020 1:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Platinum
Replies: 6
Views: 42

Re: Platinum

Pt or another inert conducting metal solid is used when there is not an inert conducting metal solid in the equation.
by Daniel Toscano 1L
Tue Mar 03, 2020 1:51 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: finding moles
Replies: 6
Views: 136

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).
by Daniel Toscano 1L
Mon Mar 02, 2020 8:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Review Sessions
Replies: 6
Views: 68

Re: Final Review Sessions

Yeah, he'll announce soon in lecture
by Daniel Toscano 1L
Fri Feb 28, 2020 4:02 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 5
Views: 71

Re: Test 2

The last part of thermodynamics (the part that was not on the midterm) and electrochemistry
by Daniel Toscano 1L
Thu Feb 27, 2020 11:00 pm
Forum: Balancing Redox Reactions
Topic: Acidic/Basic Solutions
Replies: 3
Views: 39

Re: Acidic/Basic Solutions

I feel like we would be told if it is an acidic or basic solution.
by Daniel Toscano 1L
Thu Feb 27, 2020 5:41 pm
Forum: Administrative Questions and Class Announcements
Topic: UA sessions
Replies: 5
Views: 54

Re: UA sessions

I think it depends on the UA and what type of session is it (workshop, step-up, drop-in)
by Daniel Toscano 1L
Thu Feb 27, 2020 5:29 pm
Forum: General Science Questions
Topic: Test 2
Replies: 16
Views: 313

Re: Test 2

the last bit of thermodynamics and electrochemistry
by Daniel Toscano 1L
Tue Feb 25, 2020 11:22 am
Forum: Balancing Redox Reactions
Topic: reducing agent
Replies: 5
Views: 63

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
by Daniel Toscano 1L
Fri Feb 21, 2020 2:46 pm
Forum: Balancing Redox Reactions
Topic: oxidation
Replies: 3
Views: 56

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...
by Daniel Toscano 1L
Thu Feb 20, 2020 8:13 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic Cells
Replies: 8
Views: 52

Re: Galvanic Cells

A galvanic cell is used to produce electricity.
also, a galvanic cell is also known as a voltaic cell.
by Daniel Toscano 1L
Thu Feb 20, 2020 10:08 am
Forum: Administrative Questions and Class Announcements
Topic: Number of Chemistry Community Posts
Replies: 2
Views: 43

Re: Number of Chemistry Community Posts

at top left, go to:
Quick links
»Your posts
by Daniel Toscano 1L
Thu Feb 20, 2020 10:02 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Charge Buildup
Replies: 3
Views: 38

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.
by Daniel Toscano 1L
Wed Feb 12, 2020 9:07 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Negative work
Replies: 14
Views: 238

Re: Negative work

When a system does work
by Daniel Toscano 1L
Mon Feb 10, 2020 10:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Molar Concentration Direction.
Replies: 2
Views: 33

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 ...
by Daniel Toscano 1L
Mon Feb 10, 2020 10:04 pm
Forum: Administrative Questions and Class Announcements
Topic: Correct Calculator for Midterm
Replies: 2
Views: 131

Re: Correct Calculator for Midterm

Any scientific calculator is fine
by Daniel Toscano 1L
Mon Feb 10, 2020 6:03 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Review Session #3b
Replies: 2
Views: 36

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.
by Daniel Toscano 1L
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: 23

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.
by Daniel Toscano 1L
Tue Feb 04, 2020 1:00 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed system
Replies: 7
Views: 76

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.
by Daniel Toscano 1L
Tue Feb 04, 2020 12:58 pm
Forum: Calculating Work of Expansion
Topic: Identifying constant pressure in a question
Replies: 3
Views: 56

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
by Daniel Toscano 1L
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: 116

Re: when are your #of posts on CC collected each week?

The cutoff is Sunday at 11:59 pm every week I believe.
by Daniel Toscano 1L
Mon Feb 03, 2020 5:25 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: ∆U
Replies: 8
Views: 89

Re: ∆U

∆U= (U final-U initial)= change in internal energy
by Daniel Toscano 1L
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: 43

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
by Daniel Toscano 1L
Fri Jan 31, 2020 4:41 pm
Forum: General Science Questions
Topic: Increasing Entropy
Replies: 5
Views: 88

Re: Increasing Entropy

the universe is just getting infinitely more disordered as time goes by
by Daniel Toscano 1L
Tue Jan 28, 2020 11:12 pm
Forum: Administrative Questions and Class Announcements
Topic: Test One
Replies: 2
Views: 40

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.
by Daniel Toscano 1L
Tue Jan 28, 2020 11:09 pm
Forum: Phase Changes & Related Calculations
Topic: Calculating Work
Replies: 6
Views: 61

Re: Calculating Work

When work is done on a system, it is positive. When work is done by a system, it is negative
by Daniel Toscano 1L
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: 55

Re: Delta U

Also, make sure to include the sign unless specified not to.
by Daniel Toscano 1L
Tue Jan 28, 2020 12:32 pm
Forum: Ideal Gases
Topic: Ideal Gas
Replies: 4
Views: 55

Re: Ideal Gas

collisions are ignored and treated as elastic.
by Daniel Toscano 1L
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: 69

Re: qp vs qv

The only real difference is that qp occurs under constant pressure and qv occurs under constant volume.
by Daniel Toscano 1L
Tue Jan 28, 2020 12:26 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Units
Replies: 5
Views: 52

Re: Units

I'd say use J unless kJ is asked for. It also might depend on the sig figs of the final answer.
by Daniel Toscano 1L
Tue Jan 21, 2020 10:47 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Approximation
Replies: 6
Views: 40

Re: Approximation

I believe smaller than 10^-3
by Daniel Toscano 1L
Tue Jan 21, 2020 10:27 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Prepping for Test
Replies: 6
Views: 69

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.
by Daniel Toscano 1L
Mon Jan 20, 2020 7:49 pm
Forum: Student Social/Study Group
Topic: Number of Chemistry Community Posts
Replies: 33
Views: 718

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
by Daniel Toscano 1L
Mon Jan 20, 2020 7:44 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium Questions and Sig Figs
Replies: 6
Views: 67

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...
by Daniel Toscano 1L
Mon Jan 20, 2020 7:22 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Test 1 material
Replies: 3
Views: 109

Re: Test 1 material

no, only what we covered in chemical equilibrium and acids and bases
by Daniel Toscano 1L
Mon Jan 20, 2020 7:19 pm
Forum: Student Social/Study Group
Topic: Test 1
Replies: 9
Views: 149

Re: Test 1

do problems from the textbook to help prepare. Chemical equilibrium and acids and bases are what will be on the test.
by Daniel Toscano 1L
Wed Jan 15, 2020 6:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ka + Kb
Replies: 6
Views: 40

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.
by Daniel Toscano 1L
Tue Jan 14, 2020 10:49 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kp vs Kc
Replies: 4
Views: 41

Re: Kp vs Kc

I think it depends on what is given.
by Daniel Toscano 1L
Tue Jan 14, 2020 5:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Table
Replies: 8
Views: 91

Re: ICE Table

Yes you can. ICE tables are really useful for chemistry in general.
by Daniel Toscano 1L
Tue Jan 14, 2020 5:10 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading
Replies: 8
Views: 158

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.
by Daniel Toscano 1L
Tue Jan 14, 2020 5:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5l.13
Replies: 2
Views: 53

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.
by Daniel Toscano 1L
Thu Jan 09, 2020 4:15 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: confused about ice table
Replies: 5
Views: 43

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.
by Daniel Toscano 1L
Thu Jan 09, 2020 4:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Table Ratios
Replies: 7
Views: 76

Re: ICE Table Ratios

I don't think it matters, just as long it is in accordance with the balanced chemical equation.
by Daniel Toscano 1L
Wed Jan 08, 2020 11:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Liquids in Equilibrium Constant
Replies: 3
Views: 39

Re: Liquids in Equilibrium Constant

We only include gases (g) and aqueous (aq) substances in calculating equilibrium constants.
by Daniel Toscano 1L
Wed Jan 08, 2020 10:59 pm
Forum: Ideal Gases
Topic: Understanding Q
Replies: 19
Views: 176

Re: Understanding Q

Q is just ratio of the products and reactants when not in equilibrium, but is calculated the same way as K.
by Daniel Toscano 1L
Wed Jan 08, 2020 10:57 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Aqueous Compounds
Replies: 3
Views: 35

Re: Aqueous Compounds

We only omit compounds when they are explicitly liquid or solid. Everything else we include in calculating K and Q.
by Daniel Toscano 1L
Sun Dec 08, 2019 10:16 am
Forum: Biological Examples
Topic: Cis vs Trans
Replies: 3
Views: 119

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
by Daniel Toscano 1L
Fri Dec 06, 2019 9:34 am
Forum: Bronsted Acids & Bases
Topic: Amphiprotic vs amphoteric
Replies: 3
Views: 63

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...
by Daniel Toscano 1L
Thu Dec 05, 2019 4:59 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coordination number
Replies: 6
Views: 74

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
by Daniel Toscano 1L
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: 51

Re: London disperson

To add on, at some point, LDF can be stronger than some other intermolecular forces if the molecules is large
by Daniel Toscano 1L
Thu Dec 05, 2019 7:57 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Calculations
Replies: 1
Views: 26

Re: Calculations

We won't be using ICE table until 14B.
by Daniel Toscano 1L
Thu Dec 05, 2019 7:52 am
Forum: Naming
Topic: Naming Versions
Replies: 2
Views: 52

Re: Naming Versions

Either one is acceptable.
by Daniel Toscano 1L
Tue Dec 03, 2019 4:08 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Final Material
Replies: 2
Views: 106

Re: Final Material

I don't think so as I don't recall Prof. Lavelle going over it in lecture
by Daniel Toscano 1L
Tue Dec 03, 2019 4:06 pm
Forum: General Science Questions
Topic: Week 10 Classes
Replies: 7
Views: 169

Re: Week 10 Classes

Finish up new material wednesday, review friday
by Daniel Toscano 1L
Mon Dec 02, 2019 7:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Past exams
Replies: 7
Views: 141

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.
by Daniel Toscano 1L
Mon Dec 02, 2019 7:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Difficulty
Replies: 14
Views: 199

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).
by Daniel Toscano 1L
Mon Dec 02, 2019 6:19 pm
Forum: Student Social/Study Group
Topic: Lavelle's Lecture Review Questions
Replies: 3
Views: 72

Re: Lavelle's Lecture Review Questions

I would assume it would be the same questions for each lecture.
by Daniel Toscano 1L
Sat Nov 30, 2019 8:40 am
Forum: General Science Questions
Topic: test taking nervousness
Replies: 19
Views: 313

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.
by Daniel Toscano 1L
Sat Nov 30, 2019 8:37 am
Forum: General Science Questions
Topic: test bank
Replies: 2
Views: 49

Re: test bank

There is a test bank at the CPO office in SAC.
by Daniel Toscano 1L
Sat Nov 30, 2019 8:36 am
Forum: General Science Questions
Topic: study tips for the final
Replies: 3
Views: 64

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.
by Daniel Toscano 1L
Sat Nov 30, 2019 8:32 am
Forum: Bronsted Acids & Bases
Topic: Bronsted Acid and base
Replies: 8
Views: 89

Re: Bronsted Acid and base

Bronstad acid and bases have to do with protons, while Lewis acids and bases have to do with electrons
by Daniel Toscano 1L
Thu Nov 28, 2019 7:56 pm
Forum: Naming
Topic: -ido vs -o
Replies: 5
Views: 58

Re: -ido vs -o

-ido and -o mean the same thing, it's just that -ido is now the "correct" version to use
by Daniel Toscano 1L
Tue Nov 26, 2019 8:00 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test #2 handback
Replies: 11
Views: 151

Re: Test #2 handback

If you have discussion this week, then this week. If not, then next week most likely.
by Daniel Toscano 1L
Tue Nov 26, 2019 6:56 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 7
Views: 101

Re: Test 2

The next time we see our TA's I believe
by Daniel Toscano 1L
Tue Nov 26, 2019 6:54 pm
Forum: Bronsted Acids & Bases
Topic: Definition
Replies: 5
Views: 71

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
by Daniel Toscano 1L
Tue Nov 26, 2019 5:11 pm
Forum: Administrative Questions and Class Announcements
Topic: Video Modules
Replies: 5
Views: 81

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
by Daniel Toscano 1L
Tue Nov 26, 2019 5:08 pm
Forum: Student Social/Study Group
Topic: Test 2 and Final
Replies: 18
Views: 226

Re: Test 2 and Final

My guess is that the TA's will give back test 2 next time we see them
by Daniel Toscano 1L
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: 55

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...
by Daniel Toscano 1L
Thu Nov 21, 2019 10:29 am
Forum: Lewis Structures
Topic: I3- Lewis Structure
Replies: 2
Views: 77

Re: I3- Lewis Structure

You always want to choose the most stable resonance structure, which in this case would be the first lewis structure.
by Daniel Toscano 1L
Thu Nov 21, 2019 10:26 am
Forum: Dipole Moments
Topic: Melting points
Replies: 15
Views: 392

Re: Melting points

I think only intermolecular forces affect melting/boiling points.
by Daniel Toscano 1L
Thu Nov 21, 2019 10:24 am
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Periodic Trends
Replies: 8
Views: 215

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
by Daniel Toscano 1L
Thu Nov 21, 2019 10:06 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Polarity and Number of Bonds
Replies: 3
Views: 77

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.
by Daniel Toscano 1L
Tue Nov 12, 2019 5:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 3
Views: 42

Re: Test 2

I think it'll be everything after the midterm up until this Friday.
by Daniel Toscano 1L
Tue Nov 12, 2019 5:39 pm
Forum: Octet Exceptions
Topic: expanded octet
Replies: 7
Views: 249

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.
by Daniel Toscano 1L
Tue Nov 12, 2019 5:34 pm
Forum: Resonance Structures
Topic: Writing Out Resonance
Replies: 3
Views: 56

Re: Writing Out Resonance

It'll be most safe to write out every resonance structure
by Daniel Toscano 1L
Tue Nov 12, 2019 5:33 pm
Forum: Properties of Light
Topic: Chemistry Community Posts
Replies: 10
Views: 328

Re: Chemistry Community Posts

Can confirm, 5 times a week
by Daniel Toscano 1L
Tue Nov 12, 2019 5:23 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 7
Views: 185

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)
by Daniel Toscano 1L
Mon Nov 04, 2019 7:36 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: "Polarizing power" in textbook
Replies: 2
Views: 54

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...
by Daniel Toscano 1L
Mon Nov 04, 2019 7:27 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Electron Configuration
Replies: 5
Views: 88

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).
by Daniel Toscano 1L
Thu Oct 31, 2019 11:38 am
Forum: DeBroglie Equation
Topic: Confused about equations
Replies: 7
Views: 102

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.
by Daniel Toscano 1L
Fri Oct 25, 2019 5:21 pm
Forum: Lewis Structures
Topic: Video Modules
Replies: 11
Views: 174

Re: Video Modules

I think the ones already posted are the only ones that are going to be posted.
by Daniel Toscano 1L
Fri Oct 18, 2019 2:47 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Exceptions
Replies: 4
Views: 62

Re: Exceptions

I think these 2 are the only ones we need to know for Chem 14A.
by Daniel Toscano 1L
Thu Oct 10, 2019 6:51 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Test Equation Sheets
Replies: 5
Views: 86

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.
by Daniel Toscano 1L
Thu Oct 10, 2019 6:34 pm
Forum: Empirical & Molecular Formulas
Topic: Mass Percent Calculations
Replies: 4
Views: 94

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.
by Daniel Toscano 1L
Thu Oct 10, 2019 6:28 pm
Forum: Student Social/Study Group
Topic: Pen or Pencil for Homework Problems?
Replies: 8
Views: 135

Re: Pen or Pencil for Homework Problems?

I'd assume It wouldn't matter whether you did the problems with pen or pencil.
by Daniel Toscano 1L
Sun Oct 06, 2019 4:14 pm
Forum: Balancing Chemical Reactions
Topic: Naming/Polyatomic ions
Replies: 4
Views: 64

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.

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