Search found 100 matches

by Madison Wong 3H
Mon Mar 01, 2021 10:10 am
Forum: Balancing Redox Reactions
Topic: adding H+ and H2O
Replies: 9
Views: 25

Re: adding H+ and H2O

For acidic solutions, add H+ to balance the H2O on the other side. For basic solutions, we must use OH- instead of H+, which often requires rebalancing of the hydrogen atoms.
by Madison Wong 3H
Mon Mar 01, 2021 10:09 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Reaction/Average Rate
Replies: 7
Views: 26

Re: Reaction/Average Rate

The average rate is the rate over the duration of the reaction, while the reaction rate is found at specific points. In Lavelle's lecture, the reaction rates were found through finding tangents to the curve, while the average rate was found using a slope technique over a longer period of time.
by Madison Wong 3H
Mon Mar 01, 2021 10:07 am
Forum: General Rate Laws
Topic: unique rate origin
Replies: 3
Views: 10

Re: unique rate origin

The unique rate relates the rates of change in concentration of the reactants and products within a reaction. Using aA-> bB +cC, -1/a(d[A]/dt) = 1/b(d[B]/dt) = 1/c(d[C]/dt) when taking into account the coefficients' relationship to rate of change.
by Madison Wong 3H
Mon Mar 01, 2021 10:05 am
Forum: Balancing Redox Reactions
Topic: Oxidizing Agent
Replies: 13
Views: 20

Re: Oxidizing Agent

As oxidizing agents are reduced themselves, the more likely it is to be reduced, the better it oxidizes. Higher reduction potentials suggest stronger oxidizing agents.
by Madison Wong 3H
Tue Feb 23, 2021 2:54 pm
Forum: Student Social/Study Group
Topic: Winter GEs?
Replies: 31
Views: 133

Re: Winter GEs?

Scand 50, Phil 22, and History 13b were all not too difficult and interesting!
by Madison Wong 3H
Tue Feb 23, 2021 2:53 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Exergonic Rxns
Replies: 14
Views: 26

Re: Exergonic Rxns

Yes, exergonic reactions have negative delta G and are thus spontaneous. Exergonic and exothermic are easily confused. Exothermic reactions are not always spontaneous.
by Madison Wong 3H
Tue Feb 23, 2021 2:52 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Molar Entropy
Replies: 10
Views: 22

Re: Molar Entropy

Molar entropy increases as an atom becomes more massive due to more possibilites for degeneracy and disorder within arrangement and positions.
by Madison Wong 3H
Tue Feb 23, 2021 2:51 pm
Forum: *Enzyme Kinetics
Topic: catalyst
Replies: 10
Views: 744

Re: catalyst

Catalysts and enzymes work by decreasing the activation energy by lowering the free energy of the transition state. Thus, the reaction has smaller required activation energy and progresses faster.
by Madison Wong 3H
Tue Feb 23, 2021 2:49 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Delta G and G naught
Replies: 37
Views: 100

Re: Delta G and G naught

Delta G naught is under standard conditions, while G can change as the reaction progresses.
by Madison Wong 3H
Mon Feb 15, 2021 6:13 pm
Forum: Administrative Questions and Class Announcements
Topic: Extra homework problems on Midterm 2
Replies: 14
Views: 141

Re: Extra homework problems on Midterm 2

The textbook problems related to midterm 2 material is under outline 3 and outline 4 of the syllabus posted on his website. Remember to exclude the questions that were covered on midterm 1 in the third outline.
by Madison Wong 3H
Mon Feb 15, 2021 6:11 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 2
Replies: 14
Views: 53

Re: Midterm 2

There are partial credit problems and also two extra credit problems!
by Madison Wong 3H
Mon Feb 15, 2021 6:11 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Cv and Cp on equation sheet
Replies: 1
Views: 12

Re: Cv and Cp on equation sheet

Yes, I believe since it isn't specified on the equations sheet it is just assumed to be the molar heat capacities and not specific heat capacities.
by Madison Wong 3H
Mon Feb 15, 2021 6:10 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: delta g equation- textbook problem 4J.17
Replies: 2
Views: 19

Re: delta g equation- textbook problem 4J.17

I'm not sure if there is an error posted in the solution manual, but I think the equation for change in free energy is generally delta G= delta h- T delta s.
by Madison Wong 3H
Mon Feb 15, 2021 6:09 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: confusion on using Cp and Cv
Replies: 22
Views: 85

Re: confusion on using Cp and Cv

Cp is the heat capacity at constant pressure, and Cv is the heat capacity at constant volume. They are related by the equation Cp = Cv + R.
by Madison Wong 3H
Mon Feb 08, 2021 12:51 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: isolated systems and constant energy
Replies: 6
Views: 28

Re: isolated systems and constant energy

Since change of internal energy is dependent on transfers of heat or work being done on the system, neither can occur within an isolated system, and thus, the internal energy change must be zero.
by Madison Wong 3H
Mon Feb 08, 2021 12:50 am
Forum: Student Social/Study Group
Topic: Study routine.
Replies: 51
Views: 112

Re: Study routine.

I usually try to go to UA sessions leading up to exams, but normally focus on reading through the textbook and doing textbook problems, as often there is one or two questions directly from the textbook on exams.
by Madison Wong 3H
Mon Feb 08, 2021 12:48 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm 2
Replies: 31
Views: 146

Re: Midterm 2

It will likely cover outline 3, 4, and possibly some of outline 5? im sure it will stop with material covered this week.
by Madison Wong 3H
Mon Feb 08, 2021 12:47 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Using R in thermodynamic equations
Replies: 24
Views: 86

Re: Using R in thermodynamic equations

For these problems, it is important to identify what units are given. Sometimes there are conversions involved, but generally you use the gas constant with the units (atm, Torr, J) that match up with what is given.
by Madison Wong 3H
Mon Feb 08, 2021 12:46 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeter Heat Capacity
Replies: 4
Views: 16

Re: Calorimeter Heat Capacity

Usually in calculating the heat capacity for the calorimeter, it is delta H divided by the change in temperature.
by Madison Wong 3H
Tue Feb 02, 2021 8:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Sectioning
Replies: 7
Views: 36

Re: Midterm Sectioning

Not sure about the amount of questions, but it will probably be similar to midterm 1 since it is still only 50 minutes. I think midterm 2 just covers material from week 4 to 7, but I'm sure he will release info later.
by Madison Wong 3H
Tue Feb 02, 2021 8:25 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: When work and heat should be positive/negative
Replies: 6
Views: 24

Re: When work and heat should be positive/negative

Heat is negative when the system loses heat and when the system itself does work. Heat is positive when the system absorbs heat due to work being done by its surroundings.
by Madison Wong 3H
Tue Feb 02, 2021 8:23 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calorimeters
Replies: 15
Views: 82

Re: Calorimeters

I think it would be generally helpful to make distinctions between types of calorimeters and how measurements from calorimeters can help in various calculations.
by Madison Wong 3H
Tue Feb 02, 2021 8:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Weeks 3 and 4 Sapling HW
Replies: 5
Views: 27

Re: Weeks 3 and 4 Sapling HW

The homework is due Sunday week 5, but I think the grade uploads to CClE automatically as you complete it.
by Madison Wong 3H
Tue Feb 02, 2021 8:19 pm
Forum: Student Social/Study Group
Topic: Spring 2021
Replies: 104
Views: 443

Re: Spring 2021

I will be taking 14c in spring!
by Madison Wong 3H
Mon Jan 25, 2021 9:12 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kw
Replies: 3
Views: 21

Re: Kw

Similarly, since water is neutral, the concentrations of H3O+ and OH- are equal, and in autoprotolysis of water, both concentrations are equal to 1x10^-7.
by Madison Wong 3H
Mon Jan 25, 2021 9:11 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE Chart Question
Replies: 16
Views: 86

Re: ICE Chart Question

You still include the coefficient in calculation for the equilibrium constant. I think this is because the ()^2 accounts for the coefficient in the equilibrium constant calculation while the -2x matters in relation to the molar ratios of other reactants and products.
by Madison Wong 3H
Mon Jan 25, 2021 9:09 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Textbook problem 6D.5
Replies: 3
Views: 21

Re: Textbook problem 6D.5

The kb values for these problems are either given in the basicicity constant table of the textbook or are derived from the Ka value, as it is a conjugate of this. To find Kb from Ka, you divide 10^-14 by the Ka.
by Madison Wong 3H
Mon Jan 25, 2021 9:07 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water
Replies: 7
Views: 19

Re: Water

Similar to amphoterism, water being amphiprotic suggests that it can act as both a proton donor or a proton acceptor.
by Madison Wong 3H
Mon Jan 25, 2021 9:06 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: endo/exothermic reactions
Replies: 13
Views: 32

Re: endo/exothermic reactions

It's easier for me to think about in terms of heating ice or heating liquid, it is breaking bonds to allow for particle movement. Atoms are most fluid in gases while in solids are largely locked.
by Madison Wong 3H
Wed Jan 20, 2021 12:10 pm
Forum: General Science Questions
Topic: Polyprotic Acids
Replies: 6
Views: 45

Re: Polyprotic Acids

Yes, Ka1 is the value deemed significant, as the second deprotonation is so small that it becomes insignificant when compared to the first.
by Madison Wong 3H
Mon Jan 18, 2021 1:57 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4D.3 Concept; Standard Rxn Enthalpies
Replies: 3
Views: 25

Re: 4D.3 Concept; Standard Rxn Enthalpies

It's helpful to consider heat as a reactant or product when considering the impact of changing temperature on a reaction. Whether it is endothermic or exothermic changes the direction of the reaction.
by Madison Wong 3H
Mon Jan 18, 2021 1:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Polyprotic Acids
Replies: 3
Views: 29

Re: Polyprotic Acids

I saw this in a textbook problem for the chemical equilibrium of acids and bases and was also confused.. The answer key seemed to suggest that the first deprotonation's concentrations are much larger than the second deprotonation, so you just focus on the first. I also want some clarification though.
by Madison Wong 3H
Mon Jan 18, 2021 1:54 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: midterms [ENDORSED]
Replies: 10
Views: 335

Re: midterms [ENDORSED]

alebenavides wrote:does anyone know what time the midterm is ?

The midterm is the same time as your lecture for the day. But it's still a 50 minute period.
by Madison Wong 3H
Mon Jan 18, 2021 1:53 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Moles vs Concentrations in ICE Box
Replies: 21
Views: 77

Re: Moles vs Concentrations in ICE Box

I use moles, because it makes it easier when writing it in the Ka equation to use molarity rather than moles as there is an extra step of considering volume that is missing.
by Madison Wong 3H
Mon Jan 18, 2021 1:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pKa
Replies: 4
Views: 27

Re: pKa

Since pKA is just the negative log base 10 of Ka, it helps to write out what the equation of Ka is: products over reactants. As stronger acids and bases dissociate more, creating more product, higher Ka values indicate stronger acids and bases. Once you take the negative log base 10, higher Ka value...
by Madison Wong 3H
Mon Jan 11, 2021 9:09 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Ba(OH)2 example
Replies: 8
Views: 70

Re: Ba(OH)2 example

since Ba(OH)2 is a strong base, it deprotonates and creates OH- instead of H3O+. Acidic substances would result in protonation and thus production of H3O+.
by Madison Wong 3H
Mon Jan 11, 2021 9:08 pm
Forum: Student Social/Study Group
Topic: Midterms?
Replies: 14
Views: 144

Re: Midterms?

the first midterm is january 29 during your lecture time, but it's still 50 minutes. Before it was discussions, but now everyone takes it on the same day during their lecture time.
by Madison Wong 3H
Mon Jan 11, 2021 9:05 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Water in Excess
Replies: 7
Views: 51

Re: Water in Excess

In one of the modules, Lavelle mentioned that solids and liquids (including water) are not included in finding K constants, and sometimes water isn't even written into equations because it is often present in excess.
by Madison Wong 3H
Mon Jan 11, 2021 9:04 pm
Forum: Student Social/Study Group
Topic: Favorite TV shows
Replies: 189
Views: 1226

Re: Favorite TV shows

I'd recommend Ink Master as background and The undoing on HBO for a bit more focused murder mystery vibes
by Madison Wong 3H
Mon Jan 11, 2021 9:03 pm
Forum: Student Social/Study Group
Topic: Comfort Movies
Replies: 128
Views: 357

Re: Comfort Movies

Robots and aquamarine!
by Madison Wong 3H
Mon Jan 04, 2021 12:57 pm
Forum: Administrative Questions and Class Announcements
Topic: 14B Discussion Sections
Replies: 4
Views: 63

Re: 14B Discussion Sections

I was wondering the same thing, mine doesn't show up on CCLE either.
by Madison Wong 3H
Mon Jan 04, 2021 12:40 pm
Forum: Ideal Gases
Topic: Converting to Concentration and Pressure Values
Replies: 7
Views: 69

Converting to Concentration and Pressure Values

I'm a bit confused on how we use the ideal gas law to convert between the pressures of gas and concentrations of gas. What do all of the constants in Pv=nRT stand for?
by Madison Wong 3H
Mon Jan 04, 2021 12:27 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Posts in 14B
Replies: 156
Views: 2389

Re: Chemistry Posts in 14B

I think we keep our accounts, but update your username to reflect your new discussion section. It saves all your posts.
by Madison Wong 3H
Mon Jan 04, 2021 12:00 pm
Forum: Administrative Questions and Class Announcements
Topic: Chem Community Username
Replies: 10
Views: 67

Chem Community Username

Do we have to change our username to our new discussion section in order to get points for chem community? If so, how?
by Madison Wong 3H
Tue Dec 08, 2020 7:20 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted vs Lewis
Replies: 8
Views: 59

Re: Bronsted vs Lewis

Lewis focuses on electrons while Bronsted focuses on protons
by Madison Wong 3H
Tue Dec 08, 2020 7:19 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate ligands and coordination number
Replies: 2
Views: 42

Re: Polydentate ligands and coordination number

Polydentate ligands are ligands that bond in more than one area, as opposed to a monodentate ligand. For polydentate ligands, to find the coordination number it is the same process, just paying attention to how many bonds each polydentate ligand can make. ethylenediamine for example is a bidentate, ...
by Madison Wong 3H
Tue Dec 08, 2020 7:16 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Why do we need this?
Replies: 5
Views: 102

Re: Why do we need this?

I think the heisenberg uncertainty principle reinforces the idea that the measurement process influences the outcome. With the example that Lavelle gave of the measurement of an electron passing through motion detectors, it shows that photons scattered from an electron within measurement with affect...
by Madison Wong 3H
Tue Dec 08, 2020 7:14 pm
Forum: Identifying Acidic & Basic Salts
Topic: NH4Cl Salt- Spectator Ions
Replies: 3
Views: 34

Re: NH4Cl Salt- Spectator Ions

I think it has something to do with Chlorine not reacting with water, and thus it won't make a substance more acidic or basic by donating or accepting protons.
by Madison Wong 3H
Tue Dec 08, 2020 7:12 pm
Forum: Conjugate Acids & Bases
Topic: Amphoteric
Replies: 11
Views: 103

Re: Amphoteric

Amphoteric substances can act as either acids or bases, I think lavelle also said that the amphoteric substances often align with the diagonal band of metalloids, but that it doesn't match up perfectly.
by Madison Wong 3H
Mon Nov 30, 2020 8:31 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Textbook 2F 15
Replies: 2
Views: 31

Textbook 2F 15

Noting that the bond angle of an sp3 hybridized atom is 109.5° and that of an sp2 hybridized atom is 120°, do you expect the bond angle between two hybrid orbitals to increase or decrease as the s-character of the hybrids is increased?
by Madison Wong 3H
Mon Nov 30, 2020 7:12 pm
Forum: Student Social/Study Group
Topic: Molecule Modeling tool
Replies: 4
Views: 40

Re: Molecule Modeling tool

Thanks so much!
by Madison Wong 3H
Mon Nov 30, 2020 7:11 pm
Forum: Hybridization
Topic: How to simply determine hybridization
Replies: 27
Views: 217

Re: How to simply determine hybridization

I just count the regions of electron density and find the corresponding number. sp would be two areas, sp2 would be three areas, sp3 would be four areas, etc .
by Madison Wong 3H
Mon Nov 30, 2020 7:09 pm
Forum: Hybridization
Topic: Delocalized Pi Bond
Replies: 10
Views: 93

Re: Delocalized Pi Bond

A delocalized pi bond is similar to the concept of delocalized electrons that occur within resonance structures. When a molecule has different resonant structures, the pi bond can be blended to different areas.
by Madison Wong 3H
Mon Nov 30, 2020 7:07 pm
Forum: Hybridization
Topic: Why do double bonds (and triple bonds) count as one region of electron density?
Replies: 8
Views: 87

Re: Why do double bonds (and triple bonds) count as one region of electron density?

I think when considering regions of electron density, the type of bond doesn't matter, as there is electron density regardless if it is a lone pair, single bond, double bond, etc.
by Madison Wong 3H
Mon Nov 30, 2020 7:04 pm
Forum: Hybridization
Topic: sp^3
Replies: 8
Views: 88

Re: sp^3

I think it was especially common because sp3 is the hybridization for carbon, and tetrahedrals as it suggests four regions of electron density
by Madison Wong 3H
Mon Nov 23, 2020 10:58 pm
Forum: Hybridization
Topic: Carbon double bond
Replies: 3
Views: 39

Re: Carbon double bond

I think since the pi bonds are overlapping side by side and have rigid geometry, the bonds can't rotate and thus are all on the same plane.
by Madison Wong 3H
Mon Nov 23, 2020 10:57 pm
Forum: Hybridization
Topic: Hybridization Application
Replies: 2
Views: 24

Re: Hybridization Application

Hybridization is also related to the regions of electron density, since the regions of electron density is equal to the number of hybrid orbitals.
by Madison Wong 3H
Mon Nov 23, 2020 10:55 pm
Forum: Hybridization
Topic: e density
Replies: 30
Views: 173

Re: e density

Yes, you consider lone pairs and bonding pairs as regions of electron density. You only count double and triple bonds as one region however, because you're only considering the regions of electron density not the bond types themselves.
by Madison Wong 3H
Mon Nov 23, 2020 10:53 pm
Forum: DeBroglie Equation
Topic: De broglie equation versus E=hv
Replies: 9
Views: 141

Re: De broglie equation versus E=hv

An easy way I remember is that particles with mass cannot be traveling at the speed of light, so you can only use the debroglie equation when considering photons and particles without mass.
by Madison Wong 3H
Mon Nov 23, 2020 10:50 pm
Forum: Octet Exceptions
Topic: Octect expansion and hybridized orbitals
Replies: 3
Views: 38

Re: Octect expansion and hybridized orbitals

I think so, in his lecture from today he suggested that expanded octets would be in the dsp3 or d2sp3 hybridizations.
by Madison Wong 3H
Mon Nov 23, 2020 10:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: memorization
Replies: 12
Views: 144

Re: memorization

I use this as a reference for VSEPR and the shape/bond angles. Hope this helps!
https://ds055uzetaobb.cloudfront.net/im ... 091b2c.png
by Madison Wong 3H
Mon Nov 16, 2020 6:33 pm
Forum: Student Social/Study Group
Topic: Favorite TV shows
Replies: 189
Views: 1226

Re: Favorite TV shows

I recommend Community if you want an alternative to parks and rec or the office!
by Madison Wong 3H
Mon Nov 16, 2020 6:32 pm
Forum: Student Social/Study Group
Topic: Midterm 2 content
Replies: 20
Views: 178

Re: Midterm 2 content

I think just formal charge and maybe the equation for potential energy in london dispersion forces which involves the polarizability of the two molecules divided by the distance between them^6.
by Madison Wong 3H
Mon Nov 16, 2020 6:28 pm
Forum: Lewis Structures
Topic: 2C.5
Replies: 3
Views: 41

Re: 2C.5

I think it has to do with formal charge, but it could also depend on electronegativity.
by Madison Wong 3H
Mon Nov 16, 2020 6:25 pm
Forum: Bond Lengths & Energies
Topic: Boiling Point of Molecules
Replies: 2
Views: 31

Re: Boiling Point of Molecules

I think that for intermolecular, and in particular the london forces for induced dipoles are dependent on polarizability for the potential energy. Since larger atoms have electrons that are farther from the nucleus or less tightly held they are more polarizable and thus have stronger london bonds.
by Madison Wong 3H
Mon Nov 16, 2020 6:22 pm
Forum: Student Social/Study Group
Topic: Studying for Midterm 2
Replies: 4
Views: 30

Re: Studying for Midterm 2

The UA sessions are really helpful, in one of the linked groupme's there is a google drive with shared worksheets from the sessions if you want to access them!
by Madison Wong 3H
Mon Nov 09, 2020 9:49 am
Forum: Student Social/Study Group
Topic: Midterm 2 Study Group
Replies: 25
Views: 167

Re: Midterm 2 Study Group

awesome!
by Madison Wong 3H
Mon Nov 09, 2020 9:48 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm 1 answer key
Replies: 13
Views: 109

Re: Midterm 1 answer key

I think if you email your TA they can tell you which problems you got wrong and which you received partial credit for!
by Madison Wong 3H
Mon Nov 09, 2020 9:47 am
Forum: Ionic & Covalent Bonds
Topic: Sulfate
Replies: 8
Views: 33

Re: Sulfate

I'm not positive, but basing it on quantum numbers, I think atoms in the d block have quantum number l=2 and thus can have 10 electrons since Ml can be 2,1,0,-1,-2 and 2 electrons can accompany each of those, which would be an expanded octet. I'm still a bit confused myself though.
by Madison Wong 3H
Mon Nov 09, 2020 9:44 am
Forum: Ionic & Covalent Bonds
Topic: 2C.11
Replies: 2
Views: 15

Re: 2C.11

In order to have the most stable molecule, with the least energy you use a double bond to have the formal charge of -1 for O and 1 for Xe, leading to a stable molecule with low energy.
by Madison Wong 3H
Mon Nov 09, 2020 9:42 am
Forum: Lewis Structures
Topic: Middle Atom
Replies: 4
Views: 19

Re: Middle Atom

The central atom should be the least electronegative atom. A TA also suggested that somethings Lavelle will place the central atom in the middle of the molecular compound, for example in ClCCn, C is the central atom. But in general just pay attention to the electronegativity.
by Madison Wong 3H
Mon Nov 09, 2020 9:40 am
Forum: Lewis Structures
Topic: Placement of central atom
Replies: 5
Views: 21

Re: Placement of central atom

Hi!
in the same way you put the most electronegative atom in the center, you also choose resonant structures that don't place charge on the central atom as it is the least electronegative.
by Madison Wong 3H
Mon Nov 02, 2020 1:41 pm
Forum: SI Units, Unit Conversions
Topic: Converting equations
Replies: 14
Views: 157

Re: Converting equations

Also make sure that you place parentheses in the right places when combining multiple steps of an equation, to make sure there aren't PEMDAS issues that could result in a wrong answer!
by Madison Wong 3H
Mon Nov 02, 2020 1:39 pm
Forum: Lewis Structures
Topic: Different Lewis Structures
Replies: 6
Views: 55

Re: Different Lewis Structures

I'm pretty sure they are still considered resonant, as his definition was structures with the same arrangement of atoms, but different arrangement of electrons, so even mirror images would be considered different and resonant.
by Madison Wong 3H
Mon Nov 02, 2020 1:35 pm
Forum: Student Social/Study Group
Topic: Midterm 2
Replies: 31
Views: 327

Re: Midterm 2

I think so, along with the new material that we're learning now! He will probably post another outline of covered topics for midterm 2.
by Madison Wong 3H
Mon Nov 02, 2020 1:33 pm
Forum: General Science Questions
Topic: # of spectral lines
Replies: 3
Views: 45

Re: # of spectral lines

The number of spectral lines that appears is n-1, so 5-1, and thus four spectral lines. Hope this helps!
by Madison Wong 3H
Mon Nov 02, 2020 1:32 pm
Forum: Lewis Structures
Topic: Lecture #14: SO4^2- Lewis Structure
Replies: 5
Views: 47

Re: Lecture #14: SO4^2- Lewis Structure

I know that it has something with being in the third period of the periodic table and thus part of the d block, which can have more bonds. I think there is a more in depth way of explaining but this is what he mentioned quickly during the lecture.
by Madison Wong 3H
Mon Oct 26, 2020 2:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 1 information
Replies: 7
Views: 126

Re: Midterm 1 information

1) The midterm is during your discussion. 2) This is different depending on your TA, but for mine I can use my phone for zoom positioned towards my work space, and use my computer for taking the test itself. I would ask your TA to make sure what their policy is. 3) Multiple choice, it hasn't been co...
by Madison Wong 3H
Mon Oct 26, 2020 2:56 pm
Forum: Administrative Questions and Class Announcements
Topic: sapling questions for midterm prep
Replies: 2
Views: 45

sapling questions for midterm prep

Since we aren't able to un randomize our questions for sapling, does anyone know the questions that cover topics that will be included on the midterm? Thank you
by Madison Wong 3H
Mon Oct 26, 2020 2:43 pm
Forum: DeBroglie Equation
Topic: Deriving the DeBroglie Equation
Replies: 4
Views: 46

Re: Deriving the DeBroglie Equation

I think just knowing the general concept, he derived it during lecture it has to do with the equation E=mc^2 and E=H(frequency). You equate them both and then change the speed of light for velocity.
by Madison Wong 3H
Mon Oct 26, 2020 2:41 pm
Forum: Quantum Numbers and The H-Atom
Topic: Px Py Pz
Replies: 4
Views: 35

Px Py Pz

During Lavelle's lecture on Friday, he kept referring to Px, Py, Pz and other x,y,z orbitals. I was confused on how he determines this, and what the symbols mean. Thanks!
by Madison Wong 3H
Mon Oct 26, 2020 2:38 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Spectral Lines
Replies: 2
Views: 30

Re: Spectral Lines

In general, the amount of spectral lines is n-1.
by Madison Wong 3H
Tue Oct 20, 2020 8:01 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Sapling Q8
Replies: 1
Views: 14

Sapling Q8

Hi, if anyone could help me with this problem, its 8 on the sapling assignment! A violet line is observed at 434.0 nm in the spectrum of atomic hydrogen. Determine the values of n for the beginning and ending energy levels of the electron during the emission of energy that leads to this spectral line.
by Madison Wong 3H
Tue Oct 20, 2020 6:20 pm
Forum: Photoelectric Effect
Topic: Intensity Proportional to Number of Photons?
Replies: 4
Views: 38

Re: Intensity Proportional to Number of Photons?

I was a bit confused on this too. Does increasing the number of photons increase the energy, or does it not affect the energy since changing the intensity of light didn't result in more emitted electrons?
by Madison Wong 3H
Tue Oct 20, 2020 6:10 pm
Forum: Properties of Electrons
Topic: Wave properties of electrons and diffraction
Replies: 3
Views: 26

Re: Wave properties of electrons and diffraction

Yes, I think diffraction also has to do with the interference of waves- constructive and destructively. From the interaction of waves comes the same properties of waves from electrons, which encourages the idea of electrons having particle like and wavelike qualities!
by Madison Wong 3H
Tue Oct 20, 2020 6:07 pm
Forum: Properties of Light
Topic: Midterm
Replies: 42
Views: 390

Re: Midterm

It's not open note, it's multiple choice, and not curved. Apparently some questions are weighted more heavily than others. I'm still not sure about partial credit.
by Madison Wong 3H
Tue Oct 20, 2020 6:01 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Saping HW Q.8
Replies: 8
Views: 78

Re: Saping HW Q.8

How do we know that n1=2? Is it characteristic of visible light in general or did it require solving?
by Madison Wong 3H
Tue Oct 20, 2020 5:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Where can I buy a webcam for a reasonable price?
Replies: 60
Views: 1181

Re: Where can I buy a webcam for a reasonable price?

I just got one off amazon for 15$ with free shipping before my discussion next week!
by Madison Wong 3H
Wed Oct 14, 2020 11:10 am
Forum: Significant Figures
Topic: Sig Fig Process
Replies: 13
Views: 112

Re: Sig Fig Process

I usually just use all the saved values in my calculator and don't round anything until the last step, I think this helps in multi-step problems!
by Madison Wong 3H
Wed Oct 14, 2020 11:08 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Lecture question
Replies: 5
Views: 51

Re: Atomic Spectra Lecture question

I think so but I'm not positive.. I think this relates to the emission spectrum for each element being like a fingerprint of every element and each element absorbs and emits light differently.
by Madison Wong 3H
Wed Oct 14, 2020 11:06 am
Forum: Properties of Electrons
Topic: Electrons Excited or Ejected
Replies: 19
Views: 145

Electrons Excited or Ejected

I'm confused on the difference between electrons being ejected and excited.. What is the difference?
by Madison Wong 3H
Wed Oct 14, 2020 11:00 am
Forum: Properties of Light
Topic: Light intensity for electron ejection
Replies: 7
Views: 65

Re: Light intensity for electron ejection

I think multiple electrons are ejected, but each photon must have enough energy to eject each electron. Since there are multiple photons within the light it results in multiple electrons ejected.
by Madison Wong 3H
Mon Oct 12, 2020 7:17 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: 1A Book Problem 15
Replies: 2
Views: 29

1A Book Problem 15

Hi, if anyone could explain the work for this question
"In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the values of n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral line."
by Madison Wong 3H
Tue Oct 06, 2020 4:47 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Q29 Atomic Spectra Postmodule
Replies: 3
Views: 33

Q29 Atomic Spectra Postmodule

29. In 1.0 s, a 60 W bulb emits 11 J of energy in the form of infrared radiation (heat) of wavelength 1850 nm. What is the energy per photon of light emitted?
How many photons of infrared radiation does the lamp generate in 1.0 s?
by Madison Wong 3H
Tue Oct 06, 2020 2:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Office Hours and other Sessions [ENDORSED]
Replies: 4
Views: 150

Re: Office Hours and other Sessions [ENDORSED]

Lavelle said it's fine if you drop in at any point and just listen in, doesn't seem like we need to have any questions prepared! I think it's the same with his step up sessions and UA sessions.
by Madison Wong 3H
Tue Oct 06, 2020 2:19 pm
Forum: Limiting Reactant Calculations
Topic: Limiting Reactants Help M11?
Replies: 3
Views: 23

Re: Limiting Reactants Help M11?

I think the work to this one was posted earlier on chemistry community, just copy and paste the problem!
by Madison Wong 3H
Mon Oct 05, 2020 3:38 pm
Forum: Administrative Questions and Class Announcements
Topic: Submitting HW on Sapling
Replies: 5
Views: 62

Re: Submitting HW on Sapling

I think as long as you've completed each problem you get full credit for the homework assignment!
by Madison Wong 3H
Mon Oct 05, 2020 12:41 pm
Forum: Balancing Chemical Reactions
Topic: Combustion
Replies: 14
Views: 196

Re: Combustion

I think it also has something to do with oxygen as one of the reactants for oxidation and combustion

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