Search found 81 matches

by Nick Lewis 4F
Sun Feb 09, 2020 11:11 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: combustion rxn
Replies: 2
Views: 24

Re: combustion rxn

What was the equation that Lavelle shared for calculating the change in mols for a combustion rxn? I dont remember exactly what you're referencing, but it is relatively straight forward to calculate the change in moles in a combustion reaction, just make sure you identify the right stoichiometric c...
by Nick Lewis 4F
Sun Feb 09, 2020 11:07 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated vs Closed
Replies: 29
Views: 97

Re: Isolated vs Closed

WIll it always be specified if the item is insulated? Like are we expected to know certain things they reference are insulated? What if its hard to distinguish, or is it pretty clear whether or not its insulated?
by Nick Lewis 4F
Sun Feb 09, 2020 11:03 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Temp vs Vol
Replies: 3
Views: 15

Temp vs Vol

One thing I am a bit hung up on while studying is why temperature is the only variable that can impact K, wheres vol and pressure changes only impact Q. Can someone break this down a little bit for me?
by Nick Lewis 4F
Sun Feb 09, 2020 10:40 pm
Forum: Van't Hoff Equation
Topic: MIdterm
Replies: 1
Views: 35

MIdterm

Just to put it out there... do we have to be able to recognize the name of stuff like this? Can't you just derive these equations from simpler equations? Essentially im just a little confused why rearrange the equation and call it something else? I dont really see the purpose in this
by Nick Lewis 4F
Sun Feb 09, 2020 10:34 pm
Forum: Calculating Work of Expansion
Topic: Isothermal
Replies: 17
Views: 69

Re: Isothermal

An isothermal process is a change of system where the temperature remains constant. Therefore, delta U would be equal to 0. I agree with this, for example, in pizza rolls review session they showed how when t = o, delta U = 0, therefore q = -w, which can come in useful knowing some of the types of ...
by Nick Lewis 4F
Sun Feb 02, 2020 11:40 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Spontaneous vs. Energetically Favorable
Replies: 3
Views: 7

Re: Spontaneous vs. Energetically Favorable

So all energetically favorable reactions are spontaneous but not all spontaneous reactions are energetically favorable?
by Nick Lewis 4F
Sun Feb 02, 2020 11:36 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: Third Law concept and problem types
Replies: 4
Views: 254

Re: Third Law concept and problem types

Yes, essentially the third law of thermodynamics is saying that at 0 degrees K, there is no vibrational, rotational, or translational entropy. The only possible entropy results from positional and residual. Thus, knowing the Boltzmann equation would come in handy when asked a question about the res...
by Nick Lewis 4F
Sun Feb 02, 2020 11:30 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Week 4 lecture 3 calculating W question
Replies: 2
Views: 12

Re: Week 4 lecture 3 calculating W question

Does anyone know the point in microstates? I understood lavelle's discussion about this and the Boltzmann equation, but am having trouble understanding its applications. What is the point in making these distinctions?
by Nick Lewis 4F
Sun Feb 02, 2020 10:48 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isometric/Isochoric
Replies: 11
Views: 349

Re: Isometric/Isochoric

What is the difference in isometric/osochoric? Is this something you think we will need to distinguish between on the midterm?
by Nick Lewis 4F
Sun Feb 02, 2020 10:38 pm
Forum: Calculating Work of Expansion
Topic: work integral
Replies: 6
Views: 33

Re: work integral

Does anyone know if we are going to have to deal with inconsistent pressure? Are we expected to know how to use calculus in this class?
by Nick Lewis 4F
Sun Jan 26, 2020 11:30 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: State Functions
Replies: 4
Views: 18

Re: State Functions

What does it mean to be an "internal system"? What is the distinction between types of systems?
by Nick Lewis 4F
Sun Jan 26, 2020 11:28 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Kw Equations
Replies: 9
Views: 29

Re: Kw Equations

Pretty much this is a way of saying that pH + pOH = 14, but it is showing it in terms of the concentrations of [H30+] and [OH-]. I know these equations are usually always given on the equation sheet, so u can deduce subsequent equations from it.
by Nick Lewis 4F
Sun Jan 26, 2020 11:25 pm
Forum: Calculating Work of Expansion
Topic: Reversible Process - infinitesimal changes
Replies: 2
Views: 16

Re: Reversible Process - infinitesimal changes

By saying it is infinitesimal changes, it is pretty much saying it is continuous. Pretty much it will slowly grow to the equilibrium point, not grow or shrink from point to point
by Nick Lewis 4F
Sun Jan 26, 2020 11:23 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Predicting Molar Heat Capacity
Replies: 3
Views: 22

Re: Predicting Molar Heat Capacity

I believe Professor Lavelle said something about correlating with size. As the person above me said, complexity (higher mass) would probably mean it has a higher heat capacity in comparison to a simple compound with smaller mass. I think thats an accurate description. Pretty much I think if the com...
by Nick Lewis 4F
Sun Jan 26, 2020 11:19 pm
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 8
Views: 23

Re: Hess's Law

Are there any other laws we have to remember pertaining to this? I know we went over 3 methods to this, but was this the only one given the name of a law?
by Nick Lewis 4F
Sun Jan 19, 2020 7:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When do we use the equilibrium sign?
Replies: 7
Views: 21

Re: When do we use the equilibrium sign?

Is it incorrect to use an equilibrium sign for strong acids/ bases?
by Nick Lewis 4F
Sun Jan 19, 2020 7:45 pm
Forum: Phase Changes & Related Calculations
Topic: Autoprotolysis
Replies: 15
Views: 80

Re: Autoprotolysis

Lavelle talked about autoprotolysis a lot throughout lectures, so I wouldnt be surprised to see it show up on the test. Definitions above are good, i would say definitely know the equation and be able to explain it, which shouldnt be that hard if you have a rough understanding of what it is.
by Nick Lewis 4F
Sun Jan 19, 2020 7:43 pm
Forum: Phase Changes & Related Calculations
Topic: lecture on 1/17
Replies: 3
Views: 29

Re: lecture on 1/17

As said above, Lavelle made it clear he was not going over new material. He ran through roughly 3 practice problems, and given that there is no class on monday this was a little review for the test in the coming week. Everything on equilibrium, acids/ bases, and ICE charts. Shouldn't be too bad but ...
by Nick Lewis 4F
Sun Jan 19, 2020 7:41 pm
Forum: Ideal Gases
Topic: When to use this equation
Replies: 14
Views: 68

Re: When to use this equation

PV= nRT is an overarching equation that can be manipulated to define a lot of different laws within chemistry, but I think the main thing to notice is the effect temperature has on pressure and volume, and the inversely proportional relationship between p and v
by Nick Lewis 4F
Sun Jan 19, 2020 7:39 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Shift Of Reaction
Replies: 4
Views: 16

Shift Of Reaction

What exactly does it mean for the reaction to shift left or to shift right? does it mean there is more products/reactants at equilibrium or it has to produce more in the direction to reach the same ratio at equilibrium again
by Nick Lewis 4F
Sun Jan 12, 2020 10:42 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Chatelier's Principle
Replies: 7
Views: 25

Re: Chatelier's Principle

Chatelier's principle can be used to see which direction a reaction will proceed in response to a change in concentration or pressure. For example, if more reactants are added, therefore increasing concentration, Le Chatelier's principle tells us that the reaction will move forward in order to mini...
by Nick Lewis 4F
Sun Jan 12, 2020 10:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Hw for next week
Replies: 19
Views: 64

Re: Hw for next week

From experience in 14A, the homework problems are really more for your understanding than for credit... just pick any problem relating to something we have gone over and he will accept it, it's more repition that will help you study and do better on the tests.
by Nick Lewis 4F
Sun Jan 12, 2020 10:32 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Quadratic
Replies: 2
Views: 35

Re: Quadratic

It can get easy to get all your units mixed up, so make sure you are consistenly measuring Kc or Kp depending on the context
by Nick Lewis 4F
Sun Jan 12, 2020 10:25 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Comparing K
Replies: 9
Views: 38

Re: Comparing K

When they say equilibrium lies to the right, it means that the forward reaction needs to carry out more before it reaches equlibrium, so more product needs to be formed
by Nick Lewis 4F
Sun Jan 12, 2020 10:16 pm
Forum: Ideal Gases
Topic: Gas Laws
Replies: 6
Views: 52

Re: Gas Laws

On that note, do you guys think we need to know the isolated equations or is the ideal gas law the only thing we really need to remember?
by Nick Lewis 4F
Sat Dec 07, 2019 10:11 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: -ido vs -o
Replies: 5
Views: 46

-ido vs -o

Why in some of the examples in the book (pg. 723) are anion ligands like CN- named cyanido, but then in other complexes named cyano? IF it is overall positively charged is it cyano and if the complex is overall negatively charged is it cyanido? Or is it just IUPAC confusion, and I should only use th...
by Nick Lewis 4F
Sat Dec 07, 2019 9:53 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Practice Problem
Replies: 2
Views: 23

Practice Problem

FOr [Fe(NCS)(OH2)5]2+ how do you name iron at the end? I know you use ferrate for a negatively charged complex, but what do you use when it is positively charged?
by Nick Lewis 4F
Sat Dec 07, 2019 9:02 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Why can CO3(2-) be a mono/bidentate ligand
Replies: 3
Views: 5502

Re: Why can CO3(2-) be a mono/bidentate ligand

Normally Carbonate is monodentate, because it only has 120 degrees between its Oxygens, so two oxygens cannot bind to the same metal. However, in some cases carbonate bonds to two different metals, making it bidentate. If it is bonding to two different metals, then isn't it not a coordination compo...
by Nick Lewis 4F
Sat Dec 07, 2019 8:36 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: chelating ligands [ENDORSED]
Replies: 21
Views: 1890

Re: chelating ligands [ENDORSED]

Does anyone know what Dr. Lavelle means when he says:
atom with lone pair --- spacer atom --- spacer atom --- atom with lone pair
The only part i dont understand is spacer atom. What does spacer atom mean? Conceptually I see why C is the correct answer i am just unfamiliar with this terminology
by Nick Lewis 4F
Sat Dec 07, 2019 8:31 pm
Forum: Naming
Topic: Abbreviations
Replies: 6
Views: 46

Abbreviations

On the exam, are we allowed to write oxalato as (ox) or do we have to say (C2O4)? Can we say (en) or do we have to say NH2CH2CH2NH2? Is one better than the other or are they interchangeable without losing points?
by Nick Lewis 4F
Sat Dec 07, 2019 8:13 pm
Forum: Naming
Topic: Cation vs. Anion Transition Metal
Replies: 3
Views: 31

Cation vs. Anion Transition Metal

For example, on 9C.1, the transition metal is named cobalt for part B, but it is cobaltate for part C. How do you know which name to use? if the complex is anionic, do you name the transition metal + -ate or was this just a coincidence? Sorry, i dont remember what the rule for naming coord. compound...
by Nick Lewis 4F
Sun Dec 01, 2019 11:54 pm
Forum: Polyprotic Acids & Bases
Topic: Spectator ions
Replies: 3
Views: 395

Re: Spectator ions

I know usually you can just determine spectator ions based on the ions that are not present in the reaction formula where you only write the ions that contribute to the actual reaction that occurs. Will we have to know how to identify them for the final/ write out these equations?
by Nick Lewis 4F
Sun Dec 01, 2019 11:41 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Strong and Weak Acids
Replies: 7
Views: 43

Re: Strong and Weak Acids

Does anyone have a definite answer about if we need to know a list of strong acids and bases?
I remember we are only going to have to determine the pH of strong acids, but will we be asked to identify/ differentiate strong acids from weak acids
by Nick Lewis 4F
Sun Dec 01, 2019 11:29 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Conjugate Seesaw
Replies: 1
Views: 14

Conjugate Seesaw

I understand Ka and Kb, but what is a conjugate seesaw? How will questions be brought up on this topic on the final?
by Nick Lewis 4F
Sun Dec 01, 2019 11:21 pm
Forum: *Stereochemistry
Topic: What's a stereocenter?
Replies: 5
Views: 932

Re: What's a stereocenter?

Is it only a stereocenter if all the atoms are different, or can 2 or more atoms be the same?
by Nick Lewis 4F
Sun Dec 01, 2019 11:18 pm
Forum: Industrial Examples
Topic: For the Final
Replies: 3
Views: 57

Re: For the Final

What does an industrial example look like? Does industrial refer to the context of how the compound is applied, or something else? Trying to study and see if this is something i need to study more
by Nick Lewis 4F
Sun Dec 01, 2019 11:09 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate ligands
Replies: 2
Views: 26

Re: Polydentate ligands

Can someone explain to my what denticity measures? I have been following pretty closely but the language is getting really complex and I am getting really confused
by Nick Lewis 4F
Sun Nov 24, 2019 5:21 pm
Forum: Amphoteric Compounds
Topic: Amphiprotic
Replies: 11
Views: 75

Re: Amphiprotic

Is H20 amphiprotic?
by Nick Lewis 4F
Sun Nov 24, 2019 5:16 pm
Forum: *Crystal Field Theory
Topic: Crystal Field Theory
Replies: 5
Views: 697

Re: Crystal Field Theory

Did Lavelle go over these theories in class? I don’t have any recollection of it and don’t wanna get hit by a curveball on the final. Where do they originate from, how would it be tested , etc.
by Nick Lewis 4F
Sun Nov 24, 2019 5:06 pm
Forum: Biological Examples
Topic: Biological Applications to Know
Replies: 3
Views: 51

Re: Biological Applications to Know

Are the biological implications relevant for this class? I thought Lavelle just likes discussing the implications but it’s not actually necessary to know for the tests. I could be wrong but that was just my understanding up to this point
by Nick Lewis 4F
Sun Nov 24, 2019 5:04 pm
Forum: Naming
Topic: Order
Replies: 4
Views: 20

Re: Order

How do these topics come into question on the test? I don’t really understand the concept of naming these things and their application
by Nick Lewis 4F
Sun Nov 24, 2019 4:59 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordinate covalent bonds
Replies: 5
Views: 30

Re: Coordinate covalent bonds

I missed this lecture. What is a coordination compound and what is a ligand? I am so confused it all sounded so complicated and I had to miss lecture so I feel really behind.
by Nick Lewis 4F
Sun Nov 24, 2019 4:52 pm
Forum: Lewis Acids & Bases
Topic: lewis vs. bronsted
Replies: 10
Views: 59

Re: lewis vs. bronsted

Is donating a proton really the same as accepting an electron pair? What is the distinction and when does it come into play or are they exactly the same thing just interchangeable terms?
by Nick Lewis 4F
Sun Nov 17, 2019 10:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing molecules
Replies: 12
Views: 73

Re: Drawing molecules

Does it matter in what order we draw the atoms in the molecule? I forget what Dr. Lavelle said about structuring our drawing, although I know he said we need to know how to identify the molecules.
by Nick Lewis 4F
Sun Nov 17, 2019 10:42 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Shapes
Replies: 5
Views: 33

Re: Shapes

Does anyone know the shape of a molecule that has 2 bonding pairs of electrons and 3 unbonding pairs of electrons? Just trying to think of different combos that didnt come up during lecture.
by Nick Lewis 4F
Sun Nov 17, 2019 10:39 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: ion-ion intermolecular forces and ionic bonds
Replies: 2
Views: 13

Re: ion-ion intermolecular forces and ionic bonds

Yes, i think the terms are interchangeable. Pretty much the cation donates the electrons to the anion that holds all the electrons after and accepts the electrons.
by Nick Lewis 4F
Sun Nov 17, 2019 8:12 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: Size and Electronegativity difference
Replies: 3
Views: 43

Re: Size and Electronegativity difference

Do you have any example questions of how this would be tested? I understand the concepts but dont see how it could be tested on a test
by Nick Lewis 4F
Sun Nov 17, 2019 8:09 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: This Week Test
Replies: 12
Views: 69

Re: This Week Test

Have we gone over sigma and pi bonds yet? Do we have any more information about what exact material will be tested?
by Nick Lewis 4F
Sun Nov 17, 2019 8:08 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: 39

Re: Boiling Points

Essentially, does this mean that boiling points have a direct correlation to electronegativity? I would think that if an atom is more electronegative then there is a stronger bond and thus a higher boiling point.
by Nick Lewis 4F
Sun Nov 10, 2019 10:33 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: pi bonds
Replies: 3
Views: 411

Re: pi bonds

What do sigma bonds look like versus pi ponds? Can you visually differentiate between the two or is it just a convention to describe them?
by Nick Lewis 4F
Sun Nov 10, 2019 10:30 pm
Forum: Hybridization
Topic: Why is hybridization necessary?
Replies: 3
Views: 25

Re: Why is hybridization necessary?

What does hybridization look like? Is it just a way to describe how the electrons are arranged, or do the geometric e- distributions blend together and there a greater region where e- can be located?
by Nick Lewis 4F
Sun Nov 10, 2019 10:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Writing e- Configurations
Replies: 15
Views: 89

Re: Writing e- Configurations

This is a good question- usually the shorthand convention is to use the last noble gas and then write out the configuration. However, when you first learn them, they usually want to see you write them out all the way. It isn't too difficult and pretty self explanatory.
by Nick Lewis 4F
Sun Nov 10, 2019 10:24 pm
Forum: Bond Lengths & Energies
Topic: negative Ep
Replies: 5
Views: 40

Re: negative Ep

I think Ep is always negative because when 2 molecules interact, it is usually a likely reaction when Ep is negative. It is likely to happen and when they interact, energy is released, hence the negative sign.
by Nick Lewis 4F
Sun Nov 10, 2019 10:18 pm
Forum: Electronegativity
Topic: Iodine
Replies: 6
Views: 30

Re: Iodine

Isn't there a greater shielding effect because iodine has a larger atomic radius than the other molecules? Im having trouble conceptualizing this becuase I would think F2 would have a stronger interaction because fluorine is the most electronegative atom and I thought they want the electrons the most.
by Nick Lewis 4F
Sun Nov 03, 2019 11:58 pm
Forum: Coordinate Covalent Bonds
Topic: Electronegativity
Replies: 12
Views: 403

Re: Electronegativity

Can someone explain how shielding works? I understand the concept as when there are more expanded shells of electrons the electrons are further away and the ones in the furthest shell are not pulled on as much, but is it the idea that the ones closer to the nucleus are "stealing" more of t...
by Nick Lewis 4F
Sun Nov 03, 2019 11:55 pm
Forum: Dipole Moments
Topic: Induced dipole induced dipole interaction
Replies: 2
Views: 30

Induced dipole induced dipole interaction

If one dipole is induced and the induces another dipole, how does this interaction even begin? I am having trouble rationalizing this conceptually because I don't see how these molecules can induce a dipole when there is not something with a charge to incite it.
by Nick Lewis 4F
Sun Nov 03, 2019 11:52 pm
Forum: Resonance Structures
Topic: Resonance structures
Replies: 6
Views: 30

Re: Resonance structures

Does it count as a resonance structure if it isn't the best way of arranging the compound? For example, we went over how to draw N2O at the review session and there were a bunch of different ways, but they weren't necessarily the best. Are resonance structure any variable form, or just variable form...
by Nick Lewis 4F
Sun Nov 03, 2019 11:49 pm
Forum: Electronegativity
Topic: Comparing electronegativities
Replies: 2
Views: 23

Comparing electronegativities

How do you compare the electronegativities of elements across rows/ columns? Like how do you compare oxygen and chlorine when they are in equivalent positions of comparison? IS this something we would have to know how to explain on the midterm?
by Nick Lewis 4F
Sun Nov 03, 2019 11:47 pm
Forum: Resonance Structures
Topic: Octet
Replies: 13
Views: 84

Re: Octet

What is the basis of the octet? LIke where does the logic come from and like how do we know some only want 8 when other elements want more or less? I know its the s2 and p6, but why does this mean Be, B can't have 8?
by Nick Lewis 4F
Sun Oct 27, 2019 11:51 pm
Forum: Octet Exceptions
Topic: More than 8 valence e-
Replies: 8
Views: 62

More than 8 valence e-

Can someone explain why sulfur and those other atoms can take more than 8 electrons? I remember Dr. Lavelle had a good explanation in class but I am having trouble coming up with his explanation while trying to study.
by Nick Lewis 4F
Sun Oct 27, 2019 11:48 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 2839

Re: Test 1 [ENDORSED]

I thought we were gonna be given partial credit, but my TA saw one tiny sign mistake in my problem and took away all points for that question (8 POINTS). When I asked him about it he said "you say wrong answer, you get no credit"... anyone else have this problem? Already made sure I switch...
by Nick Lewis 4F
Sun Oct 27, 2019 11:45 pm
Forum: Ionic & Covalent Bonds
Topic: 4s before 3d
Replies: 4
Views: 40

Re: 4s before 3d

Nare Arakelian Dis 3E wrote:Why is 3d at a lower energy level than 4s?


3d is at a lower energy level than 4s because it is at the n = 3 level. At the n = 3 level, there is less energy then the 4s. Dr. Lavelle went over how to determine these quantum numbers in lecture and has shown the differences in energy at each n level.
by Nick Lewis 4F
Sun Oct 27, 2019 11:32 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 6
Views: 32

Re: Electron Affinity

How can they measure the electron affinity? The way I think of it, I thought it was just described as how badly an atom wants to gain an electron. SO it takes less energy to add one as you move across the periodic table cause it gets closer to filling the octet. How can there be a negative energy?
by Nick Lewis 4F
Sun Oct 27, 2019 11:13 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electrostatic potential energy
Replies: 1
Views: 11

Electrostatic potential energy

I unfortunately had to miss this lecture, but I was reviewing the notes from class and got a little confused when I was looking at this. this is E = q1q2/r. How does one determine the charge of each electron, and how can you experimentally determine the distance between these charges? Just curious b...
by Nick Lewis 4F
Sun Oct 27, 2019 11:09 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Noble gas electron configurations
Replies: 3
Views: 25

Re: Noble gas electron configurations

I'm sure the textbook messed up. The first 2 electrons will occupy the 1s orbital, thus denoted as 1s2. It then follows the sequence of 1s2 2s2 2p6...
It doesn't really get messy in configurations until you reach period 4 where 4s fills before 3d.
by Nick Lewis 4F
Sun Oct 20, 2019 11:29 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Advice for studying
Replies: 58
Views: 544

Re: Advice for studying

I think there's a lot of ways you can elaborate on learning in class. What I do is I review my notes, see what resources are online on Dr. Lavelle's website, and then sometimes I will look up topics online and read about them. I will go on youtube and find people that explain concepts more in depth ...
by Nick Lewis 4F
Sun Oct 20, 2019 11:16 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: s-, p-, d- ,f- orbitals
Replies: 10
Views: 83

Re: s-, p-, d- ,f- orbitals

I have a general question. The electron density distributions were illustrated for s p and d orbitals. What exactly do these show? For example, p-orbitals show 2 lobes on either side of the nucleus. Can electrons be found anywhere within the lobe on either side, or is it just on the border of these ...
by Nick Lewis 4F
Sun Oct 20, 2019 11:07 pm
Forum: Quantum Numbers and The H-Atom
Topic: Orbitals
Replies: 4
Views: 32

Re: Orbitals

What about when there are 2 electons in the s-orbital? Is it easier to remove 1 electron over the other depending on where they are orbiting around the nucleus, or is it just as easy to remove one electron as it is the other? Just wondering if this is relevant because I think it could be interesting...
by Nick Lewis 4F
Sun Oct 20, 2019 11:01 pm
Forum: DeBroglie Equation
Topic: Linear Momentum
Replies: 6
Views: 62

Re: Linear Momentum

How does linear momentum relate to the De Broglie equation? I know the equation shows that wavelength = planck's constant / momentum, but what exactly does this mean? Does it just mean that an object with higher momentum will have a shorter wavelength? Cause it shows an inversely proportional relati...
by Nick Lewis 4F
Sun Oct 20, 2019 10:25 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Spin up and spin down
Replies: 13
Views: 111

Re: Spin up and spin down

Isn't spin up and spin down just relative? Couldn't it be that one electron spins to the left and one electron spins to the right? The only thing I am confused about is does this mean that the electrons are spinning in exactly 2 different directions? I'm just having trouble conceptualizing this conc...
by Nick Lewis 4F
Wed Oct 16, 2019 2:44 pm
Forum: Properties of Electrons
Topic: Question 1.15 on homework
Replies: 11
Views: 3925

Re: Question 1.15 on homework

I had a bit of trouble with this problem at first, but I looked at the problem on pg.7&8 in the textbook as an example. It goes from n1 and n2 to the wavelength of the emitted radiation. My only trouble in going back was how do we know n1=1? Otherwise it was easy to use the equations c = lambda ...
by Nick Lewis 4F
Sun Oct 13, 2019 10:48 pm
Forum: *Black Body Radiation
Topic: Black Body
Replies: 6
Views: 90

Re: Black Body

What would be an example of a black body? Is this something people produce out there? I think it sounds like a really interesting topic, but it doesn't sound like it is feasible to be made in real life.
by Nick Lewis 4F
Sun Oct 13, 2019 10:46 pm
Forum: *Shrodinger Equation
Topic: Schrodinger's Equation
Replies: 8
Views: 78

Re: Schrodinger's Equation

What is Schrodinger's equation? I understand what it does from that, but what is the difference in what this equation does from DeBroglies wave equation and Heisnebergs indeterminacy equation?
by Nick Lewis 4F
Sun Oct 13, 2019 10:44 pm
Forum: DeBroglie Equation
Topic: Diffraction
Replies: 4
Views: 41

Re: Diffraction

I understand what diffraction is, but I have trouble discerning the difference between constructive and destructive interference diffraction patterns. Can someone explain this better? I got a bit lost during lecture.
by Nick Lewis 4F
Sun Oct 13, 2019 10:41 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Best Way To Study?
Replies: 56
Views: 384

Re: Best Way To Study?

I think the best way to study is to jump right in. Attend peer review sessions/ office hours because just being around the material more will make you more familiar with it so you can understand it more. Another thing I think that is good to do is just practice. Do all the listed homework problems a...
by Nick Lewis 4F
Sun Oct 13, 2019 10:35 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student [ENDORSED]
Replies: 155
Views: 86409

Re: Advice from a Medical Student [ENDORSED]

Thank you for the insightful message! As a first year student, I don't really know what I want to do yet. I am a pre-biz Econ major, but I am kind of torn between an Econ route and a pre-med/pre-dent route. I am really enjoying this class so far because chemistry has always interested me. I am defin...
by Nick Lewis 4F
Fri Oct 04, 2019 11:07 am
Forum: Empirical & Molecular Formulas
Topic: Chapter F Problem 15
Replies: 4
Views: 60

Re: Chapter F Problem 15

Diazepam, a drug used to treat anxiety, has the mass percentage composition 67.49% C, 4.60% H, 12.45% Cl, 9.84% N, and 5.62% O. What is the empirical formula of the compound? I was wondering how we would calculate the molar mass of diazepam to solve for its empirical formula? Is this a common compo...
by Nick Lewis 4F
Fri Oct 04, 2019 11:03 am
Forum: SI Units, Unit Conversions
Topic: Help on Fundamentals: E21
Replies: 7
Views: 104

Re: Help on Fundamentals: E21

I'm pretty sure it's Avogadro's number regardless, since a mole of a substance indicates 6.022x10^23 atoms, molecules, or other chemical particles. Does this mean when a question asks for number of atoms, you can substitute atoms with molecules or particles as well? Are atoms/ molecules/ chemical p...
by Nick Lewis 4F
Fri Oct 04, 2019 10:58 am
Forum: Limiting Reactant Calculations
Topic: Homework Week 1
Replies: 18
Views: 203

Re: Homework Week 1

I think the homework was more straightforward this week than other weeks, but didn't Lavelle say that the homework is split up in topics? How would we know what problems to do for next week? On the syllabus it isn't split up by week so I am just a little confused...
by Nick Lewis 4F
Fri Oct 04, 2019 10:55 am
Forum: Significant Figures
Topic: Significant Figures
Replies: 6
Views: 54

Re: Significant Figures

I usually try to round off at the very end, but I feel like I still get answers off sometimes. Do you guys use the exact values in your calculator all the way through? I find this especially tricky to not round throughout the problem when you do limiting reactant/ stoichiometric calculations.
by Nick Lewis 4F
Fri Oct 04, 2019 10:51 am
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 169
Views: 103225

Re: Rusty on High School Chem [ENDORSED]

I can relate to all of the above because I took AP Chemistry when I was a junior in high school. It's hard to come back to it after a long time but do you guys have any more tips on how to jog your memory and become familiar with topics you used to know really well?

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