Search found 45 matches

by Sophia Kalanski 1A
Sun Nov 29, 2020 3:26 pm
Forum: Hybridization
Topic: delocalized pi bonds
Replies: 15
Views: 35

Re: delocalized pi bonds

delocalized pi bonds occur when there are resonance structures. If a pi bond can exist in a different region, then it is delocalized.
by Sophia Kalanski 1A
Sun Nov 29, 2020 3:25 pm
Forum: Hybridization
Topic: Sapling #20
Replies: 4
Views: 20

Re: Sapling #20

regardless of what type of bond it is, it will count as one electron density. A double bond will only count as one so there are in fact only 4 electron density regions and therefore it will have an sp3 hybridization
by Sophia Kalanski 1A
Sun Nov 29, 2020 3:23 pm
Forum: Hybridization
Topic: Hybridization for NH3
Replies: 1
Views: 21

Re: Hybridization for NH3

well the hybridization for NH3 would be sp3 because the nitrogen central atom has 3 bonded regions and one lone pair region (which is 4 different electron densities). When calculating the hybridization you want to first find that it is sp3 and then get more specific into finding which quantum number...
by Sophia Kalanski 1A
Sun Nov 29, 2020 3:17 pm
Forum: Hybridization
Topic: e density
Replies: 30
Views: 68

Re: e density

every bond and lone pair are seen as their own electron density yes, and on top of that a double bond would count as one electron density
by Sophia Kalanski 1A
Sun Nov 29, 2020 3:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Week 8 sapling #18
Replies: 3
Views: 14

Re: Week 8 sapling #18

I think that it's because it is written as H2CCCH2 instead of just C3H4. I believe that they were implying that the hydrogens will be connected only to the outer carbons.
by Sophia Kalanski 1A
Sun Nov 29, 2020 2:20 pm
Forum: Hybridization
Topic: sapling #11
Replies: 11
Views: 36

Re: sapling #11

It depends on the amount of electron regions there are attached to one atom. If there are 2 then it is an sp orbital since 1s is its own region and one p is another region. Double bonds count as one region.
by Sophia Kalanski 1A
Sun Nov 22, 2020 5:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pair position placing
Replies: 4
Views: 28

Re: lone pair position placing

Yes! These shapes exist because they are the ones that have the least amount of repulsion. For the square planar shapes, you want to make sure that the lone pairs are furthest away from each other and in that case, since only 4 of the 6 positions are occupied by bonded atoms, it will create a shape ...
by Sophia Kalanski 1A
Sun Nov 22, 2020 4:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle of Molecule
Replies: 7
Views: 40

Re: Bond Angle of Molecule

I think that its fine to list an answer that falls in the correct margin of the answer. In this case, since we knew that there were 4 bonds, and 2 of them were lone pairs, they would cause the angle between the lone pairs to be greater than 109.5 and the angles between the lone pairs and bonding pai...
by Sophia Kalanski 1A
Sun Nov 22, 2020 4:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pair E-
Replies: 47
Views: 154

Re: Lone Pair E-

yes they count as their own separate region and have a stronger repulsion power than the rest of the regions. the powers go from lone pair to lone pair>lone pair to bonding pair>bonding pair to bonding pair. This will in turn also cause the angles between the other regions to be greater.
by Sophia Kalanski 1A
Sun Nov 22, 2020 4:41 pm
Forum: Hybridization
Topic: Pi and Sigma Bonds
Replies: 10
Views: 55

Re: Pi and Sigma Bonds

I agree with the above statements, these sigma and pi bonds occur with any type of covalently bonded molecule since these molecules may consist of both double and triple bonds.
by Sophia Kalanski 1A
Sun Nov 22, 2020 4:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: shape
Replies: 6
Views: 26

Re: shape

Well I think its best to start with drawing out the lewis structure to figure out how many bonds are present and from there when you know that there are lone pairs or not, you can figure out approximately how far the angles would be from each pair of electrons that require the least repulsion effort...
by Sophia Kalanski 1A
Sun Nov 22, 2020 4:34 pm
Forum: Sigma & Pi Bonds
Topic: Sigma and Pi Bonds
Replies: 6
Views: 29

Re: Sigma and Pi Bonds

I don't believe that a double bond are called pi bonds since it contains both a sigma bond and a pi bond. I think that the thing you need to know though about double bonds is that since it has a pi bond, it is unable to rotate.
by Sophia Kalanski 1A
Sun Nov 15, 2020 10:39 pm
Forum: Bond Lengths & Energies
Topic: sapling #4
Replies: 3
Views: 28

Re: sapling #4

I agree with the above comment, when saying "ample" it is way more closer to the middle of the two bond lengths and therefore wont have significantly more than one or the other.
by Sophia Kalanski 1A
Sun Nov 15, 2020 10:37 pm
Forum: Resonance Structures
Topic: Sapling #4
Replies: 6
Views: 33

Re: Sapling #4

I would keep in mind that since there is delocalization of electrons, there could be many variations as to where you can include a double bond. The whole point is to find a resonance structure that has the least amount of individual formal charges among the atoms but still keeps the same overall for...
by Sophia Kalanski 1A
Sun Nov 15, 2020 10:35 pm
Forum: Lewis Structures
Topic: Sapling Week 5/6 HW #3
Replies: 7
Views: 34

Re: Sapling Week 5/6 HW #3

I doubt you would need to memorize it since we haven't learned how to formulate lewis structures or formulas based off names
by Sophia Kalanski 1A
Sun Nov 15, 2020 10:23 pm
Forum: Dipole Moments
Topic: H-Bond acceptor
Replies: 9
Views: 23

Re: H-Bond acceptor

No, the hydrogen needs to be attached to either F,N,O but the other atom just has to be electronegative.
by Sophia Kalanski 1A
Sun Nov 15, 2020 10:18 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Sapling #9 week 5/6
Replies: 13
Views: 45

Re: Sapling #9 week 5/6

In order to find the formal charge, you look at each atom within the molecule and find its formal charge. The resonance structure with the lowest amount of charges and changes will be the best one
by Sophia Kalanski 1A
Sun Nov 15, 2020 10:17 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Oxidation Number
Replies: 8
Views: 57

Re: Oxidation Number

It's just something you would need to know conceptually. Like for carbon, it would be a +4 because all the electrons move away from it to the more electronegative atom
by Sophia Kalanski 1A
Sun Nov 08, 2020 3:46 pm
Forum: Lewis Structures
Topic: Negative Sign
Replies: 12
Views: 49

Re: Negative Sign

The negative sign will be on the outside of the molecule and it is used to dictate the charge of the molecule based on how many electrons it will need to complete an octet and to be stable
by Sophia Kalanski 1A
Sun Nov 08, 2020 3:44 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge Equation
Replies: 16
Views: 65

Re: Formal Charge Equation

L represents the number of lone pairs and they can be counted in the lewis dot diagram
by Sophia Kalanski 1A
Sun Nov 08, 2020 3:39 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Sapling #2 weeks 5
Replies: 3
Views: 28

Re: Sapling #2 weeks 5

The way to draw this: you first start by making a single pair of each oxygen to the carbon. You notice that carbon still has a free electron that could bond with one of the oxygens to fill its octet, so it forms a double bond with one of the oxygen atoms which fills up the octet for that atom as wel...
by Sophia Kalanski 1A
Sun Nov 08, 2020 3:34 pm
Forum: Resonance Structures
Topic: Resonance & Stability
Replies: 4
Views: 31

Re: Resonance & Stability

to have several resonance structures allows for the electron density to be more evenly distributed and therefore the overall charge of the components in the molecule will be more neutral and therefore more stable.
by Sophia Kalanski 1A
Sun Nov 08, 2020 3:24 pm
Forum: Electronegativity
Topic: Electronegativity Table/Chart in Lecture
Replies: 14
Views: 48

Re: Electronegativity Table/Chart in Lecture

Hi! So I don't think we will have to know the exact value of the electronegativity of each element but we will need to know the general trends of electronegativity that occur in the periodic table and where electronegative atoms are found more.
by Sophia Kalanski 1A
Sun Nov 08, 2020 3:21 pm
Forum: Lewis Structures
Topic: Lewis Structure for BrF3
Replies: 6
Views: 25

Re: Lewis Structure for BrF3

I agree with everyone above, it must fill its octet and have 6 valence electrons. The book probably forgot to input the 2 electrons
by Sophia Kalanski 1A
Sat Oct 31, 2020 3:35 pm
Forum: Ionic & Covalent Bonds
Topic: lone pairs
Replies: 5
Views: 48

Re: lone pairs

yes! They usually are easier to lose or cause the atom to want to gain an electron to finish the orbital
by Sophia Kalanski 1A
Sat Oct 31, 2020 3:32 pm
Forum: Ionic & Covalent Bonds
Topic: Is ionic or covalent stronger?
Replies: 31
Views: 340

Re: Is ionic or covalent stronger?

ionic bonds are usually stronger because they are causing a transfer in electrons rather than a quick sharing of them. Covalent bonds are created by electronegativity and tend to be weaker
by Sophia Kalanski 1A
Sat Oct 31, 2020 3:29 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 10
Views: 163

Re: Electronegativity

typically electronegative atoms make covalent bonds and are non metal. It is more electronegative when it wants more electrons. For example, in H2O, Oxygen is very electronegative and that is why it bonds with 2 hydrogen atoms.
by Sophia Kalanski 1A
Sat Oct 31, 2020 3:27 pm
Forum: Lewis Structures
Topic: Lewis Structures
Replies: 7
Views: 196

Re: Lewis Structures

Use the atom with the lowest ionization energy (this is the least electromagnetic atom)
by Sophia Kalanski 1A
Sat Oct 31, 2020 3:24 pm
Forum: Ionic & Covalent Bonds
Topic: Inert vs Noble Gas
Replies: 4
Views: 31

Re: Inert vs Noble Gas

Hey! So im pretty sure both terms can be used interchangeably since noble gases are in the outermost level of the periodic table and don't partake in chemical reactions and inert gases are defined as not partaking in chemical reactions.
by Sophia Kalanski 1A
Sat Oct 31, 2020 3:16 pm
Forum: Octet Exceptions
Topic: Octet exception
Replies: 14
Views: 512

Re: Octet exception

H, He, Li, Be are not part of the octet rule because H and He only need to fill up an S orbital to satisfy the orbital and since Li and Be are closest to Helium, they will lost electrons to reach the amount of valence electrons/the state of helium and therefore they don't and won't have to fill an 8...
by Sophia Kalanski 1A
Fri Oct 23, 2020 2:18 am
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Light's effects
Replies: 8
Views: 95

Re: Light's effects

Hi! So I think that the electron is affected by the photon due to its size and mass. It was said during the lecture that a baseball wouldn't be affected because it is so big and therefore wouldn't feel the affects of the photon
by Sophia Kalanski 1A
Fri Oct 23, 2020 2:13 am
Forum: Properties of Electrons
Topic: Sapling 2 HW #6
Replies: 10
Views: 126

Re: Sapling 2 HW #6

Hi! So since it is excited to the n=6 level, it can return to any level below it (n=5,4,3,2,1) so it will have 5 different spectral lines.
To find the wavelength, we can use the rydberg formula to find the frequency and then, in turn you can use c=(wavelength)(frequency) to get the wavelength.
by Sophia Kalanski 1A
Fri Oct 23, 2020 12:04 am
Forum: Quantum Numbers and The H-Atom
Topic: Energy Levels
Replies: 8
Views: 75

Re: Energy Levels

Hi! So I think what he meant in his lecture was that the energy of the photon has to be atleast equal to/match the energy needed to move the electron up an energy level. It just can't be less than the needed energy to eject it.
by Sophia Kalanski 1A
Fri Oct 23, 2020 12:01 am
Forum: Photoelectric Effect
Topic: Sapling HW 2 Question 4
Replies: 6
Views: 81

Re: Sapling HW 2 Question 4

Hi! So in order to find the amount of electrons, you would need to divide the total energy (using the frequency and plank's constant) and then divide it by the work function because the work function is Jules per electron aka the energy needed to remove one electron. By doing this, you can find exac...
by Sophia Kalanski 1A
Thu Oct 22, 2020 11:53 pm
Forum: DeBroglie Equation
Topic: Rearranging De Broglie Equation
Replies: 17
Views: 106

Re: Rearranging De Broglie Equation

Hello!

So we know that the De Broglie Equation is originally (wavelength)=h/mv

to rearrange it so that you are trying to find the velocity, you would multiply v by both sides to cancel it out from the right side and then divide the wavelength by both sides.
You end up with v=h/(m*wavelength)
by Sophia Kalanski 1A
Fri Oct 16, 2020 5:23 pm
Forum: Einstein Equation
Topic: Einstein Equation
Replies: 10
Views: 217

Re: Einstein Equation

h stands for the plank constant and the v stands for the frequency. You can also, if you need to find the wavelength, use the frequency (v) and rewrite it as c/wavelength. This will get you E=hc/wavelength. C is the speed of light in the vacuum which is a constant and it is 3.00*10^8
by Sophia Kalanski 1A
Fri Oct 16, 2020 5:08 pm
Forum: Properties of Electrons
Topic: Rydberg's constant
Replies: 5
Views: 57

Re: Rydberg's constant

It depends on the measurements, the one that was shown in class was using S^-1 instead of M^-1
by Sophia Kalanski 1A
Fri Oct 16, 2020 5:05 pm
Forum: Photoelectric Effect
Topic: Excess energy
Replies: 20
Views: 110

Re: Excess energy

this equation is used to calculate the kinetic energy or the excess energy of the problem. In physics, that is the formula for kinetic energy
by Sophia Kalanski 1A
Fri Oct 16, 2020 4:54 pm
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 359

Re: m vs nm

I'm pretty sure it will specify what kind of SI units it will want, just know that NM is 10^-9 units.
by Sophia Kalanski 1A
Fri Oct 16, 2020 4:51 pm
Forum: Properties of Electrons
Topic: Lyman vs. Balmer series
Replies: 20
Views: 147

Re: Lyman vs. Balmer series

The difference between the Lymann series and the Balmer series is that the Lymann series displays which wavelengths/frequencies of UV light are shown in the H-atom that allow it to jump energy levels while the Balmer series is associated with visible light. The frequencies of the Lymann series are h...
by Sophia Kalanski 1A
Fri Oct 09, 2020 12:08 am
Forum: Limiting Reactant Calculations
Topic: Limiting reactants in all chemical rxns?
Replies: 18
Views: 130

Re: Limiting reactants in all chemical rxns?

Yes! There is always a limiting reactant because when dealing with different kinds of atoms, they are made up of different molar masses and moles so one of the reactants will always run out sooner than the other. This in turn, shows how much of the product will be produced.. the amount of limiting r...
by Sophia Kalanski 1A
Fri Oct 09, 2020 12:03 am
Forum: SI Units, Unit Conversions
Topic: Sig figs and molar mass
Replies: 18
Views: 93

Re: Sig figs and molar mass

I think its best to use the exact value as given to you on the periodic table to get the most accurate molar mass and then you should round it to how ever many sig figs necessary or as indicated in the end. You want to still make sure that your answer is as accurate as possible.
by Sophia Kalanski 1A
Thu Oct 08, 2020 11:29 pm
Forum: SI Units, Unit Conversions
Topic: #10 in the sapling
Replies: 6
Views: 82

Re: #10 in the sapling

Hi! I was lost on reading these too but I figured it out! Every corner is a carbon atom, and every line links it to another atom. The ones that end as like the last line still has a carbon atom at the end along with 3 hydrogen atoms to make each elemental atom complete its orbital (8 electrons). The...
by Sophia Kalanski 1A
Thu Oct 08, 2020 11:24 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 71
Views: 4413

Re: Step Up Sessions

For the step up sessions, are they done with our UAs and TAs? Would I just need to contact them personally or schedule them through the class website?
by Sophia Kalanski 1A
Thu Oct 08, 2020 11:12 pm
Forum: Limiting Reactant Calculations
Topic: Sapling Homework Question 10
Replies: 16
Views: 224

Re: Sapling Homework Question 10

Hi! I got to the part of the molecular formulas but I am having a hard time figuring out how to find the theoretical yield from the densities. Can someone help walk me through this? Thank you!

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