Search found 100 matches

by 805291863
Sat Mar 14, 2020 8:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem Community Posts Due Date
Replies: 13
Views: 363

Re: Chem Community Posts Due Date

Last post for me!
by 805291863
Sat Mar 14, 2020 8:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanks From the UA’s!
Replies: 5
Views: 288

Re: Thanks From the UA’s!

Thank you for all that you've done! You've truly made chemistry more enjoyable!
by 805291863
Sat Mar 14, 2020 8:17 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading Scale
Replies: 14
Views: 331

Re: Grading Scale

As others have mentioned, the pass cutoff is the same and grades will be assigned based on performance. The average midterm grade was quite similar to last quarter's, so I'd assume it will be pretty similar despite the very different final we will take
by 805291863
Sat Mar 14, 2020 8:15 pm
Forum: Administrative Questions and Class Announcements
Topic: Final- general questions
Replies: 12
Views: 231

Re: Final- general questions

Will the answer format be multiple choice or fill in the blank?
by 805291863
Wed Mar 11, 2020 12:19 pm
Forum: General Science Questions
Topic: Review Packet
Replies: 14
Views: 322

Re: Review Packet

Subashni Rajiv 1K wrote:Lyndon just posted practice problems for Electrochemistry and Kinetics that can be found if you search up ENDGAME.


Thank you!
by 805291863
Sat Mar 07, 2020 1:22 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Proposing Reaction Mechanisms
Replies: 3
Views: 51

Re: Proposing Reaction Mechanisms

Okay, thank you so much!
by 805291863
Sat Mar 07, 2020 1:21 pm
Forum: General Rate Laws
Topic: conceptual question (zero order)
Replies: 3
Views: 58

Re: conceptual question (zero order)

For a conceptual explanation for zero order reactions, this is what I found online: "There are two general conditions that can give rise to zero-order rates: 1. Only a small fraction of the reactant molecules are in a location or state in which they are able to react, and this fraction is conti...
by 805291863
Sat Mar 07, 2020 1:18 pm
Forum: General Rate Laws
Topic: Rate laws
Replies: 4
Views: 112

Re: Rate laws

The coefficient does not automatically translate to the exponent in the rate law. As for how to determine the rate law, it is always based on experimental data
by 805291863
Sat Mar 07, 2020 1:14 pm
Forum: Experimental Details
Topic: determining order of reaction
Replies: 6
Views: 153

Re: determining order of reaction

I believe we will not always be given the order of the reaction, but you can tell by looking at graphs of ln[A] vs time, 1/[A] vs time, and [A] vs time. The graph that is a linear line indicates the order of that reaction
by 805291863
Sat Mar 07, 2020 1:11 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Proposing Reaction Mechanisms
Replies: 3
Views: 51

Proposing Reaction Mechanisms

Would we ever be asked to propose a reaction mechanism?
by 805291863
Sun Mar 01, 2020 3:10 pm
Forum: Zero Order Reactions
Topic: Deriving Equations
Replies: 7
Views: 638

Re: Deriving Equations

Here is a link to the constants and equations page that we will be given on exams. Hope this helps!

https://lavelle.chem.ucla.edu/wp-content/supporting-files/Chem14B/Constants_Equations.pdf
by 805291863
Sun Mar 01, 2020 3:09 pm
Forum: General Rate Laws
Topic: rate law
Replies: 2
Views: 50

Re: rate law

I think that using both reactants and products factors in the rate of the reverse reaction occurring at the same time as the forward reaction. For this class, I believe we are generally focused on just the reactants because that defines the initial reaction rate
by 805291863
Sun Mar 01, 2020 3:04 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Partial Pressures in Q
Replies: 2
Views: 52

Re: Partial Pressures in Q

They can be in any unit as long as you make sure you use the corresponding R value
by 805291863
Sun Mar 01, 2020 3:02 pm
Forum: General Science Questions
Topic: Studying
Replies: 19
Views: 312

Re: Studying

I read over my notes after each lecture, do all the homework problems, and attend review sessions. Having access to past exam questions is also incredibly useful!
by 805291863
Sun Mar 01, 2020 2:59 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: intermediate
Replies: 22
Views: 727

Re: intermediate

Intermediates are easily recognizable in a reaction mechanism, which is the sequence of elementary reactions to go from reactants to products. The molecules that are formed and consumed in these elementary reactions are intermediates
by 805291863
Sat Feb 22, 2020 10:57 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Hg
Replies: 2
Views: 33

Re: Hg

Also, they have different standard potentials, so be careful when doing calculations!
by 805291863
Sat Feb 22, 2020 10:55 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Concentration
Replies: 2
Views: 46

Re: Concentration

The affect of concentration on cell potential can be seen through the Nerst Equation, which includes Q. The reaction quotient is determined by the concentrations of the products and reactants, so concentrations will affect the cell potential
by 805291863
Sat Feb 22, 2020 10:51 pm
Forum: Student Social/Study Group
Topic: Curve?
Replies: 42
Views: 1614

Re: Curve?

Especially considering that the class average for this midterm was a bit higher than last quarter's, I think it is currently highly unlikely for a significant curve
by 805291863
Sat Feb 22, 2020 10:47 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: electrochemical series
Replies: 4
Views: 76

Re: electrochemical series

It is the table that lists reductions and its potentials. To find the potential for an oxidation, you flip the sign of the potential on the electrochemical series
by 805291863
Sat Feb 22, 2020 10:13 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.3
Replies: 6
Views: 125

Re: 6N.3

Also, how is the n value determined here?
by 805291863
Sat Feb 15, 2020 7:42 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8226
Views: 1435593

Re: Post All Chemistry Jokes Here

Image
by 805291863
Sat Feb 15, 2020 7:37 pm
Forum: Student Social/Study Group
Topic: Preparing for Exam Content
Replies: 7
Views: 191

Preparing for Exam Content

To be honest, some of the questions on the midterm were not what I expected in terms of the types of questions and way you were to answer them. I did all the homework questions, went to review sessions, and paid attention in class. Did anyone else also feel this way? Does anyone have advice on how t...
by 805291863
Sat Feb 15, 2020 7:33 pm
Forum: Student Social/Study Group
Topic: Curve?
Replies: 42
Views: 1614

Re: Curve?

If I remember currently from the beginning of last quarter, Dr. Lavelle mentioned that there is the possibility of a curve at the end of the quarter if the grade distribution deems it necessary. Also, if there were to be a curve, it would only help your grade, not hurt it.
by 805291863
Sat Feb 15, 2020 7:31 pm
Forum: Student Social/Study Group
Topic: Number of Chemistry Community Posts
Replies: 33
Views: 782

Re: Number of Chemistry Community Posts

Maya Beal Dis 1D wrote:When are the posts due every week? Is it Friday or Sunday?


Posts are due every Sunday
by 805291863
Sat Feb 15, 2020 7:27 pm
Forum: Balancing Redox Reactions
Topic: redox reactions
Replies: 3
Views: 67

Re: redox reactions

In particular, redox reactions hold a great importance in biological systems. Cellular respiration, for example, greatly relies on redox reactions in order to efficiently and usefully harvest energy from glucose.
by 805291863
Sat Feb 08, 2020 10:04 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Error in Boltzmann Equation
Replies: 4
Views: 60

Re: Error in Boltzmann Equation

This means that an error in W will have a small effect on S, helping S be a more accurate measurement of entropy
by 805291863
Sat Feb 08, 2020 10:02 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Units
Replies: 4
Views: 60

Units

What is the units for change in entropy? When you take the ln of V2/V1 or T2/T2, does the unit of the volume or temperature remain?
by 805291863
Sat Feb 08, 2020 9:59 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Predicting Entropy
Replies: 2
Views: 55

Re: Predicting Entropy

Entropy depends on the number of molecules and the number of states the molecules can be in. Therefore, the greater the number of molecules, the greater the amount of entropy. Also, the more complex the molecule, the greater the amount of entropy
by 805291863
Sat Feb 08, 2020 9:57 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Types of reaction & Equations
Replies: 3
Views: 50

Types of reaction & Equations

Could someone please summarize which equations (relating to delta U, q, w, and delta S) should be used for which type of reaction? I've been a bit confused and some clarification would really help!
by 805291863
Sat Feb 08, 2020 5:31 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Delta U in an Open System
Replies: 1
Views: 34

Delta U in an Open System

How do you calculate delta U in an open system?

I'm especially confused on how to calculate work if the reactants and products are gases and the system is open. How do you know if there is a change in volume? Do you compare the sum of the coefficients of the products and of the reactants?
by 805291863
Sat Feb 01, 2020 2:21 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4C.11 and 4C.13
Replies: 1
Views: 30

Re: 4C.11 and 4C.13

I was wondering the same thing! Should we never use the specific heat unless the problem uses a calorimeter?
by 805291863
Sat Feb 01, 2020 2:17 pm
Forum: Calculating Work of Expansion
Topic: The integral of pressure and the derivative of volume equation
Replies: 1
Views: 28

Re: The integral of pressure and the derivative of volume equation

Yes, the equation of work as an integral applies only to reversible processes in which the system is at equilibrium
by 805291863
Sat Feb 01, 2020 2:15 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: reversible and irreversible processes
Replies: 9
Views: 489

Re: reversible and irreversible processes

How will we be able to differentiate between a reversible and irreversible process on an exam? Will it be given to us or do we have to make the distinction?
by 805291863
Sat Feb 01, 2020 2:12 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated systems
Replies: 4
Views: 53

Re: Isolated systems

For the purposes of this class, I'm pretty sure we are supposed to assume that insulated calorimeters are an isolated system
by 805291863
Sat Feb 01, 2020 2:08 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Material
Replies: 13
Views: 153

Re: Midterm Material

Dr. Lavelle announced on his website that the midterm will cover equilibrium, acid & bases, thermochemistry, and thermodynamics
by 805291863
Sat Jan 25, 2020 12:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading of Tests
Replies: 18
Views: 244

Re: Grading of Tests

On the midterm last quarter, I lost all points on a calculation question following a step in which I forgot to divide by Avogadro's number. I talked to my TA about the partial credit policy, and he said that partial credit can only be given if it is specifically allotted on the rubric. So, please be...
by 805291863
Sat Jan 25, 2020 12:53 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Using different methods
Replies: 4
Views: 42

Re: Using different methods

From my experience, the method you use will be determined by the information given to you (bond enthalpies, delta H for steps of the reaction, or standard enthalpies of formation)
by 805291863
Sat Jan 25, 2020 12:49 pm
Forum: Phase Changes & Related Calculations
Topic: Delta G vs. Delta H
Replies: 3
Views: 41

Re: Delta G vs. Delta H

Endergonic and endothermic are not the same thing! Endergonic means that the reaction requires energy and is not spontaneous. Endothermic means that the reaction requires heat. Also, keep in mind that an endothermic reaction is not always endergonic and vice versa. Delta H, the temperature, and delt...
by 805291863
Sat Jan 25, 2020 12:41 pm
Forum: Phase Changes & Related Calculations
Topic: Steam Burn
Replies: 6
Views: 57

Re: Steam Burn

Here is a graph that I think helps illustrate the point Dr. Lavelle made during lecture https://www.google.com/url?sa=i&source=images&cd=&ved=2ahUKEwigq6Gdzp_nAhXjOn0KHWllDhMQjRx6BAgBEAQ&url=http%3A%2F%2Fhyperphysics.phy-astr.gsu.edu%2Fhbase%2Fthermo%2Fphase.html&psig=AOvVaw1vI32...
by 805291863
Fri Jan 24, 2020 10:11 pm
Forum: General Science Questions
Topic: Buffers
Replies: 2
Views: 45

Re: Buffers

I checked the learning outcomes for Acids & Bases and all we need to know about buffers is how to calculate their pH
by 805291863
Fri Jan 17, 2020 3:32 pm
Forum: Ideal Gases
Topic: final exam pickup
Replies: 10
Views: 207

Re: final exam pickup

Does anyone know if we also receive a key to compare our answers to?
by 805291863
Fri Jan 17, 2020 3:31 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework question 5H.1 PART B
Replies: 2
Views: 30

Re: Homework question 5H.1 PART B

When multiplying the stoichiometric coefficients of a reaction by x, the K value is raised to the power of x. This is why K=(41)^(1/2)

Also, keep in mind that the K value of the reverse reaction is K^(-1)
by 805291863
Fri Jan 17, 2020 3:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Inert Gas does not change pressure?
Replies: 7
Views: 99

Re: Inert Gas does not change pressure?

Do you have to change the volume in order to change the pressure? Or would adding a non-inert gas affect pressure as well? There are many ways to change the pressure. If you change the volume, the partial pressures can change. If you add a non-inert gas, then the partial pressures can change depend...
by 805291863
Mon Jan 13, 2020 10:00 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Units for Q- HW 5I.11
Replies: 3
Views: 49

Re: Units for Q- HW 5I.11

Okay, thank you!
by 805291863
Mon Jan 13, 2020 12:08 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Units for Q- HW 5I.11
Replies: 3
Views: 49

Units for Q- HW 5I.11

Do the concentrations used in the calculation of Q have to be in moles per liter? For example, homework problem 5I.11 give the gases with the unit mmol. Should I convert this to mol?
by 805291863
Fri Jan 10, 2020 9:44 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q and relation of [R] to [P]
Replies: 5
Views: 89

Re: Q and relation of [R] to [P]

When Q<K, [R]>[P] because [R] is the denominator in determining Q and a larger denominator will make Q smaller than K. The same logic works the other way around. However, it is important to keep in mind that when referring to [R] and [P], the value is the concentrations raised to the power of their ...
by 805291863
Fri Jan 10, 2020 9:40 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating K
Replies: 6
Views: 61

Re: Calculating K

It would be the inverse of the concentration because the value for the products would be 1
by 805291863
Fri Jan 10, 2020 9:38 am
Forum: Ideal Gases
Topic: Reaction Quotient (Q)
Replies: 8
Views: 89

Re: Reaction Quotient (Q)

It is a value you can compare to K to determine which direction the reaction is favored in to reach equilibrium
by 805291863
Thu Jan 09, 2020 5:14 pm
Forum: Ideal Gases
Topic: kc to kp
Replies: 2
Views: 41

Re: kc to kp

I believe you can convert Kc to Kp and vice versa. Here is the link to a video working through this concept: https://www.brightstorm.com/science/chemistry/chemical-equilibrium/tips-for-converting-to-kp-from-kc/
by 805291863
Thu Jan 09, 2020 5:12 pm
Forum: Ideal Gases
Topic: K based on phases
Replies: 4
Views: 58

Re: K based on phases

When determining K, only reactants and products that are aqueous or a gas are considered.

Also, a reaction's considered values will either all be pressures or all be concentrations.
by 805291863
Sat Dec 07, 2019 3:14 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain & Solutions
Replies: 4
Views: 156

Re: Acid Rain & Solutions

Can NO2 also react with water to form HNO2 and HNO3?
by 805291863
Sat Dec 07, 2019 3:12 pm
Forum: Naming
Topic: Transition Metal Latin Names
Replies: 3
Views: 91

Transition Metal Latin Names

Does anyone know which transition metals need to be named using their latin name in coordination compound naming?
by 805291863
Sat Dec 07, 2019 3:03 pm
Forum: Industrial Examples
Topic: What do we need to know?
Replies: 15
Views: 343

Re: What do we need to know?

I believe that EDTA holds industrial applications when it bonds with metal ions and forms a coordination complex
by 805291863
Sat Dec 07, 2019 2:58 pm
Forum: Biological Examples
Topic: heme complex chelating?
Replies: 3
Views: 87

Re: heme complex chelating?

The porphyrin ligand in polydentate (tetradentate, to be specific), making myoglobin a chelating complex. As to the shape of myoglobin, I believe we do not need to know its shape. However, the "marshmallow" practice problems included a question on the shape of the heme complex. In the revi...
by 805291863
Sat Dec 07, 2019 10:35 am
Forum: Biological Examples
Topic: Main examples
Replies: 2
Views: 60

Re: Main examples

There were multiple examples that Dr. Lavelle touched on during lecture, but I would say that the hemoglobin example is particularly as he spend a good chunk of time on it and since it serves such a vital role.
by 805291863
Sun Dec 01, 2019 11:41 am
Forum: Administrative Questions and Class Announcements
Topic: Asterisks on Chemistry Community
Replies: 1
Views: 46

Asterisks on Chemistry Community

What do the asterisks next to certain topics on Chemistry Community mean? Are the topics that will be covered on examinations?
by 805291863
Sun Dec 01, 2019 11:37 am
Forum: Polyprotic Acids & Bases
Topic: Polyprotic Acid Reactions- Loss of Proton(s)?
Replies: 2
Views: 93

Polyprotic Acid Reactions- Loss of Proton(s)?

In a reaction with a polyprotic acid, does it lose one of it protons and then the others in separate reactions or does it donate multiple protons at once?
by 805291863
Sun Dec 01, 2019 11:34 am
Forum: Lewis Acids & Bases
Topic: Neutralization Reactions
Replies: 2
Views: 94

Re: Neutralization Reactions

When selecting the acid and base, my thought process would be to add H to the anion and OH to the cation. The compound with the H would be your acid and the compound with OH would be your base. In a neutralization reaction, the H and OH would form H2O and the remaining anion and cation would form th...
by 805291863
Sun Dec 01, 2019 11:30 am
Forum: Amphoteric Compounds
Topic: Examples of amphoteric compounds
Replies: 5
Views: 50

Re: Examples of amphoteric compounds

In addition to the diagonal band of amphoteric compounds, don't forget that H2O is amphoteric too!
by 805291863
Sun Dec 01, 2019 11:27 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelating Ligands
Replies: 2
Views: 55

Re: Chelating Ligands

If a ligand is polydentate, then it is a chelating ligand. To determine if a ligand is polydentate, look at the number of electron pairs it can donate. If it is more than 1 electron pair, then it is polydentate
by 805291863
Sun Nov 24, 2019 3:00 pm
Forum: General Science Questions
Topic: Review Sessions for Final
Replies: 7
Views: 147

Review Sessions for Final

Does anyone know when review sessions for the final will begin?
by 805291863
Sun Nov 24, 2019 2:56 pm
Forum: Lewis Acids & Bases
Topic: Strong Acids
Replies: 8
Views: 159

Strong Acids

Are HCl, HBr, HNO3, and H2SO4 the only strong acids we are required to know? What about HI and HClO4?
by 805291863
Sun Nov 24, 2019 2:52 pm
Forum: Naming
Topic: Naming & Dashes
Replies: 1
Views: 48

Naming & Dashes

When are we supposed to use dashes in the name of coordination compounds?
by 805291863
Sun Nov 24, 2019 2:50 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Lewis Acids
Replies: 4
Views: 66

Re: Lewis Acids

From my understanding, Lewis acids and Bronsted acids are the same. However, the concept used to identify them are different. Based on the Lewis definition, an acid receives and electron pair. Based on the Bronsted definition, an acid donates a proton
by 805291863
Sun Nov 24, 2019 2:47 pm
Forum: Naming
Topic: Naming
Replies: 3
Views: 42

Re: Naming

Knowing either column of naming will result in the correct name for this class, but Dr. Lavelle did mention that the column titled "Name" will be the conventionally used naming system
by 805291863
Sat Nov 16, 2019 3:49 pm
Forum: Sigma & Pi Bonds
Topic: Recognizing Sigma and Pi bonds
Replies: 4
Views: 68

Re: Recognizing Sigma and Pi bonds

sarahsalama1G wrote:did we cover sigma and pi bonds? Are we going to cover them this week?


We have not covered sigma and pi bonds yet, but Dr. Lavelle will be covering them during the beginning portion of Monday's lecture. FYI, they will be on the Test 2 occurring this week
by 805291863
Sat Nov 16, 2019 3:46 pm
Forum: Sigma & Pi Bonds
Topic: Sigma & Pi Bonds
Replies: 4
Views: 79

Re: Sigma & Pi Bonds

Does anyone know what type of questions we will be asked regarding sigma and pi bonds? For example, will we just have to identify how many of each type is present in a bond? Will we have to be able to draw it?
by 805291863
Sat Nov 16, 2019 3:44 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Studying
Replies: 14
Views: 300

Re: Final Studying

I've also looked at finals from the previous years to have an idea of how the final will be different from the midterm. I think that'd be helpful for you too!
by 805291863
Sat Nov 16, 2019 3:40 pm
Forum: Administrative Questions and Class Announcements
Topic: Class Grading
Replies: 3
Views: 73

Re: Class Grading

Essentially, 465/500 will guarantee you a solid A in this class, but having a lower score does not eliminate the potential of getting an A at the end of the quarter.
by 805291863
Fri Nov 15, 2019 4:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR and Lewis Structures
Replies: 2
Views: 35

VSEPR and Lewis Structures

Now that we have learned the VSEPR model for determining molecular shapes, does this mean a correct lewis structure (for the purposes of assessments) needs to be drawn in a manner similar to its molecular geometry? Examples: -Should the lewis structure of BF3 be drawn with the F's equidistant from e...
by 805291863
Sun Nov 10, 2019 10:41 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: dipole moment and intermolecular forces
Replies: 3
Views: 78

Re: dipole moment and intermolecular forces

In addition, the intermolecular forces produced by dipole moments would be ion-dipole, dipole-dipole, or dipole-induced dipole interactions.
by 805291863
Sun Nov 10, 2019 10:37 am
Forum: Dipole Moments
Topic: Van Der Waals
Replies: 5
Views: 91

Re: Van Der Waals

As long as a molecule has electrons, it will have Van Der Waals interactions. Therefore, all molecules do
by 805291863
Sun Nov 10, 2019 10:32 am
Forum: Dipole Moments
Topic: Interactions
Replies: 4
Views: 60

Re: Interactions

During lecture, Dr. Lavelle mentioned that they are the same for the purposes of this class
by 805291863
Sun Nov 10, 2019 10:30 am
Forum: Bond Lengths & Energies
Topic: Ionic/covalent Character
Replies: 3
Views: 70

Re: Ionic/covalent Character

The more ionic the nature of the salt is, the more soluble the salt will be in water
by 805291863
Sun Nov 10, 2019 10:27 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle Quantity
Replies: 3
Views: 58

Re: Bond Angle Quantity

I believe it is necessary to know the bond angles of the most standard shapes. However, for molecular shapes in which lone pairs are present, it is only necessary to know the bond angle in relation to the bond angle in the standard shape
by 805291863
Sun Nov 03, 2019 3:56 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Dino Nuggets 12b
Replies: 2
Views: 61

Re: Dino Nuggets 12b

In the case of ClO4-, the lowest energy Lewis structure must have one atom with a formal charge of -1. Because O is more electronegative than Cl, it is more stable when the O has the negative formal charge. Therefore, 3 Cl-O double bonds and 1 Cl-O single bond is the best lewis structure.
by 805291863
Sun Nov 03, 2019 3:46 pm
Forum: Lewis Structures
Topic: Exceptions to octet rule
Replies: 4
Views: 45

Re: Exceptions to octet rule

The other exception to the octet rule is atoms that do not need 8 electrons to be stable. H and Li only want 2 electrons, and B can be stable with 6 electrons.
by 805291863
Sun Nov 03, 2019 3:30 pm
Forum: DeBroglie Equation
Topic: Dino Nugget Problem 8c
Replies: 1
Views: 58

Re: Dino Nugget Problem 8c

You may need to recheck your work in 8b where you find the frequency of the light. The value I calculated was 6.78x10^14 Hz.

However, to directly answer your question, the value you calculated does not fall within the range of visible light.
by 805291863
Sun Nov 03, 2019 12:13 am
Forum: Administrative Questions and Class Announcements
Topic: Bruincast
Replies: 4
Views: 100

Re: Bruincast

I have checked. The lectures are not bruincasted
by 805291863
Sat Nov 02, 2019 3:18 pm
Forum: DeBroglie Equation
Topic: Lyndon's Workshop Worksheet Problem
Replies: 3
Views: 126

Re: Lyndon's Workshop Worksheet Problem

The equation applies to electromagnetic radiation, which a photon behaves like
by 805291863
Sun Oct 27, 2019 3:15 pm
Forum: Lewis Structures
Topic: Lewis Structure of Ions
Replies: 6
Views: 79

Lewis Structure of Ions

To clarify, do I need to bracket the Lewis Structure of an ion and note the ion's charge in the top right corner outside of the bracket?
by 805291863
Sun Oct 27, 2019 3:11 pm
Forum: Resonance Structures
Topic: Resonance Structures in relation to Formal Charge
Replies: 3
Views: 53

Re: Resonance Structures in relation to Formal Charge

Individual atoms within resonance structures will have different formal charges than other versions. This is because it can have a double bond in one structure and a single bond in another structure which would change the formal charge value of each. Does this mean that all resonance structures are...
by 805291863
Sun Oct 27, 2019 3:04 pm
Forum: Lewis Structures
Topic: Central Atom
Replies: 2
Views: 63

Central Atom

Why is the atom with the lowest ionization energy the central atom?
by 805291863
Sun Oct 27, 2019 2:55 pm
Forum: Resonance Structures
Topic: Resonance Structures in relation to Formal Charge
Replies: 3
Views: 53

Resonance Structures in relation to Formal Charge

I'm a bit confused on the relationship between resonance structures and formal charge. Will the formal charges of different resonance structures always be the same?
by 805291863
Sun Oct 27, 2019 2:52 pm
Forum: Octet Exceptions
Topic: Exceeding the Octet Rule
Replies: 5
Views: 80

Exceeding the Octet Rule

During lecture, Dr. Lavelle explained that P, S, and Cl can accommodate more than 8 valence electrons. Does this mean they can have 10 valence electrons and only 10? In other words, do they only use one d-orbital when bonding with other atoms?
by 805291863
Sat Oct 19, 2019 10:19 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron configuration for Tungsten
Replies: 1
Views: 42

Re: Electron configuration for Tungsten

If you look closely at Tungsten's location on the periodic table, you'll notice that it follows a f-block of elements (Lanthanum-Lutetium) that is footnoted below the rest of the periodic table. So, tungsten's electron configuration will include the 4f orbital.
by 805291863
Sat Oct 19, 2019 10:12 pm
Forum: Administrative Questions and Class Announcements
Topic: Posting Image
Replies: 3
Views: 68

Re: Posting Image

Image
by 805291863
Sat Oct 19, 2019 6:30 pm
Forum: Administrative Questions and Class Announcements
Topic: Posting Image
Replies: 3
Views: 68

Posting Image

I've found that sometimes I want to post in image as part of a question or response. How do I do this?
by 805291863
Sat Oct 19, 2019 5:59 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 4s vs. 3d
Replies: 6
Views: 81

Re: 4s vs. 3d

The electron-electron repulsion within the 3d orbital cause it to have a higher energy than the 4s orbital
by 805291863
Sat Oct 19, 2019 5:54 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: E configuration of ions
Replies: 2
Views: 47

Re: E configuration of ions

When an atom becomes an ion, it either loses its valence electrons or gains electrons to fill its outermost shell. In relation to the electron configuration, this means that the ion either has the same electron configuration as the atom but without the outermost subshell (the last segment of the ele...
by 805291863
Sat Oct 12, 2019 3:54 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Decreasing gap between energy level
Replies: 6
Views: 127

Re: Decreasing gap between energy level

The pull of the nucleus decreases at higher energy levels because of the distance and because of the shielding provided by the electrons in lower energy levels.
by 805291863
Sat Oct 12, 2019 3:49 pm
Forum: Einstein Equation
Topic: Atomic Spectra
Replies: 2
Views: 110

Re: Atomic Spectra

Maybe the second question is asking if the calculated energies can be experimentally detected?
by 805291863
Sat Oct 12, 2019 3:47 pm
Forum: Properties of Electrons
Topic: Electron After Excited State
Replies: 7
Views: 115

Re: Electron After Excited State

When an excited election falls back to its original state, is the fall a gradual one (e.g. electron from n=3 to n=2 then to n=1) or does it happen in one step? If its a gradual one, is a photon released for each fall or is only one photon released for the entire process?
by 805291863
Sat Oct 12, 2019 3:42 pm
Forum: Properties of Light
Topic: Wavelength
Replies: 4
Views: 73

Re: Wavelength

I completely agree with what the previous person said. However, I want to add that wavelength and frequency are inversely related because c= λ ν. Since c is a constant, wavelength increases when frequency decreases and vice versa.
by 805291863
Sat Oct 12, 2019 3:32 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Groups of Spectral Lines
Replies: 1
Views: 54

Groups of Spectral Lines

Professor Lavelle mentioned that UV light is when a high energy e- drops to the n=1 state, visible light is for the n=2 state, and infrared is for the n=3 state. How does this apply to gamma rays, x-rays, microwaves, and radio waves?
by 805291863
Thu Oct 03, 2019 9:21 pm
Forum: Student Social/Study Group
Topic: Study Group Fall 2019
Replies: 32
Views: 1811

Re: Study Group Fall 2019

I'm interested too! What do I have to do to join?
by 805291863
Thu Oct 03, 2019 9:18 pm
Forum: Empirical & Molecular Formulas
Topic: Test Materials
Replies: 13
Views: 234

Re: Test Materials

Does anybody know if we are required to know the common polyatomic ions (their names, formula, and charges) for the quiz on Week 2?
by 805291863
Thu Oct 03, 2019 9:13 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Rounding
Replies: 12
Views: 391

Re: Rounding

What I do is I use one more digit that the number of significant digits in the given values during all my calculations. At the very, I round my answer to the appropriate number of significant digits.
by 805291863
Thu Oct 03, 2019 9:04 pm
Forum: Balancing Chemical Reactions
Topic: State Symbols
Replies: 5
Views: 168

Re: State Symbols

My TA said that we currently aren't required to include the states of matter in the chemical equations, but we will have to later in the course
by 805291863
Thu Oct 03, 2019 8:58 pm
Forum: SI Units, Unit Conversions
Topic: unit conersations
Replies: 7
Views: 144

Re: unit conersations

If the units of a given value don't match with the units of a conversion factor (e.g. molar mass) or are different from the units of the answer you are looking for, definitely convert your units

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