Search found 58 matches

by 005162902
Sun Dec 01, 2019 4:11 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 5
Views: 50

Re: Cisplatin

I would say we need to know that its a coordination compound and the structure (why its cis vs trans). Then I would also know its biological significance as a chemotherapy drug. It is used to stop DNA replication of cancerous cells. The chlorines in cisplatin bind to the guanines in the DNA strand, ...
by 005162902
Sun Dec 01, 2019 4:00 pm
Forum: Hybridization
Topic: Hybridization of Hydrogen
Replies: 3
Views: 20

Re: Hybridization of Hydrogen

Hydrogen only has 1s orbital and can only make one bond, therefore it cannot undergo hybridization.
by 005162902
Sun Dec 01, 2019 3:56 pm
Forum: Lewis Acids & Bases
Topic: Define Acid and Base
Replies: 7
Views: 46

Re: Define Acid and Base

It is different depending on whether you are talking about Lewis or Bronsted Acids and Bases Lewis Acids accept electrons. Lewis Bases donate electrons, inversely: Bronsted Acids donate protons. Bronsted Bases accept protons. Acids and bases are also used when referring to the pH scale. A pH of 7 is...
by 005162902
Sun Dec 01, 2019 3:50 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted Base and Acid
Replies: 5
Views: 31

Re: Bronsted Base and Acid

Yes. A Bronsted Base receives a donated proton. A Bronsted Acid donates the proton to the Bronsted Base. It works oppositely of Lewis Acids and Bases. For Lewis structures, acids accept electrons and bases donate them.
by 005162902
Sun Dec 01, 2019 3:43 pm
Forum: Ionic & Covalent Bonds
Topic: Ionization Energy
Replies: 5
Views: 40

Re: Ionization Energy

Ionization energy increases as you go up the periodic table and to the right of the table. As you travel up the periodic table, the atomic radius of a molecule gets smaller. This places electrons much closer to the nucleus than in a larger molecule making the electrons harder to remove from the smal...
by 005162902
Sun Dec 01, 2019 3:15 pm
Forum: Naming
Topic: Final Exam?
Replies: 20
Views: 128

Re: Final Exam?

It is cumulative and accounts for everything listed in all 6 outlines on the syllabus. I would practice problems from each section and redo problems on the tests we have taken this quarter, especially problems you missed. The final is also on a Sunday don't forget!
by 005162902
Sun Nov 24, 2019 1:05 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination Compound
Replies: 3
Views: 29

Re: Coordination Compound

It is a covalent bond formed between two molecules. However the 2 electrons in the covalent bond come from the same atom. Typically, a covalent bond is formed between two atoms using one electron from each. However a coordinate covalent bond shows that you can create a covalent bond between two atom...
by 005162902
Sun Nov 24, 2019 1:00 pm
Forum: Hybridization
Topic: Strength of sigma and pi bonds
Replies: 8
Views: 32

Re: Strength of sigma and pi bonds

The electrons overlap much closer to the nuclei in sigma bonds. This creates a greater pull on them because of the attraction between the positive nucleus and negative electrons. This strong attraction makes them harder to break than pi bonds, that have less electron overlap.
by 005162902
Sun Nov 24, 2019 12:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle of bent
Replies: 17
Views: 84

Re: Bond Angle of bent

If a lone pair is present, the angle will be less than 109.5 degrees because the electrons will repel the molecules away from it.
by 005162902
Sun Nov 24, 2019 12:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone pairs
Replies: 13
Views: 56

Re: Lone pairs

Lone pairs on the central atom affect molecular shape. Like a bond, they represent a region of electron density on the atom and bend the bonds away from it because of electron repulsion.
by 005162902
Sun Nov 24, 2019 12:52 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Bronsted vs. Lewis Acids
Replies: 9
Views: 42

Re: Bronsted vs. Lewis Acids

The difference between Bronsted and Lewis acids and bases is that Lewis acids accept electrons while bronsted acids accept protons. Lewis bases give electrons while bronsted bases give electrons away. They are the same thing but with protons instead of electrons.
by 005162902
Sun Nov 24, 2019 12:47 pm
Forum: Dipole Moments
Topic: Hydrogen bonding
Replies: 5
Views: 41

Re: Hydrogen bonding

Hydrogen bonding sites are represented by and H paired to an N, O or F so it would look something like this O-H N-H F-H. These bonds would in turn bond to an O, N or F with a lone pair on the opposite antiparallel strand of DNA. The partial positive created on the H in the N,O or F-H bond will be at...
by 005162902
Mon Nov 18, 2019 12:28 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 9
Views: 40

Re: Bond Angles

Drake Choi_1I wrote:I think we will have to memorize the basic ones.

yes know the basic ones but familiarizing yourself with all of them won’t hurt.
by 005162902
Mon Nov 18, 2019 12:26 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Drawing molecules
Replies: 12
Views: 72

Re: Drawing molecules

I think we'll be asked to draw the lowest energy Lewis structure and then name the shape and what the bond angles are. We should know how to draw the most stable Lewis structure and then identify dipoles within the molecule. Using the dipoles we then know the repulsion and shape of the molecule and...
by 005162902
Mon Nov 18, 2019 12:23 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Study Group
Replies: 2
Views: 36

Re: Study Group

Diana A 1G wrote:Hey, I am down for a study group. If anyone wants to form one, email me at dmarut20@gmail.com
And then I'll give you my number:)

I am also struggling and can use some help!! please email me coraf1999@aol.com if you’d like to form a group!
by 005162902
Mon Nov 18, 2019 12:22 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Radicals and molecular shape
Replies: 5
Views: 40

Re: Radicals and molecular shape

TanveerDhaliwal3G wrote:How do radicals affect electron arrangement and shape?

Radicals act as electron density in the shape of the molecule. However since it only has one electron instead of a pair, the repulsion is not as strong as it would be in an area with 2 electrons.
by 005162902
Mon Nov 18, 2019 12:19 am
Forum: Ionic & Covalent Bonds
Topic: types of bonds
Replies: 4
Views: 48

Re: types of bonds

sarahsalama1G wrote:also, are basically LDF in everything?

Yes, basically all molecules demonstrate LDF
by 005162902
Mon Nov 18, 2019 12:17 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 6
Views: 39

Re: Test 2

It covers only the material learned after the midterm. Thankfully it’s not too much content!
by 005162902
Mon Nov 18, 2019 12:16 am
Forum: Bond Lengths & Energies
Topic: Test 2 Topics
Replies: 40
Views: 362

Re: Test 2 Topics

Test 1 will only topics covered after the midterm !
by 005162902
Mon Nov 11, 2019 7:42 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: Test 2
Replies: 6
Views: 59

Re: Test 2

The test is supposed to cover everything from midterm 1 until outline 4. I'm sure he will say in class where the exact cutoff in the outline and notes are. Last time he said specifically in class the stuff that was not going to be on the midterm from that point onward. I am sure he will do the same ...
by 005162902
Mon Nov 11, 2019 7:15 pm
Forum: Trends in The Periodic Table
Topic: Ionization energy
Replies: 6
Views: 53

Re: Ionization energy

oxygen is more likely to lose one electron to get a half-full shell, which is more stable than having 6 valence. Nitrogen is already half full so will likely keep its electrons. This gives O a lower Ionization energy
by 005162902
Mon Nov 11, 2019 7:11 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: The Strength of Hydrogen Bonding
Replies: 4
Views: 22

Re: The Strength of Hydrogen Bonding

although they are strong, hydrogen bonds are not stronger intermolecular forces than covalent or ionic bonds so they are not the strongest overall. It is a permanent dipole of sorts and is stronger than typical dipole-dipole attractions.
by 005162902
Mon Nov 11, 2019 7:09 pm
Forum: Electronegativity
Topic: Formula for Difference
Replies: 7
Views: 52

Re: Formula for Difference

I dont believe we ever calculate electronegativity. We only need to know and understand the electronegativity trends on the periodic table (it increases as you go up and to the right on the table).
by 005162902
Mon Nov 11, 2019 7:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Memorization Tips
Replies: 3
Views: 38

Re: Memorization Tips

I dont have any tips and could use some as well!! Does anyone have a quizlet or a good method they have found??
by 005162902
Mon Nov 11, 2019 7:03 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal charge
Replies: 16
Views: 69

Re: Formal charge

If you can't get all the formal charges to zero, get as many as you can close to zero so that the Formal Charge of the molecule is as low as possible.That will be your most correct answer. It also helps to keep the charge off of the central atom. If the charge is on the outer molecules its easier fo...
by 005162902
Mon Nov 11, 2019 6:58 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: Hydrogen bonding
Replies: 5
Views: 31

Re: Hydrogen bonding

O, N and F have very high electronegativity as well as a small size. These make it easy for hydrogen bonding to occur since they are not strong enough to break the weak H-bond
by 005162902
Mon Nov 11, 2019 6:13 pm
Forum: Student Social/Study Group
Topic: Chem 14B
Replies: 10
Views: 88

Re: Chem 14B

Do you need to take 14C in order to take BL? I am confused about that
by 005162902
Sun Nov 03, 2019 11:57 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic bonds being held together
Replies: 3
Views: 23

Re: Ionic bonds being held together

'in an ionic bond, one molecule is positive and one is negative. Their opposite charges create an electrostatic attraction between the molecules, holding them together.
by 005162902
Sun Nov 03, 2019 11:45 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 18
Views: 109

Re: Resonance Structures

Resonance can be described as the delocalization of electrons in a molecule. The electrons help form bonds within the molecule that can be drawn in Lewis Structures.
by 005162902
Sun Nov 03, 2019 11:37 pm
Forum: Octet Exceptions
Topic: Period 3
Replies: 2
Views: 28

Re: Period 3

I am not 100% sure but I think it has something to do with the fact that these elements are nonmetals with the presence of a d orbital. This somehow allows then to fill and sometimes expand their octets to stabilize the structure.
by 005162902
Sun Nov 03, 2019 11:20 pm
Forum: Formal Charge and Oxidation Numbers
Topic: central atom
Replies: 21
Views: 104

Re: central atom

Yes! If the formal charge of the central atom is zero, the central atom is in a stable state.
by 005162902
Sun Nov 03, 2019 11:19 pm
Forum: Octet Exceptions
Topic: Expanded Octets
Replies: 5
Views: 29

Re: Expanded Octets

in class the examples of elements with expanded orbitals went up to 10.
by 005162902
Sun Nov 03, 2019 11:17 pm
Forum: Trends in The Periodic Table
Topic: Electron Configuration Rules
Replies: 4
Views: 34

Re: Electron Configuration Rules

Pauli's exclusion principle limits orbitals to only 2 electrons each (1 pair of electrons per orbital). Hund's rule states that an orbital must be occupied by one electron before it can be occupied by a second.
by 005162902
Sun Nov 03, 2019 11:15 pm
Forum: General Science Questions
Topic: Study Tactics
Replies: 5
Views: 64

Re: Study Tactics

making sure you know how to use one equation to fill in missing pieces to another is really important as well. Converting units properly and using the necessary formulas for each problem is really important and should be practiced as well!
by 005162902
Mon Oct 28, 2019 12:34 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Finding Most Stable Structure
Replies: 9
Views: 56

Re: Finding Most Stable Structure

Using the equation given in class, you can find the formal charge of a molecule. When the FC equation equals zero, you have reached the most stable form of the compound. If it does not equal zero, you know some modifications can be made to the electrons or bonds in order to reach a FC of zero and ha...
by 005162902
Mon Oct 28, 2019 12:31 pm
Forum: Photoelectric Effect
Topic: kinetic energy
Replies: 6
Views: 50

Re: kinetic energy

This equation along with most we learn in class will be provided (: Lavelle is pretty cool about this, I think he understands there is a lot of equations to keep track of so providing them helps us succeed (:
by 005162902
Mon Oct 28, 2019 12:30 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Multi-electron atoms
Replies: 6
Views: 35

Re: Multi-electron atoms

Nodal planes have no electrons present in them. The s-nodal plane resembles a sphere while the rest all follow lobe-like shapes and patterns.
by 005162902
Mon Oct 28, 2019 12:28 pm
Forum: Ionic & Covalent Bonds
Topic: Ground State
Replies: 11
Views: 65

Re: Ground State

"ground state" represents the lowest energy level possible for a molecule. It is often the state listed on the periodic table, where no electrons have been excited or removed. Just the most basic, low energy state of an element.
by 005162902
Mon Oct 28, 2019 12:25 pm
Forum: Hybridization
Topic: Electrons
Replies: 13
Views: 361

Re: Electrons

"promoted" is just another way of saying an electron has been excited to a new energy level!
by 005162902
Mon Oct 28, 2019 12:19 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Best Way To Study?
Replies: 56
Views: 356

Re: Best Way To Study?

Going to the review sessions is saving me!! In class I find it hard to fully understand topics sometimes because it's so fast and the class is so big. So being in a smaller review or step-up session really helps me because I get more one-on-one help and feel much less intimidated asking questions. E...
by 005162902
Mon Oct 28, 2019 12:19 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Best Way To Study?
Replies: 56
Views: 356

Re: Best Way To Study?

Going to the review sessions is saving me!! In class I find it hard to fully understand topics sometimes because it's so fast and the class is so big. So being in a smaller review or step-up session really helps me because I get more one-on-one help and feel much less intimidated asking questions. E...
by 005162902
Mon Oct 28, 2019 12:15 pm
Forum: Bond Lengths & Energies
Topic: Single bond vs double bond
Replies: 14
Views: 122

Re: Single bond vs double bond

The numbers present in his diagrams were the lengths of the bonds on the molecule. The double bonds had a lower Angstrom value because they are stronger bonds resulting in a stronger pull between molecules. The stronger pull positions them closer together and requires a smaller bond between the mole...
by 005162902
Mon Oct 28, 2019 12:12 pm
Forum: Bond Lengths & Energies
Topic: H bonding
Replies: 14
Views: 505

Re: H bonding

Due to the unique properties of water, it was a higher boiling point. The hydrogen bonds are stronger and require more heat to break them and allow the water to boil to steam.
by 005162902
Mon Oct 28, 2019 12:11 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths
Replies: 15
Views: 139

Re: Bond lengths

Bond lengths equal one Angstrom, and will lively be given. However, double bonds will be shorter than single bonds a lot of the time because they have a stronger pull between molecules, likely pulling them closer together and requiring a shorter bond.
by 005162902
Mon Oct 28, 2019 12:07 pm
Forum: Electronegativity
Topic: Trend of Electronegativity
Replies: 18
Views: 709

Re: Trend of Electronegativity

the trends are identical (: both electronegativity and ionization energy increase as you go up the periodic table and increase also as you go right on the periodic table.
by 005162902
Mon Oct 28, 2019 12:05 pm
Forum: Trends in The Periodic Table
Topic: Electronegativity vs. Electron affinity
Replies: 8
Views: 58

Re: Electronegativity vs. Electron affinity

They are very different. Electron affinity is the energy released when an atom gains an electron. Electronegativity is the atom's tendency to attract a electrons from other elements and is based on the elements location on the periodic table.
by 005162902
Mon Oct 28, 2019 12:01 pm
Forum: Lewis Structures
Topic: lewis structures
Replies: 5
Views: 42

Re: lewis structures

According to my notes the center of the Lewis structure is always the element with the lowest ionization energy. I am not 100% sure on the explanation as to why though.
by 005162902
Mon Oct 28, 2019 11:56 am
Forum: Ionic & Covalent Bonds
Topic: Ionic Bonds confusion
Replies: 7
Views: 51

Re: Ionic Bonds confusion

metals can only give electrons to nonmetals
by 005162902
Mon Oct 28, 2019 11:51 am
Forum: General Rate Laws
Topic: Unique Reaction Rates [ENDORSED]
Replies: 32
Views: 61989

Re: Unique Reaction Rates [ENDORSED]

Peter Dis1G wrote:I think instantaneous rate is the general but more accurate measure of the rate of change of concentration, and unique rate is like the instantaneous rate of individual species. (so the name 'unique')


unique rate is is the same for all reactants because of its coefficients
by 005162902
Mon Oct 28, 2019 11:48 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 2774

Re: Test 1 [ENDORSED]

Ziyan Wang 3J wrote:Does anyone know what will be tested tomorrow? Any topics on quantum world?


all review of highschool chem and topics we covered as review in the syllabus!!
by 005162902
Mon Oct 28, 2019 11:46 am
Forum: Ionic & Covalent Bonds
Topic: Covalent Bonds
Replies: 14
Views: 75

Re: Covalent Bonds

They are only between two nonmetals (:
by 005162902
Mon Oct 28, 2019 11:42 am
Forum: Administrative Questions and Class Announcements
Topic: Class Cancelled Due To Fire?!?
Replies: 4
Views: 71

Re: Class Cancelled Due To Fire?!?

IS CAMPUS GETTING EVACUATED???? I keep hearing mixed answers
by 005162902
Mon Oct 28, 2019 11:29 am
Forum: Administrative Questions and Class Announcements
Topic: Class Cancelled Due To Fire?!?
Replies: 4
Views: 71

Re: Class Cancelled Due To Fire?!?

classes are cancelled (: I am unsure if the sessions are still on though, likely not because of air quality. I heard there's a possibility they may evacuate the school as well but it could just be a rumor.
by 005162902
Mon Oct 28, 2019 11:28 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Multi-electron atoms
Replies: 6
Views: 35

Re: Multi-electron atoms

nodal planes are a zone of the atom with no electrons present.
by 005162902
Mon Oct 28, 2019 11:24 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg equation [ENDORSED]
Replies: 73
Views: 1631

Re: Rydberg equation [ENDORSED]

KHowe_1B wrote:What exactly is the Rydberg equation and how do you know when to use it?


used to measure the wavelength of light emited when an electron moves from one energy level to the next. Energy of the electron changes when it jumps levels so this equation accounts for that.
by 005162902
Mon Oct 28, 2019 11:21 am
Forum: Administrative Questions and Class Announcements
Topic: Accessing the E-textbook [ENDORSED]
Replies: 20
Views: 1093

Re: Accessing the E-textbook [ENDORSED]

Victoria Li 1L wrote:Does anyone know what the Sapling learning thing is? I heard it was extra practice but I was wondering how to access it/what kind of practice it was.


sapling is similar to launchpad for the LS7 series, you practice problems and review concepts. It comes with the textbook lavelle posted on the site!
by 005162902
Mon Oct 28, 2019 11:18 am
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 169
Views: 102933

Re: Rusty on High School Chem [ENDORSED]

GEOVANNAO wrote:any hedrick hall folks want to form a study group?

Hello! I am in chem 14A in hedrick hall on the 3rd floor! Let's set up a study group (: I go to a lot of review sessions if you ever want to go with a buddy
by 005162902
Mon Oct 28, 2019 11:17 am
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 169
Views: 102933

Re: Rusty on High School Chem [ENDORSED]

Hello, what I have found very helpful is going to Lavelle's chem practice and review sessions. There are different types with different styles of learning and I have found them very beneficial for keeping up with new concepts added onto the ones we know from high school. If you are very beginner, I ...

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