Search found 52 matches

by tamara masri_3D
Sat Dec 12, 2020 10:20 pm
Forum: Hybridization
Topic: Hybridization of CO2
Replies: 5
Views: 45

Re: Hybridization of CO2

That looks right to me!
by tamara masri_3D
Sat Dec 12, 2020 9:36 pm
Forum: Properties of Electrons
Topic: atomic spectra
Replies: 2
Views: 21

Re: atomic spectra

I believe n=1 refers to the ground state so the first excited state would be n=2
by tamara masri_3D
Sat Dec 12, 2020 9:35 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Square planar complex vs tetrahedral complex
Replies: 6
Views: 51

Re: Square planar complex vs tetrahedral complex

I'm not 1000% sure how it relates to ligands, but I know that square planar shape generally occurs when there are 2 lateral lone pairs and 4 equatorial bonding pairs for an atom. This would be an octahedral electron geometry but with 2 lone pairs. Tetrahedral geometry occurs when there are 4 regions...
by tamara masri_3D
Sat Dec 12, 2020 9:30 pm
Forum: Naming
Topic: K[Cu(en)2 (CN)2 ]
Replies: 7
Views: 60

Re: K[Cu(en)2 (CN)2 ]

This would have to do with it being bonded to the K+, which "cancels out" the second negative charge from the CN-
by tamara masri_3D
Sat Dec 12, 2020 9:22 pm
Forum: Naming
Topic: [Ni(NH3)2O2]Br2
Replies: 3
Views: 35

Re: [Ni(NH3)2O2]Br2

Hi! I'm not sure what the answer key says but I'm pretty sure that the oxidation number of Ni is 6+. You can solve for this by looking at the fact that NH3 is neutral, so that won't affect it. Next, we see that there are 2 O atoms attached and we know that O has an oxidation state of -2, multiplied ...
by tamara masri_3D
Sat Dec 12, 2020 9:10 pm
Forum: Coordinate Covalent Bonds
Topic: cisplatin
Replies: 1
Views: 21

Re: cisplatin

I understood that cisplatin binds to N7 (a nitrogen with a lone pair) and based on this I would assume that there would need to be 2 guanines next to each other for it to work properly, though I am not completely sure.
by tamara masri_3D
Sat Dec 12, 2020 9:05 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to Determine if a Ligand is polydentate?
Replies: 6
Views: 82

Re: How to Determine if a Ligand is polydentate?

Hey! Sorry for the late reply but from what I understood, yes, though I think there are some specific exceptions mentioned in lecture that I think Dr. Lavelle said we don't have to have memorized. Hi! Thank you for your further clarification on ligands. Going off of H2O, because the two lone pairs a...
by tamara masri_3D
Fri Dec 04, 2020 5:54 pm
Forum: Hybridization
Topic: Hybridization(2F.17)
Replies: 1
Views: 18

Re: Hybridization(2F.17)

Hello! In this case, the orbitals responsible for the bonds between c and o are the only ones that can be hybridized. H has only 1 electron in the 1s orbital so you can't exactly have an sp hybridization of any kind. Hope this helps!
by tamara masri_3D
Fri Dec 04, 2020 5:50 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Sapling Question 2
Replies: 3
Views: 40

Re: Sapling Question 2

Hi! The coordination number is the number of bonds formed by the metal. it's important to remember that most (if not all) of the ligands in this problem are monodentate so it wouldn't exactly be the subscripts in the brackets, but the number of ligands bonding to one metal molecule (for polydentate ...
by tamara masri_3D
Fri Dec 04, 2020 5:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: chelate
Replies: 7
Views: 55

Re: chelate

yes! If you recall from Professor Lavelle's previous lectures, sigma bonds are flexible in the sense that they can rotate. Therefore, if there were pi bonds involved in the ligand structure, it is not very likely that they will be chelates. Hope this helps!
by tamara masri_3D
Fri Dec 04, 2020 5:41 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to Determine if a Ligand is polydentate?
Replies: 6
Views: 82

Re: How to Determine if a Ligand is polydentate?

Hello! Going off of what Thomas said, when you draw the lewis structure of the compound and see that there are multiple atoms that can potentially donate their lone pairs to be ligands, you need to remember that e-e repulsion still plays a huge role. For example, if you had an O atom that has 2 lone...
by tamara masri_3D
Fri Dec 04, 2020 5:26 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Calculations involving strong acids
Replies: 3
Views: 34

Re: Calculations involving strong acids

Hello! In this case, it is important to remember that M is equal to mol/L, not just mol. Therefore, you're not actually creating 0.2 mol of HCl solution in water. Instead, this is saying that the 0.1 mol/L of HCl is the same as the 0.1 mol/L of H+ and Cl-. M is a measure of concentration, not mass. ...
by tamara masri_3D
Fri Nov 27, 2020 2:18 pm
Forum: Sigma & Pi Bonds
Topic: Main Difference between Sigma & Pi Bonds Q
Replies: 4
Views: 42

Re: Main Difference between Sigma & Pi Bonds Q

Hello! To start, both bonds are formed when orbitals overlap. The difference between sigma bonds and pi bonds is that sigma bonds overlap head-on (imagine teardrop-shaped sp hybridized orbitals overlapping at the base of the teardrop shape). On the other hand, pi bonds form when the orbitals overlap...
by tamara masri_3D
Fri Nov 27, 2020 1:55 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: coordinate covalent bond angle
Replies: 1
Views: 52

Re: coordinate covalent bond angle

Hello! This is a great observation but I think it wouldn't make too big of a difference because although the bonding pair might have less of an e-e repulsion, you now have to deal with the repulsion from the electron cloud surrounding the atom bonding to the Cl. Hope this helps!
by tamara masri_3D
Fri Nov 27, 2020 12:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: sigma bonds and single bonds
Replies: 5
Views: 27

Re: sigma bonds and single bonds

hello! In the case of ethene, you have 2 carbons with a double bond between them. Each also has 2 hydrogens single-bonded to them. So, the single bonds are sigma bonds. However, the double bond is comprised of both a sigma and a pi bond. If I understand your question correctly, yes, single bonds are...
by tamara masri_3D
Fri Nov 27, 2020 12:27 pm
Forum: Hybridization
Topic: unhybridized p orbital
Replies: 2
Views: 15

Re: unhybridized p orbital

Hello! I think I understand what you're asking, though I apologize if this doesn't answer your question. When you hybridize s and p orbitals, you essentially combine the shapes. A sp hybrid orbital is not exactly a sphere shape like a s orbital, nor is it exactly a dumbell shape like a p orbital. Ra...
by tamara masri_3D
Fri Nov 27, 2020 12:21 pm
Forum: Hybridization
Topic: 2sp^2 vs 3sp^2
Replies: 6
Views: 47

Re: 2sp^2 vs 3sp^2

Hello! Yes you would, since 3s and 3p are the orbitals being hybridized in that case.
by tamara masri_3D
Sat Nov 21, 2020 1:47 pm
Forum: Sigma & Pi Bonds
Topic: Sigma and Pi bonds relating to resonance
Replies: 2
Views: 33

Re: Sigma and Pi bonds relating to resonance

Hello! I'm pretty sure Dr. Lavelle told us that we don't need to worry about drawing the molecules in this course, so don't worry too much about it. However, we also learned that in real molecules that display resonance, the bonds are all the same length and are basically a combination of s and p or...
by tamara masri_3D
Fri Nov 20, 2020 5:06 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw Shape Bond Angles
Replies: 2
Views: 12

Re: Seesaw Shape Bond Angles

Hello! Although the drawings make it look like it's exactly 180 and 120, I think it's safe to say that in the seesaw shape, the bond angles would be less than that. We learned that the lone pair have a greater "push" to distort the bond angles and that in the trigonal pyramidal shape, the ...
by tamara masri_3D
Fri Nov 20, 2020 2:52 pm
Forum: Hybridization
Topic: Mixing orbitals
Replies: 2
Views: 32

Re: Mixing orbitals

Hi! The example Dr. Lavelle showed us was with carbon, where, while the s orbital was full, the p orbital had 2 unpaired electrons and 2 completely empty orbitals. What I understood was that since we know that carbon can make 4 bonds (from experimental data and lewis diagrams) we know that something...
by tamara masri_3D
Fri Nov 20, 2020 2:45 pm
Forum: Sigma & Pi Bonds
Topic: Hybridization
Replies: 7
Views: 91

Re: Hybridization

Yes. For example instead of having separate s and p orbitals, hybridization combines them so that you have 4 identical orbitals that are kind of a combination of both s and p orbitals, with an energy not as low as s, but not as high as p.
by tamara masri_3D
Fri Nov 20, 2020 2:41 pm
Forum: Sigma & Pi Bonds
Topic: Sigma Bonds in Double Bonds
Replies: 2
Views: 54

Re: Sigma Bonds in Double Bonds

From my understanding, yes. We learned that bond length has a lot to do with the number of bonds, but in terms of sigma bonds, or single bonds, the atoms are definitely closer to each other when the bonds are formed vs when there is no bond between them. Building off of that, the more bonds there ar...
by tamara masri_3D
Fri Nov 13, 2020 4:44 pm
Forum: Lewis Structures
Topic: Chemical Names
Replies: 9
Views: 62

Re: Chemical Names

Since we haven't gone over nomenclature yet, I would assume that we don't have to know that. But I'm not 100% sure
by tamara masri_3D
Fri Nov 13, 2020 4:42 pm
Forum: Electronegativity
Topic: Electronegativity: O v. Cl
Replies: 3
Views: 16

Re: Electronegativity: O v. Cl

hello! I'm pretty sure that the vertical change in the periodic table would have a bigger affect on the electronegativity because there would be more distance between the electrons and the nucleus and there would also be more e-e "shadowing" (I can't think of the exact name for it sorry). ...
by tamara masri_3D
Fri Nov 13, 2020 4:31 pm
Forum: Lewis Structures
Topic: 2C. 3 Textbook problem
Replies: 1
Views: 20

Re: 2C. 3 Textbook problem

Hello! Oxygen can make 2 bonds, and wants to have a complete octet so hydrogen provides that for it. Therefore, it would be more favorable to bond to O than it would be to bond to the other atoms
by tamara masri_3D
Fri Nov 13, 2020 4:00 pm
Forum: Dipole Moments
Topic: Fluctuating electron density
Replies: 2
Views: 14

Re: Fluctuating electron density

Hello! Building off of Isabelle's answer, I think it's also important to recognize the electrostatic force that plays a large part in determining how an electron will behave. For example, electrons are more likely to congregate around the positively charged nucleus as they are attracted to it. On th...
by tamara masri_3D
Fri Nov 13, 2020 3:53 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic/Covalent characters
Replies: 2
Views: 7

Re: Ionic/Covalent characters

hello! So ionic characteristics arise when there is a greater charge separation between the atoms. Covalent characteristics are more prevalent in cases where electrons are shared between atoms. In many cases, there is no true ionic or covalent bond, since each one has some characteristics of the oth...
by tamara masri_3D
Fri Nov 06, 2020 11:39 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Isoelectric atoms
Replies: 9
Views: 38

Re: Isoelectric atoms

Hello! Isoelectronic means same number of electrons. This refers to different atoms (ex. Na+, Mg2+, F-, O2-, Ne) that have the same number of electrons. Although the number of electrons is the same, they have different properties. For example, atoms that lose electrons (Na+, Mg2+) are smaller and ha...
by tamara masri_3D
Fri Nov 06, 2020 11:27 pm
Forum: Lewis Structures
Topic: Using sapling to draw lewis structures
Replies: 3
Views: 20

Re: Using sapling to draw lewis structures

I think the best way to really understand is to experiment with it a but haha. From what I learned, you click in the "draw" tab to add the atoms and bonds. Click on the atom you want to add, then click in the white space below to "place" it. Next, you can click on either the doub...
by tamara masri_3D
Fri Nov 06, 2020 11:20 pm
Forum: Lewis Structures
Topic: lewis structure
Replies: 17
Views: 49

Re: lewis structure

Hello! The bracket with the charge on the outside just means that the molecule has that charge. For example, a lewis structure for the ion Cl- would be [Cl]-. You know when to put it because it is given to you in the molecular formula.
by tamara masri_3D
Fri Nov 06, 2020 6:56 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge vs. More/Less Valence Electrons
Replies: 3
Views: 29

Re: Formal Charge vs. More/Less Valence Electrons

Hi! That's a great question and i'm not 1000% sure but what I understood from lecture was that the octet concept was a guideline. Basically, you can use it to guide you making lewis structures, but if there is a molecule that for some reason can't form an octet (like BF3) or something in the 3rd ene...
by tamara masri_3D
Fri Nov 06, 2020 6:48 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent bond character
Replies: 3
Views: 34

Re: Covalent bond character

Hello! I think Professor Lavelle was referring to the electron "cloud". He was saying that the electrons in the cloud would be more attracted to the more positive atom in the ionic bond, distorting it from what it would be if the atom was on its own
by tamara masri_3D
Mon Oct 26, 2020 7:45 pm
Forum: Balancing Chemical Reactions
Topic: Text Book Problems
Replies: 3
Views: 36

Re: Text Book Problems

Hello! I think someone asked this in one of Professor Lavelle's office hours and he said we're not expected to know the nomenclature stuff yet. I don't think it will be on the first midterm.
by tamara masri_3D
Mon Oct 26, 2020 7:43 pm
Forum: Photoelectric Effect
Topic: 1B.15
Replies: 3
Views: 51

Re: 1B.15

Hello! In this case, the energy of the photon and the work function should be the same. When the photon reaches a certain energy, it is able to eject the electron with no kinetic energy, which defines the work function as well. Therefore, in this case, the energy needed to remove an electron is comi...
by tamara masri_3D
Mon Oct 26, 2020 7:38 pm
Forum: Photoelectric Effect
Topic: Sapling Week 2 HW_problem #25
Replies: 3
Views: 33

Re: Sapling Week 2 HW_problem #25

Hello! The equation E=hv refers to energy equalling Planck's constant (which is correct) multiplied by the frequency (v) of the light. You inputted the wavelength in the place of frequency and that's why you're getting the wrong answer. Try using c=⋋v to convert wavelength to frequency and you shoul...
by tamara masri_3D
Mon Oct 26, 2020 7:35 pm
Forum: Administrative Questions and Class Announcements
Topic: Modules
Replies: 4
Views: 41

Re: Modules

Hi! I'm not sure, but professor Lavelle mentioned that they took a really long time to make so I would assume that he wouldn't have many new ones in the next few weeks.
by tamara masri_3D
Mon Oct 26, 2020 7:32 pm
Forum: Photoelectric Effect
Topic: Sapling HW #13
Replies: 3
Views: 42

Re: Sapling HW #13

Hello! For this problem, it's telling you that the wavelength of the wave is the same as the length of the bacteria, 2.3 micrometers. From this information, you can find the wavelength in meters and then use the relationship between Planck's constant, and the momentum to find mv (⋋=h/p, p=mv). Then ...
by tamara masri_3D
Thu Oct 22, 2020 9:09 pm
Forum: Quantum Numbers and The H-Atom
Topic: Sapling Question 13
Replies: 4
Views: 51

Re: Sapling Question 13

Hey! So I don't think you need to worry about this for the midterm because Dr. Lavelle said the sapling questions were randomized for some reason so they're kinda out of order (he's trying to get that fixed). But this refers to the electron orbitals that we will go over soon. n is the energy level i...
by tamara masri_3D
Thu Oct 22, 2020 9:04 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Textbook Problem E.23 part d (Calculating amount of moles)
Replies: 2
Views: 34

Re: Textbook Problem E.23 part d (Calculating amount of moles)

Hi again:) So the dot you're referring to in Na2CO3• 10H20 means that you have a hydrated salt. This pretty much says that the water is not chemically bonded to the salt but it's still there and is still necessary in your calculations. For example, when you find the molar mass of the compound (to co...
by tamara masri_3D
Thu Oct 22, 2020 8:58 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Textbook Problem E.25
Replies: 3
Views: 48

Re: Textbook Problem E.25

Hello! Formula units are quite literally the number of "units" you have of a molecule with a specific formula so one molecule of KNO3 would be one formula unit. As for solving the problem, you can do that using the molar masses of the compounds. Hope this helps!
by tamara masri_3D
Thu Oct 22, 2020 8:54 pm
Forum: Properties of Light
Topic: Textbook question 1.A.1
Replies: 2
Views: 26

Re: Textbook question 1.A.1

Hi! That's actually a great question and I'm not 100% sure but I thought that the cathode ray experiment is what showed that electrons are particles because they did not accurately follow the wave model in the experiment.
by tamara masri_3D
Thu Oct 22, 2020 2:20 pm
Forum: *Shrodinger Equation
Topic: Hamiltonian
Replies: 3
Views: 51

Re: Hamiltonian

Hi, I'm not sure if this will be much help, but I understood that the Hamiltonian variable was essentially representing some math function being applied to the wave function. In his lecture, Professor Lavelle said this was originally just the double derivative of the wave function, but now we know t...
by tamara masri_3D
Thu Oct 15, 2020 5:17 pm
Forum: *Black Body Radiation
Topic: Sapling Wk 2+3 #7
Replies: 3
Views: 72

Re: Sapling Wk 2+3 #7

Hello! Since the temp is constant, you don't need to worry about it. Therefore, you can use the equation ⋋=h/mv (where v=velocity)
by tamara masri_3D
Thu Oct 15, 2020 5:13 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: WK 2 Sapling #5
Replies: 4
Views: 71

Re: WK 2 Sapling #5

Hey! When an electron drops from 1 energy level to the next, it gives off energy as light. So you can potentially have a spectral line for every time it drops, which would be 5 times. You can find the wavelengths by plugging the energy levels into the Rydberg equation (v= R{1/n1^2 - 1/n2^2}, where n...
by tamara masri_3D
Thu Oct 15, 2020 5:08 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Delta E
Replies: 5
Views: 54

Re: Delta E

Hey! Yeah, from what I understood you have the right idea:)
by tamara masri_3D
Thu Oct 15, 2020 3:10 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Sapling Wk 2/3 #5
Replies: 2
Views: 50

Re: Sapling Wk 2/3 #5

Hi Kyle, I hope this explanation helps a bit. So when an electron drops from one energy level to the next, it releases that energy. For an electron in n=5 (btw i'm pretty sure the question said n=7 but i'll go with n=5:) the electron can potentially drop 4 energy levels. Dropping to each of these en...
by tamara masri_3D
Wed Oct 14, 2020 8:13 pm
Forum: Properties of Light
Topic: Sapling HW Q 4
Replies: 3
Views: 44

Re: Sapling HW Q 4

Hi Anne, this question was definitely tricky but I hope this helps! So you have a stream of light with a total energy of 2.18x 10^-7 , right? This stream is made up of photons, which each have an energy that eventually adds up to the total. So what you have to do is find the maximum number of photon...
by tamara masri_3D
Tue Oct 06, 2020 8:49 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Fundamentals Review problems question
Replies: 5
Views: 38

Re: Fundamentals Review problems question

Hi Aaina! This is an example of a hydrated salt, which are written as (chemical formula of salt)•_ H2O so in this case, since it's magnesium sulfate heptahydrate, you know you have 7 water molecules attached so it'd be MgSO4•7H2O Also, please keep in mind that when you're calculating the molar mass,...
by tamara masri_3D
Tue Oct 06, 2020 8:26 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamentals G. 5
Replies: 2
Views: 55

Re: Fundamentals G. 5

Hi Jazlyn! So for this question, you definitely have the right idea. You need to find the molarity (mol/L) of the solution so you can then find the volume the student needs to transfer to the buret. When you convert the grams to moles, you have 0.0199mol/250ml, which is the same as saying 0.0199mol/...
by tamara masri_3D
Tue Oct 06, 2020 8:04 pm
Forum: General Science Questions
Topic: Taking Notes on Textbook Readings
Replies: 13
Views: 112

Re: Taking Notes on Textbook Readings

Hi Juwan! From what I understood, it is not required to take notes so it's pretty much up to you and what makes you feel the most comfortable with the material we're supposed to know for exams. It can definitely be beneficial if you didn't completely understand a topic during lecture and you feel li...
by tamara masri_3D
Mon Oct 05, 2020 8:07 pm
Forum: Limiting Reactant Calculations
Topic: Fundamentals M19
Replies: 5
Views: 35

Re: Fundamentals M19

Hello:) So I'm pretty sure that even if you don't know the elements in caffeine, you know that generally, combustion reactions happen in the presence of oxygen. Therefore, you know that all the other elements that are showing up in your products have to come from caffeine, which is the substance bei...
by tamara masri_3D
Mon Oct 05, 2020 8:03 pm
Forum: Limiting Reactant Calculations
Topic: Determining Limiting Reactant
Replies: 7
Views: 57

Re: Determining Limiting Reactant

I'm not sure if I entirely understand the process you're following to find the limiting reactant but I hope this helps: Usually the question will give you the amount of each reactant in terms of grams. Since the stoichiometric coefficients have to do with the number of moles reacting, you need to co...

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