Search found 108 matches

by Omar Selim 1D
Fri Mar 13, 2020 6:12 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow Step Mechanism
Replies: 7
Views: 69

Re: Slow Step Mechanism

It is reaction dependent and there is no general assumption that can be made unless give the problem's specifics
by Omar Selim 1D
Fri Mar 13, 2020 6:08 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 11
Views: 142

Re: Final

Lavelle's emails provide all the information we need to know about the final.
by Omar Selim 1D
Fri Mar 13, 2020 6:06 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: calorimetry
Replies: 6
Views: 106

Re: calorimetry

Regular calorimeters assume constant pressure while bomb calorimeters assume constant volume. They are both isolated systems
by Omar Selim 1D
Fri Mar 13, 2020 5:40 pm
Forum: Administrative Questions and Class Announcements
Topic: "Open Book" Final?
Replies: 30
Views: 752

Re: "Open Book" Final?

He said he'd update us tomorrow so I feel like we shouldn't worry or stress about it right now and instead just focus on studying and it'll work out.
by Omar Selim 1D
Fri Mar 13, 2020 5:37 pm
Forum: Student Social/Study Group
Topic: Tips for Staying Focused
Replies: 8
Views: 204

Re: Tips for Staying Focused

People can stay focused in different ways. I like to drink coffee or tea while i study because it keeps me awake and alert
by Omar Selim 1D
Thu Mar 12, 2020 7:48 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: final
Replies: 3
Views: 91

Re: final

I think we can assume that the final will include about equal amounts of most outlines
by Omar Selim 1D
Wed Mar 11, 2020 1:08 am
Forum: Student Social/Study Group
Topic: Final Exam
Replies: 22
Views: 564

Re: Final Exam

The final will be take-home and straight forward according to the email sent a few hours ago.
by Omar Selim 1D
Sun Mar 08, 2020 11:39 pm
Forum: Student Social/Study Group
Topic: Midterm and Final Question
Replies: 18
Views: 257

Re: Midterm and Final Question

The study guide would be all of Lavelle’s outlines from the beginning of the quarter
by Omar Selim 1D
Sun Mar 08, 2020 11:38 pm
Forum: Administrative Questions and Class Announcements
Topic: 100 or 50 posts?
Replies: 8
Views: 97

Re: 100 or 50 posts?

You should have 100 posts
by Omar Selim 1D
Sun Mar 08, 2020 11:37 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Notation Layout
Replies: 7
Views: 53

Re: Cell Notation Layout

Convention states that the anode (oxidation) should be on the left
by Omar Selim 1D
Sun Mar 08, 2020 11:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Grades
Replies: 22
Views: 279

Re: Test 2 Grades

We will probably get them back in time before the final to look over it
by Omar Selim 1D
Sun Mar 08, 2020 11:35 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Midterm
Replies: 2
Views: 82

Re: Midterm

I remember the question. For that, you needed to consider enthalpy change by relating equations
by Omar Selim 1D
Fri Feb 28, 2020 10:34 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 10
Views: 88

Re: Test 2

Lavelle mentioned in class that test 2 will cover outline 4 (that wasn't on the midterm) and outline 5. It is important to understand that none of the concepts can be taken in isolation and an understanding of previous concepts and outlines is necessary to do your best on test 2.
by Omar Selim 1D
Fri Feb 28, 2020 10:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode vs Cathode
Replies: 15
Views: 122

Re: Anode vs Cathode

Fundamentally, oxidation happens at the anode and reduction happens at the cathode. In terms of writing it out, you typically include the anode on the left and the cathode on the right.
by Omar Selim 1D
Fri Feb 28, 2020 8:52 pm
Forum: Balancing Redox Reactions
Topic: How to tell if its being reduced or oxidized
Replies: 15
Views: 196

Re: How to tell if its being reduced or oxidized

You have to differentiate between the ions you are looking at. One of the elements gains electrons while the other loses. the mnemonic to help you remember the definitions of oxidation and reduction if that was your confusion is OIL RIG: Oxidation Is Losing; Reduction Is Gaining.
by Omar Selim 1D
Fri Feb 28, 2020 8:45 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Porous Disk and Salt Bridge
Replies: 13
Views: 460

Re: Porous Disk and Salt Bridge

I don't believe there is a difference in efficiency. They serve the same purpose in balancing charges and the distribution of ions.
by Omar Selim 1D
Fri Feb 28, 2020 9:21 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 4
Views: 69

Salt Bridge

Hi everyone,
My question refers to salt bridges and what they provide to each part of the diagram. I was confused on how they play a role in balancing charges? Do they provide electrons to one side or ions? Also, why don't they dissociate completely dissociate in the solutions they're in?
by Omar Selim 1D
Sun Feb 23, 2020 4:21 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: relevance of salt bridge
Replies: 9
Views: 56

Re: relevance of salt bridge

A salt bridge essentially allows the "circuit" to be complete. It allows for a constant flow of charge without an immediate stop as a result of charge build-up. It essentially balances charge in ot=rder to keep the system going.
by Omar Selim 1D
Sun Feb 23, 2020 4:19 pm
Forum: Student Social/Study Group
Topic: Curve?
Replies: 31
Views: 1345

Re: Curve?

There is no curve in the class, but points and grade correlation are not determined until after the final exam has been posted. Your scores on the tests are not indicative of what your final grade will come out to be as Dr. Lavelle might adjust it slightly at the end of the quarter depending on what...
by Omar Selim 1D
Sun Feb 23, 2020 4:13 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Material
Replies: 16
Views: 252

Re: Test 2 Material

The material covered in test 2 will not include information from the coming weeks. He postponed it in order to give us more time to study for it.
by Omar Selim 1D
Sun Feb 23, 2020 4:11 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Spontaneous
Replies: 23
Views: 338

Re: Spontaneous

In order for a reaction to be considered spontaneous, the value of delta G must be a negative number. delta g = delta H - TDELTAS. If delta g is 0, the reaction is at equilibrium.
by Omar Selim 1D
Sun Feb 23, 2020 4:09 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 9
Views: 82

Re: Salt Bridge

I believe the best way to understand the concept of a salt bridge is to liken it to a closed circuit. In order for a circuit to be complete, there must be a closed-loop in order for charges of positives and negatives to get balanced and have somewhere to go. The salt bridge essentially completes the...
by Omar Selim 1D
Sun Feb 16, 2020 9:02 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: When to use the different equations
Replies: 5
Views: 75

When to use the different equations

Hi all,

So I'm having trouble figuring out when to use delta G = -RTlnk vs. the other equations for delta G. Is there a reason you would pick one equation over another? and what do you do differently when it is determined at constant pressure vs. volume
by Omar Selim 1D
Sun Feb 16, 2020 8:56 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Midterm Curve
Replies: 45
Views: 503

Re: Midterm Curve

On his syllabus it says that he does not curve but that grades will be determined at the end of the quarter
by Omar Selim 1D
Wed Feb 12, 2020 8:13 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Adiabatic
Replies: 2
Views: 40

Re: Adiabatic

An adiabatic system means that the system is isolated and therefore delta U = w + 0(q)
by Omar Selim 1D
Wed Feb 12, 2020 8:11 am
Forum: Calculating Work of Expansion
Topic: Midterm equation sheet
Replies: 16
Views: 196

Re: Midterm equation sheet

Yes, however, it is helpful to know the equations before hand because the units, definitions, and terms are not provided
by Omar Selim 1D
Wed Feb 12, 2020 8:08 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Boltzmann Formula
Replies: 3
Views: 53

Re: Boltzmann Formula

Yes, it is one of the topics Lavelle discussed in lecture and it is included in outline 4
by Omar Selim 1D
Tue Feb 04, 2020 12:55 am
Forum: Administrative Questions and Class Announcements
Topic: Video Outlines
Replies: 3
Views: 130

Video Outlines

Are there video outlines for any of the recent topics?
by Omar Selim 1D
Tue Feb 04, 2020 12:54 am
Forum: Administrative Questions and Class Announcements
Topic: Course Reader
Replies: 1
Views: 44

Course Reader

How do we access the course reader?
by Omar Selim 1D
Tue Feb 04, 2020 12:54 am
Forum: Administrative Questions and Class Announcements
Topic: Midterm
Replies: 6
Views: 66

Midterm

Which equations should we memorize/ will need to know off the top of our heads for the midterm?
by Omar Selim 1D
Tue Feb 04, 2020 12:51 am
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: defintion
Replies: 6
Views: 71

Re: defintion

Internal energy is just the energy found within a system without any interference from the world beyond. It is the concept of energy only being from the kinetic and potential energy already found within a system
by Omar Selim 1D
Tue Feb 04, 2020 12:49 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy
Replies: 2
Views: 23

Enthalpy

Is enthalpy just the change in energy? what does it mean to have a positive or negative change in enthalpy? When would such changes occur?
by Omar Selim 1D
Tue Feb 04, 2020 12:47 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Differences between systems
Replies: 3
Views: 37

Differences between systems

I am still a little bit confused on the difference between a closed and isolated system. Could someone provide the definitions and explain the differences?
by Omar Selim 1D
Sun Feb 02, 2020 1:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 5 Homework
Replies: 7
Views: 83

Re: Week 5 Homework

Since the midterm is soon, you can pick any of the topics we've already gone over. It might be most helpful to review topics from the most recent lectures
by Omar Selim 1D
Sun Feb 02, 2020 1:47 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Elements
Replies: 8
Views: 41

Re: Elements

Diatomic molecules such as H2, O2, N2, F2, I2, CL2, and Br2 all have an enthalpy of formation of 0 because it is their naturally occuring state. There is no enthalpy of formation for the way something is already formed. However, if you were to change the molecule, then there would be an enthalpy of ...
by Omar Selim 1D
Sun Feb 02, 2020 1:43 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy units
Replies: 4
Views: 31

Re: Entropy units

As long as all the calculations are correct and the units match up then you can use either one. However, changing units constantly may result in accidental mix ups, so you should be fine as long as you stay consistent
by Omar Selim 1D
Sun Feb 02, 2020 1:42 pm
Forum: Phase Changes & Related Calculations
Topic: Calorimeter
Replies: 8
Views: 100

Re: Calorimeter

A bomb calorimeter is a more robust and accurate calorimeter. It can withstand more pressure, so it is typically more often used
by Omar Selim 1D
Sun Feb 02, 2020 1:40 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated System
Replies: 4
Views: 33

Re: Isolated System

In an isolated system, energy is transferred, so q=0, q=0, and delta u also equals 0
by Omar Selim 1D
Sun Jan 26, 2020 7:55 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: solvent
Replies: 10
Views: 56

Re: solvent

A solvent is the substance in excess that other reactants are being dissolved in. E.g. Water is a solvent. Salt is a solute
by Omar Selim 1D
Sun Jan 26, 2020 7:53 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: exo thermic
Replies: 11
Views: 154

Re: exo thermic

In an exothermic reaction, heat is found on the right side of the equation, therefore, by adding heat, you would shift the reaction away from where there is an excess so it would shift to the left (reactants).
by Omar Selim 1D
Sun Jan 26, 2020 7:51 pm
Forum: Administrative Questions and Class Announcements
Topic: Fall Quarter Final?
Replies: 12
Views: 278

Re: Fall Quarter Final?

I would email the TA from last quarter's discussion section asking when a good time would be to come and pick up the tests
by Omar Selim 1D
Sun Jan 26, 2020 7:50 pm
Forum: Phase Changes & Related Calculations
Topic: Heat vs temperature
Replies: 6
Views: 82

Re: Heat vs temperature

Temperature and heat are different in that for a sample of boiling water, the temperature would remain the same until it undergoes a phase change while heat would be continuously added
by Omar Selim 1D
Sun Jan 26, 2020 7:48 pm
Forum: Phase Changes & Related Calculations
Topic: Why does steam cause burns?
Replies: 29
Views: 253

Re: Why does steam cause burns?

Steam causes burns due to the high amount of heat transferred from the steam to skin. It has a large Q and H value.
by Omar Selim 1D
Sun Jan 26, 2020 7:47 pm
Forum: Phase Changes & Related Calculations
Topic: Delta H
Replies: 3
Views: 22

Re: Delta H

All the necessary information regarding what is needed for a problem would be provided. It is best to know how to calculate Delta H in case it is one of the values unaccounted for, but otherwise, it would be provided. We are not expected to memorize any values.
by Omar Selim 1D
Fri Jan 17, 2020 9:27 am
Forum: Administrative Questions and Class Announcements
Topic: Grading
Replies: 8
Views: 149

Re: Grading

Ask your TA because it varies depending on the TA's preference. Just to be sure, I recommend posting at least 5 times a week.
by Omar Selim 1D
Fri Jan 17, 2020 9:18 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Stress
Replies: 4
Views: 41

Re: Stress

A stress applied to the system is any altercation made that shifts the reaction rates. Stressors include temperature, pressure, the removal or addition of a product or reaction, and the addition of a different reactive sbstance
by Omar Selim 1D
Fri Jan 17, 2020 9:15 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic
Replies: 5
Views: 58

Re: Exothermic

Energy is released when bonds are formed because the atoms go to a lower energy state that is more stable.
by Omar Selim 1D
Fri Jan 17, 2020 9:14 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Tips for Test
Replies: 23
Views: 262

Re: Tips for Test

I would read the textbook first as it is the most in depth review of the lecture material you could get. I would then review the lecture notes then do the homework, going over how to approach the homework problems if you get them wrong.
by Omar Selim 1D
Fri Jan 17, 2020 9:12 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Kw
Replies: 16
Views: 128

Re: Kw

Kw = 1.0 *10^-14 is the equilibrium constant for water, which is also defined as Kw = Ka * Kb. The two definitions you gave are interchangeable for the most part
by Omar Selim 1D
Sun Jan 12, 2020 3:54 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 1 date
Replies: 4
Views: 49

Re: Test 1 date

Dr. Lavelle has the test and exam schedule on the class webpage. For test 1, it will be starting on Tuesday the 21st in your discussion section
by Omar Selim 1D
Sun Jan 12, 2020 3:52 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Test 1
Replies: 6
Views: 70

Re: Test 1

Test 1 is starting on Jan 21st in your discussion section. Dr. Lavelle has the tests/exam schedule up on the class page
by Omar Selim 1D
Sun Jan 12, 2020 3:50 pm
Forum: Administrative Questions and Class Announcements
Topic: General HW question
Replies: 9
Views: 92

Re: General HW question

The TAs said that it is graded based on a demonstrated effort of answering 5 questions. This is due to the fact that we have access to the solution manual so grading on how many are correct wouldn't be as effective and would dissuade students from actually trying
by Omar Selim 1D
Sun Jan 12, 2020 3:48 pm
Forum: Ideal Gases
Topic: Topics on Test 1
Replies: 37
Views: 416

Re: Topics on Test 1

Outline 1 and everything mentioned in the assigned readings/homework assignments/lectures. I believe that test 1 will hold us accountable for everything up until the lecture right before the test
by Omar Selim 1D
Sun Jan 12, 2020 3:46 pm
Forum: Ideal Gases
Topic: Test 1
Replies: 7
Views: 89

Re: Test 1

The best way to determine that is through lectures and the readings on the syllabus. I believe that in the syllabus Dr. Lavelle mentioned that 1 question on every test will be from the homework problems, so those are also a great way of studying.
by Omar Selim 1D
Sun Jan 12, 2020 3:44 pm
Forum: Administrative Questions and Class Announcements
Topic: 14A Final Pickup
Replies: 5
Views: 80

Re: 14A Final Pickup

You'll be able to start picking them up next week from Young Hall. Room 3034 I believe. I'm not sure when the last day to pick them up is but Dr. Lavelle sent out the info in an email a few weeks after the final.
by Omar Selim 1D
Sun Jan 12, 2020 3:42 pm
Forum: Ideal Gases
Topic: Units of Pressure
Replies: 8
Views: 73

Re: Units of Pressure

It is helpful to understand the general proportionalities between the different units of pressure because although we will be getting a conversion sheet, sometimes you may have used a wrong conversion that you could easily identify based on what you would approximate it to be.
by Omar Selim 1D
Wed Dec 04, 2019 6:05 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: 1
Views: 53

Hydrogen bonding

What is a hydrogen bond site? and for hydrogen bonding to occur do both compounds need to contain a hydrogen bonded to F O or N or can you have one compound that involves a bond between H and F O or N and the other compound to just be an F O or N not bonded to a H. For example is the bond between H3...
by Omar Selim 1D
Wed Dec 04, 2019 6:00 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: hybridizing coordination compounds
Replies: 1
Views: 29

hybridizing coordination compounds

Do you hybridize coordination compounds and the ligands they contain? and if so how?
by Omar Selim 1D
Wed Dec 04, 2019 11:15 am
Forum: Naming
Topic: Determining Type of Ligand
Replies: 2
Views: 34

Re: Determining Type of Ligand

There are also certain ones you should commit to memory. Those being:
EDTA (can be hexadente)
Ethylenediamine (can be bidente)
diethylenetriamine(can be tridente)
oxalato (can be bidente)
by Omar Selim 1D
Wed Dec 04, 2019 10:28 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Drawing structures on the final
Replies: 3
Views: 49

Drawing structures on the final

Are we expected to know how to draw different coordination compound structures? do we need to know how to draw chelating coordination compounds?
by Omar Selim 1D
Wed Dec 04, 2019 10:26 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Isomers on the final
Replies: 1
Views: 24

Isomers on the final

to what extent do we have to understand the topic of isomers and the idea of cis vs trans? do we have to be able to identify different types of isomers on the final?
by Omar Selim 1D
Wed Dec 04, 2019 9:12 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Do we need to know the formation constant?
Replies: 1
Views: 39

Re: Do we need to know the formation constant?

It would be helpful to understand the general concept. The equilibrium constant is set up mainly to show what the reaction favors and what the complex's ligands are most likely to be. When analyzing reactions involving the equilibrium constant, it is generally a formation of the products over the re...
by Omar Selim 1D
Sat Nov 30, 2019 10:24 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Grades
Replies: 10
Views: 164

Re: Test 2 Grades

Most likely, I would assume, they would be up by Wednesday's lecture in order to give us adequate time to go over them before the final
by Omar Selim 1D
Sat Nov 30, 2019 10:23 pm
Forum: Hybridization
Topic: What to consider for hybridization?
Replies: 3
Views: 45

Re: What to consider for hybridization?

consider lewis structure, orbitals, and electron pairs which also get hybridized
by Omar Selim 1D
Sat Nov 30, 2019 10:21 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Calculating pOH
Replies: 2
Views: 38

Re: Calculating pOH

It is material that most likely will be covered in the next lecture but if you are preparing early, it is always better to over prepare than under prepare
by Omar Selim 1D
Sat Nov 30, 2019 10:19 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: What to know for the final
Replies: 8
Views: 117

Re: What to know for the final

I would assume it would not be on the final and that only lecture content and readings will be covered
by Omar Selim 1D
Sat Nov 30, 2019 10:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Exam Content
Replies: 14
Views: 184

Re: Final Exam Content

The final will be cumulative of everything since the beginning of the quarter
by Omar Selim 1D
Sat Nov 30, 2019 10:14 pm
Forum: Student Social/Study Group
Topic: Final Preparation
Replies: 2
Views: 51

Re: Final Preparation

I feel like it would be best to prepare with the mindset that all topics would be covered equally
by Omar Selim 1D
Sun Nov 24, 2019 1:03 pm
Forum: Hybridization
Topic: Strength of sigma and pi bonds
Replies: 8
Views: 92

Re: Strength of sigma and pi bonds

sigma bonds are harder to break than pi bonds because the former are a result of end-to-end bonding while the latter consist of side-to-side bonds
by Omar Selim 1D
Wed Nov 20, 2019 4:04 pm
Forum: Electronegativity
Topic: electronegativity of hydrogen
Replies: 3
Views: 107

Re: electronegativity of hydrogen

Ionic character depends on the difference in electronegativity values. The greater the difference, the more ionic
by Omar Selim 1D
Wed Nov 20, 2019 4:02 pm
Forum: General Science Questions
Topic: Test 2
Replies: 7
Views: 151

Re: Test 2

It all has to be memorized, but i found that ionce you understand 1 row, the rest become easier
by Omar Selim 1D
Wed Nov 20, 2019 2:06 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Boiling/melting points
Replies: 5
Views: 52

Re: Boiling/melting points

The boiling point and melting point depend on the strength of the bonds. Typically stronger bonds mean a higher boiling/melting point
by Omar Selim 1D
Fri Nov 15, 2019 11:07 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Formula Notation
Replies: 4
Views: 50

Re: VSEPR Formula Notation

The letters represent: the central atom, bonds, and lone pairs
- A = Central atom
- X = Bonds
- E = Lone pairs
by Omar Selim 1D
Fri Nov 15, 2019 11:05 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Polar vs Nonpolar molecules
Replies: 4
Views: 70

Re: Polar vs Nonpolar molecules

The best way to determine whether or not a molecule is non-polar or polar is by analyzing the vectors of electron distribution and pulls depending on electronegativity
by Omar Selim 1D
Fri Nov 15, 2019 11:03 am
Forum: Bond Lengths & Energies
Topic: Bond lengths
Replies: 8
Views: 83

Re: Bond lengths

Because each element has different bond lengths depending on what it is being bonded with, we would probably be given the bond lengths in a question
by Omar Selim 1D
Fri Nov 15, 2019 11:00 am
Forum: Sigma & Pi Bonds
Topic: Hybridization
Replies: 2
Views: 51

Hybridization

We talk about hybridization a lot, but what does it actually mean for certain bonds to be hybridized? and do we hybridize all molecules?
by Omar Selim 1D
Fri Nov 15, 2019 10:58 am
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Viscosity/Surface Tension
Replies: 4
Views: 134

Re: Viscosity/Surface Tension

The result of higher strength intermolecular forces, resulting from the hydrogen bonds between the water molecules, it is harder to break apart those bonds, which causes surface tensions
by Omar Selim 1D
Sun Nov 10, 2019 8:48 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: Polarizability
Replies: 3
Views: 26

Re: Polarizability

For anions, polarizability increases the more electrons it has. For cations, it depends on how small and how charged the ions are
by Omar Selim 1D
Sun Nov 10, 2019 8:46 pm
Forum: Lewis Structures
Topic: Electronegative
Replies: 14
Views: 133

Re: Electronegative

Yes, electronegativity describes the pull of electrons. It increases up and to the right of the periodic table
by Omar Selim 1D
Wed Nov 06, 2019 12:39 pm
Forum: Properties of Light
Topic: De Broglie for Photon?
Replies: 3
Views: 160

Re: De Broglie for Photon?

You don't know the mass of a photon so debroigle's equation would not be applicable
by Omar Selim 1D
Wed Nov 06, 2019 12:37 pm
Forum: Quantum Numbers and The H-Atom
Topic: orbitals vs. subshells
Replies: 4
Views: 150

Re: orbitals vs. subshells

When thinking about what defines an orbital or subshell with respect to quantum numbers, Ml would refer to orbitals while L refers to the s, p, d. f,.. subshells.
by Omar Selim 1D
Wed Oct 30, 2019 12:09 am
Forum: Ionic & Covalent Bonds
Topic: grading
Replies: 5
Views: 82

Re: grading

It is either on My UCLA under "discussions" or the actual lecture
by Omar Selim 1D
Wed Oct 30, 2019 12:07 am
Forum: Octet Exceptions
Topic: aufbau principle
Replies: 8
Views: 140

Re: aufbau principle

There's less energy in the 3rd energy level than the 4th, because of the reality that it takes more energy to maintain stability in the 4th energy level
by Omar Selim 1D
Wed Oct 30, 2019 12:06 am
Forum: Bond Lengths & Energies
Topic: Bond lengths
Replies: 15
Views: 214

Re: Bond lengths

There's no formula but there are very specific lengths for certain bonds that I doubt will be expected knowledge to know on the test
by Omar Selim 1D
Wed Oct 30, 2019 12:04 am
Forum: Ionic & Covalent Bonds
Topic: Valence e-
Replies: 3
Views: 62

Re: Valence e-

It's good practice to understand the whole concept of valence shells, but also understand that the bohr model is not always representative of reality
by Omar Selim 1D
Tue Oct 29, 2019 11:57 pm
Forum: Ionic & Covalent Bonds
Topic: Octet Rule
Replies: 8
Views: 107

Re: Octet Rule

Elements in row 3 and beyond is usually the rule of thumb because they have empty orbitals
by Omar Selim 1D
Wed Oct 23, 2019 12:46 pm
Forum: General Science Questions
Topic: Study Tips
Replies: 13
Views: 233

Re: Study Tips

The homework problems are helpful once you already understand the information so I recommend going to review sessions/ watching helpful chemistry videos then doing the homework problems slowly and making sure you understand why you got a certain answer
by Omar Selim 1D
Wed Oct 23, 2019 12:42 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity Trends
Replies: 5
Views: 64

Re: Electron Affinity Trends

When thinking about electron affinity think about how close the electrons are to the nucleus (where the protons are). Electron affinity increases the closer the electrons are to the nucleus, so it increases as it goes up and to the right
by Omar Selim 1D
Wed Oct 23, 2019 12:38 pm
Forum: Resonance Structures
Topic: polarity
Replies: 1
Views: 67

polarity

Do different resonance structures affect the polarity of molecules?
by Omar Selim 1D
Wed Oct 23, 2019 12:33 pm
Forum: Ionic & Covalent Bonds
Topic: Difference Between Ionic and Covalent
Replies: 8
Views: 434

Re: Difference Between Ionic and Covalent

Ionic bonds occur after electrons have been completely transferred over while covalent bonds are the sharing of ekectrons.
by Omar Selim 1D
Wed Oct 23, 2019 12:30 pm
Forum: Lewis Structures
Topic: Lewis Structure angles
Replies: 3
Views: 51

Re: Lewis Structure angles

Probably try to be as accurate as possible but you don't have to be exact. As long as you have the right attempt, you don't need to use a protractor or anything that specific
by Omar Selim 1D
Wed Oct 16, 2019 12:28 pm
Forum: Properties of Light
Topic: Concept of Rainbows
Replies: 1
Views: 53

Re: Concept of Rainbows

Possibly because the light is not diffracted enough due to the size of the water droplet, or the rainbow could be very small and hard to notice
by Omar Selim 1D
Wed Oct 16, 2019 12:26 pm
Forum: Molarity, Solutions, Dilutions
Topic: What is Molarity?
Replies: 11
Views: 393

Re: What is Molarity?

Molarity is moles/liters. It refers to the concentration of atoms/molecules in a solvent. When something refers to transferring a specific molarity of a substance, it is talking about a certain concentration of that liquid
by Omar Selim 1D
Wed Oct 16, 2019 12:22 pm
Forum: SI Units, Unit Conversions
Topic: Chemistry Grades
Replies: 4
Views: 74

Re: Chemistry Grades

Our TA said grades would be input as soon as assignments go in and they can be checked on MyUCLA
by Omar Selim 1D
Wed Oct 16, 2019 12:19 pm
Forum: DeBroglie Equation
Topic: ionization energy
Replies: 2
Views: 71

Re: ionization energy

Ionization energy is the amount of energy it requires to remove an electron from an atom's valence shell, which is similar to the definition of work function
by Omar Selim 1D
Wed Oct 16, 2019 12:17 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Question regarding definition of molecules
Replies: 5
Views: 246

Re: Question regarding definition of molecules

The constant refers to the amount (6.022*10^23) in a mole of a unit. It could be either a molecule, or an atom as long as it is 1 unit.
by Omar Selim 1D
Sun Oct 13, 2019 8:51 pm
Forum: SI Units, Unit Conversions
Topic: knowing how many sig figs to use
Replies: 17
Views: 283

Re: knowing how many sig figs to use

Sig Figs are important and you should keep them in mind while you're doing a problem but only round at the end
by Omar Selim 1D
Sun Oct 13, 2019 8:49 pm
Forum: Properties of Light
Topic: Wavelength
Replies: 3
Views: 25

Wavelength

Why does a shorter wavelength mean there is more energy?
by Omar Selim 1D
Sun Oct 13, 2019 8:36 pm
Forum: Trends in The Periodic Table
Topic: electronegativity
Replies: 10
Views: 2528

Re: electronegativity

Electronegativity is the strength atoms have in puling other electrons to complete their valence shell

Go to advanced search