Search found 105 matches

by Lizette Noriega 1H
Wed Mar 11, 2020 5:21 pm
Forum: General Rate Laws
Topic: Rate Determining Step
Replies: 5
Views: 38

Rate Determining Step

Hi,
Is the rate-determining step the same as the slow step? Does this reaction ultimately define our rate?
by Lizette Noriega 1H
Wed Mar 11, 2020 5:18 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Pre-Equilibrium Approach
Replies: 2
Views: 33

Pre-Equilibrium Approach

Hello,

Can someone clarify the ideas behind the pre-equilibrium approach and explain when it is necessary to use this method? Thanks.
by Lizette Noriega 1H
Wed Mar 11, 2020 5:16 pm
Forum: General Rate Laws
Topic: Fast and Slow Step Reactions
Replies: 5
Views: 91

Fast and Slow Step Reactions

Hello,

What is the difference between a fast and slow step reaction? What does this information tell us with regard to solving problems?
by Lizette Noriega 1H
Wed Mar 11, 2020 5:14 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2
Replies: 3
Views: 57

Test 2

Hello,

Does anybody know if Test 2 will become available for pick up anytime soon?
by Lizette Noriega 1H
Wed Mar 11, 2020 12:55 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts vs. Intermediates
Replies: 8
Views: 71

Re: Catalysts vs. Intermediates

An intermediate is produced in the first step then later consumed in the second step while the catalyst is consumed in the first step then produced in the second.
by Lizette Noriega 1H
Tue Mar 03, 2020 5:40 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation
Replies: 3
Views: 83

Re: Nernst Equation

Letty Liu 2C wrote:I think it depends on what information you're given, so what you're working with. I believe there is only two versions of the Nernst equation though: one with lnQ and one with logQ.


Got it! But when do we use lnQ rather than logQ and vice versa?
by Lizette Noriega 1H
Tue Mar 03, 2020 5:39 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6N.15
Replies: 2
Views: 49

6N.15

I have a question about the following problem: Calculate the potential of a cell constructed with two nickel electrodes. The electrolyte in one compartment is 1.0 M Ni(NO3)2(aq). In the other compartment, NaOH has been added to a Ni(NO3)2 solution until the pH 5 11.0 at 298 K. See Table 6I.1. How do...
by Lizette Noriega 1H
Tue Mar 03, 2020 5:35 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Platinum and Granite
Replies: 4
Views: 44

Re: Platinum and Granite

Qiu Ya Wu 4I wrote:We use platinum and graphite as the electrode in our cell diagrams when there are no conducting solids present for the given half-reaction.


But what is the difference between the two? How do you know when to use one over the other?
by Lizette Noriega 1H
Tue Mar 03, 2020 5:02 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation
Replies: 3
Views: 83

Nernst Equation

I've seen the different versions of the Nernst equation but when do we know whether to apply one of the other?
by Lizette Noriega 1H
Tue Mar 03, 2020 5:01 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Platinum and Granite
Replies: 4
Views: 44

Platinum and Granite

When do we know to use Pt(s) or C(gr) as our solid in cell diagrams?
by Lizette Noriega 1H
Fri Feb 28, 2020 11:13 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Spontaneity
Replies: 12
Views: 268

Re: Spontaneity

positive cell potential (-E) = negative delta G = spontaneous
negative cell potential (+E) = positive delta G = nonspontaneous
by Lizette Noriega 1H
Fri Feb 28, 2020 11:11 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: platinum electrode
Replies: 2
Views: 30

Re: platinum electrode

The absence of a solid in your reaction would require the use of platinum as an electrode. As mentioned above, the fact that it is a good conductor will prevent it from interfering with the reaction.
by Lizette Noriega 1H
Fri Feb 28, 2020 11:07 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 19
Views: 197

Test 2

Will Test 2 have any overlapping topics from the midterm? Or will it only cover topics from the midterm up until now?
by Lizette Noriega 1H
Fri Feb 28, 2020 11:06 pm
Forum: Balancing Redox Reactions
Topic: Cell Diagrams
Replies: 14
Views: 123

Cell Diagrams

Does it matter which side you place the reduced reaction and the oxidized reaction? I've come across multiple sources that switch the orientation of the anode and cathodes so I could use some clarification on that. Thanks!
by Lizette Noriega 1H
Fri Feb 28, 2020 10:07 pm
Forum: Balancing Redox Reactions
Topic: Acidic and Basic solutions
Replies: 11
Views: 98

Re: Acidic and Basic solutions

The procedure is the same but the basic solution requires you to use OH- instead of H+
by Lizette Noriega 1H
Sun Feb 23, 2020 10:38 am
Forum: Balancing Redox Reactions
Topic: Cell Diagrams
Replies: 6
Views: 88

Re: Cell Diagrams

My TA was informing us that the standard order for the elements in the cell diagram goes as following: solid|gas|aqueous || aqueous|gas|solid But it would be difficult to establish their phase accordingly. The question should provide you with any information you need while keeping in mind that one l...
by Lizette Noriega 1H
Sun Feb 23, 2020 12:38 am
Forum: General Science Questions
Topic: Content on Test 2
Replies: 10
Views: 120

Re: Content on Test 2

According to Lavelle's website, Test 2 will cover the 2nd page of Thermodynamics (see Outline) and Electrochemistry
by Lizette Noriega 1H
Sun Feb 23, 2020 12:24 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Using Pt
Replies: 7
Views: 96

Re: Using Pt

You can use Pt (s) if there is an absence of a solid in a redox reaction; because it is an inert conductor, it will allow for the transfer of electrons without interfering with the reaction itself
by Lizette Noriega 1H
Sun Feb 23, 2020 12:19 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Determining if a cell reaction is spontaneuous
Replies: 5
Views: 45

Re: Determining if a cell reaction is spontaneuous

A positive cell potential (E) will result in a negative delta G (via the equation delta G = -nFE), thus creating a spontaneous reaction. Similarly, a negative cell potential will result in a positive delta G, creating a nonspontaneous reaction
by Lizette Noriega 1H
Sun Feb 23, 2020 12:08 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 1
Views: 31

Salt Bridge

Hello,
I just need clarification on the function of the salt bridge. Is its purpose to neutralize the charge build-up within the galvanic cell?
by Lizette Noriega 1H
Thu Feb 13, 2020 12:00 pm
Forum: General Science Questions
Topic: 50 post grade
Replies: 25
Views: 801

Re: 50 post grade

It's entirely up to the TA- some will require you to submit 5 posts per week while others are fine with a total of 50 posts by the end of the quarter
by Lizette Noriega 1H
Thu Feb 13, 2020 11:56 am
Forum: Student Social/Study Group
Topic: Midterm
Replies: 8
Views: 339

Re: Midterm

My TA told us that 4I.9 was the homework question used on that exam
by Lizette Noriega 1H
Thu Feb 13, 2020 9:28 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Significance of open, closed, isolated
Replies: 11
Views: 260

Re: Significance of open, closed, isolated

The status of the system helps you recognize the presence/absence of exchange in energy and matter, thus allowing you to understand the relationship between the system and its surroundings (and helps you solve the problems given).
by Lizette Noriega 1H
Thu Feb 13, 2020 9:26 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: units for heat capacity
Replies: 2
Views: 116

Re: units for heat capacity

As mentioned above, the units for heat capacity should be Joules/Celcius (J/°C) but if given kilojoules (kJ), this should be an acceptable answer as well unless the question specifically asks for joules, in which you would have to convert from kilojoules to joules.
by Lizette Noriega 1H
Thu Feb 13, 2020 9:23 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: change in Kc
Replies: 5
Views: 73

Re: change in Kc

If you were to reverse a reaction, the value for the constant will be the inverse (1/Kc) whereas if you multiply the reaction by some constant, the value of Kc will have to be raised by the same value (Kc^x).
by Lizette Noriega 1H
Fri Feb 07, 2020 4:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 1 Distribution
Replies: 9
Views: 136

Re: Test 1 Distribution

As everyone else has mentioned, there is no score distribution but you should ask your TA about your class average.
by Lizette Noriega 1H
Fri Feb 07, 2020 4:14 pm
Forum: Student Social/Study Group
Topic: Any Worksheets from UA/TA/etc?
Replies: 14
Views: 285

Re: Any Worksheets from UA/TA/etc?

You can check out Lyndon's review worksheet which will be posted tonight around 7 pm. He will be hosting a review session to go over the problems on Sunday.
by Lizette Noriega 1H
Fri Feb 07, 2020 4:13 pm
Forum: General Science Questions
Topic: Midterms
Replies: 22
Views: 337

Re: Midterms

Yes, the midterm will be cumulative, covering the topics from equilibrium to thermodynamics
by Lizette Noriega 1H
Fri Feb 07, 2020 3:55 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: biological examples
Replies: 7
Views: 112

Re: biological examples

Are these biological examples going to be on the midterm?
by Lizette Noriega 1H
Fri Feb 07, 2020 3:46 pm
Forum: Calculating Work of Expansion
Topic: Isothermal
Replies: 17
Views: 164

Re: Isothermal

Isothermal means there is a constant temperature present in the system, therefore, the most ideal equations to use would be the ones that include a change in volume or pressure
by Lizette Noriega 1H
Fri Jan 31, 2020 2:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Math Resources
Replies: 8
Views: 84

Math Resources

Hello,

In today's lecture, Lavelle mentioned having extra resources to review on calculus. Can these be found on his website?

Thanks!
by Lizette Noriega 1H
Fri Jan 31, 2020 2:01 pm
Forum: General Science Questions
Topic: Extra Credit
Replies: 19
Views: 263

Re: Extra Credit

Unfortunately, there are no extra credit opportunities for this class. Make sure to try your best and study hard!
by Lizette Noriega 1H
Fri Jan 31, 2020 1:58 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: State Functions
Replies: 6
Views: 63

Re: State Functions

Unlike heat and work functions, they are dependent on the path taken in order to reach the endpoint
by Lizette Noriega 1H
Fri Jan 31, 2020 1:54 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: hess's law
Replies: 13
Views: 87

Re: hess's law

Yes, they must be on opposite sides and they have to be balanced in order to cancel them out
by Lizette Noriega 1H
Fri Jan 31, 2020 1:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm
Replies: 8
Views: 118

Re: Midterm

Based off of Lavelle's class announcements, I believe it will cover all the topics we have discussed until now, finishing with thermodynamics. You can use the class outlines to guide your studying as Lavelle has mentioned that the material is based on the objectives
by Lizette Noriega 1H
Fri Jan 24, 2020 5:15 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem 14A Final Exam
Replies: 1
Views: 51

Chem 14A Final Exam

Does anyone know if the final exams are available after Week 3? If so, where can we find them?
by Lizette Noriega 1H
Thu Jan 23, 2020 10:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Best Way To Study?
Replies: 13
Views: 145

Re: Best Way To Study?

I would definitely recommend the UA sessions. For extra practice and better understanding, I would recommend "The Organic Chemistry Tutor" on Youtube because he explains concepts in addition to working through examples. Overall, try to stay on track with the homework and understand them as...
by Lizette Noriega 1H
Thu Jan 23, 2020 9:55 pm
Forum: Phase Changes & Related Calculations
Topic: Autoprotolysis
Replies: 15
Views: 144

Re: Autoprotolysis

It is the proton transfer between two of the same molecules
by Lizette Noriega 1H
Tue Jan 21, 2020 8:22 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Practice Worksheet for Test 1
Replies: 1
Views: 82

Practice Worksheet for Test 1

Can anyone explain how they solved the following question (#7 from the UA Practice Exam Worksheet)? Thanks!

"A basic aqueous reaction initially had 0.057 M NH3. At equilibrium the concentration of hydroxides was 1.0x10^-3. Write out the equation and find the percent protonated."
by Lizette Noriega 1H
Tue Jan 21, 2020 8:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Worksheet Practice for Test 1
Replies: 3
Views: 105

Re: Worksheet Practice for Test 1

You would set up an ice table. Initial concentrations: 1 for H2, 2 for Cl2, and 0 for HCl. We don't know how much the change is, so we represent this with -x, -x, and +2x, respectively. Therefore, the expressions for the equilibrium are: H2 = 1-x, Cl2 = 2-x, and HCl = 4x^2. Write the expression for...
by Lizette Noriega 1H
Tue Jan 21, 2020 8:10 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 1 Study Guide/Worksheet
Replies: 5
Views: 647

Re: Test 1 Study Guide/Worksheet

Can someone explain their process for #6? Thanks!
by Lizette Noriega 1H
Wed Jan 15, 2020 9:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When to use K and Kp
Replies: 12
Views: 80

Re: When to use K and Kp

If the problem doesn't specify, either should be fine to use. Although, if you are given concentrations then you are likely to use Kc rather than Kp, or if the problem mentions a gas, you would use Kp for partial pressure
by Lizette Noriega 1H
Wed Jan 15, 2020 9:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Study Guide Test One
Replies: 17
Views: 194

Re: Study Guide Test One

I don't believe so but it's useful to rely on the learning outcomes and base your studying on the areas you need the most practice on
by Lizette Noriega 1H
Wed Jan 15, 2020 9:15 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Factors
Replies: 7
Views: 61

Factors

Is temperature the only factor that influences K? Also, which factors influence the reaction quotient?
by Lizette Noriega 1H
Wed Jan 15, 2020 9:12 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: biological examples
Replies: 2
Views: 57

Re: biological examples

Just curious, do you know if we'll need to know certain biological examples for future exams?
by Lizette Noriega 1H
Wed Jan 15, 2020 9:05 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE Tables
Replies: 4
Views: 54

ICE Tables

I'm still a bit confused when it comes to ICE tables. What are certain indicators of a problem that lets us know we'll need an ICE table to solve it?
by Lizette Noriega 1H
Thu Jan 09, 2020 9:17 pm
Forum: Student Social/Study Group
Topic: Homework for Week 1
Replies: 6
Views: 78

Homework for Week 1

Is the homework for this week due tomorrow (Friday) in lecture or in discussion next week?
by Lizette Noriega 1H
Thu Jan 09, 2020 9:13 pm
Forum: Ideal Gases
Topic: R in PV=nRT
Replies: 34
Views: 662

Re: R in PV=nRT

R is the gas constant but it can use different units such as torr, atm, or bar
by Lizette Noriega 1H
Thu Jan 09, 2020 8:54 pm
Forum: Ideal Gases
Topic: converting Kc to Kp
Replies: 13
Views: 136

Re: converting Kc to Kp

Megan Kirschner wrote:What exactly is the difference between Kc and Kp? I know (or think) they are equilibria constants but what do they individually represent?


Kc is used for the concentration of aqueous solutions and gases while Kp is for the partial pressures of gases
by Lizette Noriega 1H
Thu Jan 09, 2020 8:41 pm
Forum: Ideal Gases
Topic: Reaction Quotient (Q)
Replies: 8
Views: 87

Reaction Quotient (Q)

Can someone explain the concept behind Q? When is it essential?
by Lizette Noriega 1H
Thu Jan 09, 2020 8:18 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc and Kp
Replies: 4
Views: 42

Kc and Kp

Can someone clarify the following for me? Are these the correct uses for Kc and Kp?

Kc = concentration of gases
Kp = partial pressures
by Lizette Noriega 1H
Thu Jan 09, 2020 8:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Units for K
Replies: 10
Views: 84

Units for K

Why doesn't K have any units?
by Lizette Noriega 1H
Fri Dec 06, 2019 1:12 am
Forum: Calculating the pH of Salt Solutions
Topic: Wednesday Lecture 12/4
Replies: 4
Views: 76

Re: Wednesday Lecture 12/4

Wednesday's lecture placed emphasis on Chem 14B and introduced us to the topics we will learn in that class. I don't believe we have to know anything in particular from that lecture for the final
by Lizette Noriega 1H
Fri Dec 06, 2019 1:10 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Shape
Replies: 1
Views: 42

Shape

How would you figure out the shape of the following coordinate compound?

[Cr(NH3)3Cl3]
by Lizette Noriega 1H
Thu Dec 05, 2019 3:06 pm
Forum: Biological Examples
Topic: Biological questions on the final
Replies: 5
Views: 135

Re: Biological questions on the final

I would suggest looking at the examples mentioned above plus acid rain (not for coordination compounds but it is a real-life example that has come up throughout UA worksheets)
by Lizette Noriega 1H
Thu Dec 05, 2019 3:03 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: -ate
Replies: 11
Views: 253

Re: -ate

-ate is added to the end of the metal name when there is an overall negative charge to the complex
by Lizette Noriega 1H
Thu Dec 05, 2019 2:59 pm
Forum: Student Social/Study Group
Topic: Finals Preparation
Replies: 7
Views: 142

Re: Finals Preparation

Avoiding any last-minute cramming and getting a good night's sleep is always a good idea before exams
by Lizette Noriega 1H
Thu Dec 05, 2019 2:57 pm
Forum: Student Social/Study Group
Topic: Grading
Replies: 3
Views: 115

Grading

The syllabus states, "50% or higher is required to pass with a C- or higher". Does this mean you need 250 out of the 500 points to pass the class with a C-?
by Lizette Noriega 1H
Tue Nov 26, 2019 11:30 am
Forum: Bronsted Acids & Bases
Topic: Lewis Structures of Acid/Base reactions
Replies: 3
Views: 44

Re: Lewis Structures of Acid/Base reactions

I don't believe it will be on the test but Dr.Lavelle draws the structures in class in order to help us better understand the concept. Drawing the Lewis structures can only benefit you but it is not required
by Lizette Noriega 1H
Tue Nov 26, 2019 11:26 am
Forum: Sigma & Pi Bonds
Topic: Molecular Shape
Replies: 11
Views: 126

Re: Molecular Shape

They do not influence molecular structure because each bond is considered to be one region of electron density, despite the single/double/triple bonds that can be present
by Lizette Noriega 1H
Tue Nov 26, 2019 11:23 am
Forum: Naming
Topic: -ate ending
Replies: 8
Views: 97

Re: -ate ending

If the complex is an anion/contains a negative charge, you at the -ate to the end of the transition metal
by Lizette Noriega 1H
Tue Nov 26, 2019 11:19 am
Forum: Naming
Topic: H2O vs OH2
Replies: 3
Views: 52

Re: H2O vs OH2

They are interchangeable terms but using one over the other is to indicate the presence of the lone pair on the oxygen. Usually, H2O is written on the left and OH2 is on the right in order to accommodate for the bond that exists between the lone pair of the oxygen and the ligand/central atom
by Lizette Noriega 1H
Tue Nov 26, 2019 11:15 am
Forum: Dipole Moments
Topic: Intermolecular force
Replies: 5
Views: 377

Re: Intermolecular force

Yes, that should be fine because it is true that the stronger an intermolecular force is, the more difficult it is to break the bond
by Lizette Noriega 1H
Sun Nov 24, 2019 11:04 pm
Forum: Student Social/Study Group
Topic: Any tips on how to catch up in this class?
Replies: 16
Views: 255

Re: Any tips on how to catch up in this class?

I'd recommend studying with others, attending the UA workshops, and watching YouTube videos that cover the general ideas on the topics we are studying. It is pretty easy to get lost in the class but reserving time to review past material is essential for catching up in addition to making use of thes...
by Lizette Noriega 1H
Sat Nov 23, 2019 4:32 pm
Forum: Hybridization
Topic: Sigma and Pi Bonds
Replies: 6
Views: 96

Re: Sigma and Pi Bonds

If the orbitals that form sigma bonds overlap more than the pi bonds, how is it that sigma bonds can rotate and have more flexibility than the pi bonds?
by Lizette Noriega 1H
Sat Nov 23, 2019 4:29 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanksgiving Break
Replies: 4
Views: 92

Re: Thanksgiving Break

Lavelle has a post on Chemistry Community (see link below) where he states that we can turn in the homework for Week 9 and 10 during Week 10

viewtopic.php?f=157&t=52609
by Lizette Noriega 1H
Sat Nov 23, 2019 4:26 pm
Forum: General Science Questions
Topic: Final
Replies: 10
Views: 198

Re: Final

The final is cumulative so it will be covering all the topics from weeks 1-10
by Lizette Noriega 1H
Sat Nov 23, 2019 4:25 pm
Forum: Administrative Questions and Class Announcements
Topic: Lecture on 11/27
Replies: 4
Views: 67

Lecture on 11/27

Will we still have lecture on Wednesday, November 27th or will it be canceled due to Thanksgiving break? Thanks
by Lizette Noriega 1H
Sun Nov 17, 2019 2:15 pm
Forum: Hybridization
Topic: Test?
Replies: 6
Views: 71

Re: Test?

Lavelle said during Friday's lecture that hybridization will not be included on the test. The cutoff will be at sigma bonds which will be the first slide on Monday's lecture
by Lizette Noriega 1H
Sun Nov 17, 2019 1:28 pm
Forum: General Science Questions
Topic: Test 2
Replies: 7
Views: 80

Re: Test 2

The test will cover material after the midterm which has been very conceptual thus far. I don't think certain calculations are required but I would suggest checking in with the TAs
by Lizette Noriega 1H
Sun Nov 17, 2019 1:23 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 Points
Replies: 7
Views: 80

Boiling Points

What is the relationship between boiling points and the type of intermolecular force? Are boiling points dependent on the strength of the force? Thanks!
by Lizette Noriega 1H
Sun Nov 17, 2019 1:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Interactions
Replies: 3
Views: 38

Interactions

Out of the following interactions, is this the correct order from strongest to weakest bond?

ion-dipole > hydrogen bonds > dipole-dipole > Van Der Waals

Also, is Van Der Waals the same as London Dispersing forces? If not, what is their difference? Thanks!
by Lizette Noriega 1H
Sun Nov 17, 2019 12:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Wed before Thanksgiving
Replies: 3
Views: 59

Re: Wed before Thanksgiving

As far as everyone knows, we will have a lecture on Wednesday before Thanksgiving. You can always double-check with the TAs or with Lavelle beforehand though
by Lizette Noriega 1H
Thu Nov 07, 2019 10:10 pm
Forum: Bond Lengths & Energies
Topic: Week 7 Homework
Replies: 15
Views: 226

Week 7 Homework

For next week's homework are we turning in questions from the Chemical Bonds section or do we move onto Molecular Shape and Structure?
by Lizette Noriega 1H
Thu Nov 07, 2019 1:21 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Shortcut for Formal Charge
Replies: 14
Views: 482

Re: Shortcut for Formal Charge

(# of valence electrons) - (# of electrons + # of bonds) = formal charge

or if you want an even simpler way of thinking about it: (# of valence electrons) - (# of dots + # of lines)
by Lizette Noriega 1H
Thu Nov 07, 2019 1:18 pm
Forum: Lewis Structures
Topic: When to draw Resonance Structures
Replies: 14
Views: 173

Re: When to draw Resonance Structures

It's best to always draw resonance structures if the molecule has them. It demonstrates your understanding and it's just safe to have even if you aren't being directly asked to provide them
by Lizette Noriega 1H
Thu Nov 07, 2019 1:17 pm
Forum: Ionic & Covalent Bonds
Topic: Solubility
Replies: 3
Views: 55

Solubility

How do solubility and ionic/covalent character relate to one another? Is ionic character more soluble and covalent character less soluble?
by Lizette Noriega 1H
Thu Nov 07, 2019 1:14 pm
Forum: Student Social/Study Group
Topic: Class Grading
Replies: 44
Views: 2057

Re: Class Grading

Yes, that's correct. The grades will be dependent on the number of points and the cutoffs made by Dr.Lavelle with regards to the class average
by Lizette Noriega 1H
Thu Nov 07, 2019 1:10 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths in resonance structures
Replies: 2
Views: 33

Re: Bond lengths in resonance structures

The bond lengths in resonance structures will be an average of all the present bonds; this is due to the creation of a resonance hybrid which creates another molecular structure from all the other existing resonance structures
by Lizette Noriega 1H
Thu Oct 31, 2019 11:39 am
Forum: Administrative Questions and Class Announcements
Topic: Study Tips!
Replies: 7
Views: 105

Re: Study Tips!

Watching YouTube videos and taking notes on them has been very resourceful for me. It helps me gain a better understanding of the concepts for equations and the main topics of our classes.
by Lizette Noriega 1H
Thu Oct 31, 2019 11:33 am
Forum: Photoelectric Effect
Topic: Threshold Energy
Replies: 5
Views: 95

Threshold Energy

Hello, I just need clarification on threshold energy. I know the threshold energy is the energy needed in order to eject electrons from a metal surface but in terms of the equation, is it represented by the work function? Thanks!
by Lizette Noriega 1H
Thu Oct 31, 2019 11:24 am
Forum: DeBroglie Equation
Topic: Confused about equations
Replies: 7
Views: 102

Confused about equations

Hello,

This is a dumb question but I need clarification as to when you use certain equations since I always seem to mix them up. For instance, what kinds of problems indicate the use of the de Broglie equation (λ = h/mv) in contrast to the equations for wavelength (c= λv) and energy (E=hv)?

Thanks!
by Lizette Noriega 1H
Thu Oct 31, 2019 11:14 am
Forum: Student Social/Study Group
Topic: Study Tips
Replies: 58
Views: 2105

Re: Study Tips

Personally I have found YouTube to be very resourceful because the videos provide extra material in addition to lectures which helps me understand the concepts better and relate them to the practice problems we go over. I would also suggest taking notes while you're watching the video because it's h...
by Lizette Noriega 1H
Thu Oct 31, 2019 11:06 am
Forum: Molarity, Solutions, Dilutions
Topic: Practice Question for Midterm
Replies: 2
Views: 178

Re: Practice Question for Midterm

Thank you so much!! That makes more sense. The equation editor is really useful in making sense of the math so thanks for that as well.
by Lizette Noriega 1H
Wed Oct 30, 2019 1:58 pm
Forum: Molarity, Solutions, Dilutions
Topic: Practice Question for Midterm
Replies: 2
Views: 178

Practice Question for Midterm

Hello, could someone explain how to solve for this question? Thanks! "Potassium permanganate, KMnO4, is an inorganic chemical compound used for cleaning wounds. 5.00 g of KMnO4 is dissolved in a 150.00 mL flask of water. If 20.00 mL of this solution is removed and placed in a new 2nd 250.00 mL ...
by Lizette Noriega 1H
Thu Oct 24, 2019 5:26 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Noble Gas Configuration
Replies: 10
Views: 126

Re: Noble Gas Configuration

There's no specific rule as to when you must use the noble gas configuration over the complete electron configuration. My TA said it is much simpler to use the noble gas configuration but to be careful on exams when you are asked to provide the entire electron configuration of an element
by Lizette Noriega 1H
Thu Oct 24, 2019 5:18 pm
Forum: Trends in The Periodic Table
Topic: Periodic Trend Exceptions
Replies: 7
Views: 78

Re: Periodic Trend Exceptions

I know there is a trend for valence electrons which is to look at the column number to determine the number of valence electrons found in a certain element. Although, this only applies to the s and p blocks.
by Lizette Noriega 1H
Thu Oct 24, 2019 5:03 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg equation [ENDORSED]
Replies: 73
Views: 3705

Re: Rydberg equation [ENDORSED]

In what kinds of scenarios or questions would we need to use the Rydberg equation?
by Lizette Noriega 1H
Thu Oct 24, 2019 12:41 pm
Forum: Ionic & Covalent Bonds
Topic: Cation
Replies: 23
Views: 456

Re: Cation

Cations are atoms with a positive charge (+) while anions are atoms with a negative charge (-); this is due to the loss or gain of electrons. They are important because they are essential to the formation of ionic bonds, bonds in which electrons are lost or gained in order to reach a more stable sta...
by Lizette Noriega 1H
Thu Oct 24, 2019 11:00 am
Forum: Properties of Light
Topic: Midterm
Replies: 4
Views: 101

Re: Midterm

He did mention that he will have multiple review sessions (spread out through his lectures I believe?) but primarily, he mentioned having a large review session on the Saturday or Sunday before the midterm- his only concern is obtaining a large lecture room so that many people can attend. He also me...
by Lizette Noriega 1H
Wed Oct 16, 2019 4:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Tutoring? [ENDORSED]
Replies: 69
Views: 72155

Re: Tutoring? [ENDORSED]

I would definitely recommend signing up for AAP's peer learning sessions as well as joining study groups with other classmates. There are many resources out there in addition to tutors. Peer learning sessions offer many study sessions so they are flexible with your schedules- they also do midterm an...
by Lizette Noriega 1H
Wed Oct 16, 2019 4:21 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Difference Between Ground and Excited States
Replies: 3
Views: 50

Re: Difference Between Ground and Excited States

An electron is at its excited state whenever its energy level is higher than its corresponding ground state. During ground state, its electron configuration is at default whereas, during the excited state, it will jump into a high orbital
by Lizette Noriega 1H
Wed Oct 16, 2019 4:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 2 Homework Problems [ENDORSED]
Replies: 67
Views: 3450

Re: Week 2 Homework Problems [ENDORSED]

RichBollini3C wrote:
Diana Chavez-Carrillo 3J wrote:Are the TA's grading our homework based on completion or correctness?

I believe they are grading based on correctness.


Do you know if all the TAs grade based on correctness or does it vary from TA to TA?
by Lizette Noriega 1H
Wed Oct 16, 2019 4:13 pm
Forum: *Shrodinger Equation
Topic: Equations for Quantum Topics
Replies: 3
Views: 50

Equations for Quantum Topics

Hello, I'm just looking for clarification on the equations that are currently being used in the material we are studying right now. So far, Lavelle has gone over three main equations: the de Broglie equation, Schrodinger's equation, and Heisenberg's indeterminacy equation. Are there any more essenti...
by Lizette Noriega 1H
Wed Oct 16, 2019 4:06 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What are subshells
Replies: 4
Views: 66

Re: What are subshells

The letter, s, p, d, and f, refer to subshells which are orbitals that correspond to already existing orbitals. Each of the subshells has its own orbitals as well. For example, the s subshell has 1, the p subshell has 3, and so forth.
by Lizette Noriega 1H
Fri Oct 11, 2019 11:28 am
Forum: Student Social/Study Group
Topic: Peer Learning Sessions
Replies: 3
Views: 73

Re: Peer Learning Sessions

Anyone enrolled in the course can attend- you just show up to the session!
by Lizette Noriega 1H
Fri Oct 11, 2019 11:26 am
Forum: Student Social/Study Group
Topic: Weekly Posts
Replies: 6
Views: 118

Weekly Posts

Hello- are our five weekly posts due by Friday or Sunday? I know we have to post five comments by the end of the week but I was wondering if there was a definite deadline. Thanks!
by Lizette Noriega 1H
Fri Oct 11, 2019 11:11 am
Forum: Administrative Questions and Class Announcements
Topic: Weekly Posts
Replies: 4
Views: 76

Re: Weekly Posts

I don't believe any comments from the previous week carries onto the next- this is to encourage students to interact weekly. I would suggest making five posts per week just to be safe.
by Lizette Noriega 1H
Fri Oct 11, 2019 11:08 am
Forum: Administrative Questions and Class Announcements
Topic: Posting
Replies: 3
Views: 53

Re: Posting

You can go to the board index and scroll down until you find the forums. From there, you open the forum that corresponding to the topic of your choosing. After you've opened it, you can click on "New Topic" in order to make a post. Hope this helps!
by Lizette Noriega 1H
Fri Oct 11, 2019 11:00 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Theoretical vs. Actual Yield
Replies: 38
Views: 3385

Re: Theoretical vs. Actual Yield

Like any experiment, there are always side reactions that can occur such as loss of heat, impurities (product sticks to the side of the beaker), or human error (incorrect measurements of reactants). Taking these things into account, the actual yield is going to be less than the theoretical yield bec...

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