Search found 101 matches
- Sat Mar 14, 2020 12:23 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Adding a Catalyst
- Replies: 6
- Views: 1599
Re: Adding a Catalyst
Catalysts do not affect the equilibrium constant. They create a different pathway and, since the equations for K is k over k prime, there shouldn't be a change in K
- Sat Mar 14, 2020 12:17 pm
- Forum: Second Order Reactions
- Topic: Third Order Reactions [ENDORSED]
- Replies: 9
- Views: 771
Re: Third Order Reactions [ENDORSED]
Since Lavelle said he's making the final short and straightforward I don't think he's going to have third order reactions on the exam
- Sat Mar 14, 2020 12:08 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: elementary rate law
- Replies: 4
- Views: 383
Re: elementary rate law
An overall rate law is made up of elementary rate laws (which I believe represents what actually happens in a reaction at a molecular level).
- Sat Mar 14, 2020 11:57 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius Equation
- Replies: 3
- Views: 313
Re: Arrhenius Equation
It can be used to see how activation energy and/or temperature affects the rate constant
- Sat Mar 14, 2020 11:55 am
- Forum: General Science Questions
- Topic: Who makes the Final
- Replies: 23
- Views: 1538
Re: Who makes the Final
I believe Lavelle makes the final
- Sat Mar 14, 2020 11:45 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Week 10 Review Problems
- Replies: 4
- Views: 318
Re: Week 10 Review Problems
Yes, you need a solid metal on that side
- Sat Mar 14, 2020 11:30 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: k
- Replies: 36
- Views: 1717
Re: k
Yes, usually a larger k results in a faster rate of reaction
- Sat Mar 14, 2020 11:28 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration Cells
- Replies: 2
- Views: 303
Re: Concentration Cells
I believe in a concentration cell usually oxidation occurs at the cell with the lower concentration (so this will be the anode) and reduction occurs at the cell with higher concentration (cathode).
- Sat Mar 14, 2020 11:23 am
- Forum: First Order Reactions
- Topic: k versus k prime
- Replies: 6
- Views: 601
Re: k versus k prime
k is the rate constant for the forward reaction, while k prime is the rate constant for the reverse reaction
- Sat Mar 14, 2020 10:14 am
- Forum: Balancing Redox Reactions
- Topic: OH vs H
- Replies: 12
- Views: 914
Re: OH vs H
No, you would use OH- to balance basic solutions instead of H+. However, you do use H2O for balancing in both acidic and basic solutions
- Fri Mar 13, 2020 8:31 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Steady State
- Replies: 2
- Views: 220
Re: Steady State
I think Lavelle said in lecture that we will not be using the steady state method, which is why he didn’t assign any problems where we needed to use that method!
- Fri Mar 13, 2020 8:25 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: 7B.17
- Replies: 1
- Views: 800
Re: 7B.17
It’s given in the problem; the first sentence says “each of the following second-order reactions.”
- Fri Mar 13, 2020 8:20 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalyst in Reaction
- Replies: 1
- Views: 199
Re: Catalyst in Reaction
Catalysts lower the activation energy of a reaction by creating an alternate pathway. Since a higher activation energy leads to a slower rate of reaction, by lowering the activation energy, the catalyst increases the rate of reaction.
- Fri Mar 13, 2020 8:03 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: 7B.1
- Replies: 3
- Views: 318
Re: 7B.1
You plug the initial mass into [A]initial! I suggest rearranging the equation to [A] = [A]initial*e^-kt to make it easier to solve (since you’re solving for [A]) and don’t forget to convert 5.0 hours into minutes (since the units for k is given as min^-1)! Hope this helps :)
- Fri Mar 13, 2020 9:36 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: F in the equation for standard Gibbs energy
- Replies: 4
- Views: 393
Re: F in the equation for standard Gibbs energy
F is Faraday's constant (96,485 C·mol^-1)!
- Thu Mar 12, 2020 7:47 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Topics
- Replies: 10
- Views: 877
Re: Final Topics
The final is cumulative so it's going to cover outlines 1-6!
- Thu Mar 12, 2020 7:41 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: What was your favorite chem topic?
- Replies: 137
- Views: 13448
Re: What was your favorite chem topic?
I think quantum from 14A was my favorite and I love chemical equilibrium from 14B!
- Thu Mar 12, 2020 7:37 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Catalysts and Rates
- Replies: 10
- Views: 691
Re: Catalysts and Rates
Question 7.17E asks whether a catalyst accelerating the third step of a three step reaction would increase the overall rate of reaction. Why is the answer no? I think the answer is no because the rate of the overall reaction depends on the slowest step of the reaction and the third step is the fast...
- Thu Mar 12, 2020 7:32 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry community posts
- Replies: 3
- Views: 331
Re: Chemistry community posts
I think as long as you have 100 or more posts you should be fine (50 from 14A and 50 from 14B)!
- Tue Mar 10, 2020 11:38 pm
- Forum: Administrative Questions and Class Announcements
- Topic: What is the plan for the final?
- Replies: 16
- Views: 1071
Re: What is the plan for the final?
He just sent an email saying it will be a take home final!
- Sun Feb 16, 2020 11:20 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: gibbs free energy -RTlnk
- Replies: 2
- Views: 197
Re: gibbs free energy -RTlnk
I think this equation is used for the system at equilibrium, which is why K (equilibrium constant) is in there!
- Sun Feb 16, 2020 11:15 pm
- Forum: General Science Questions
- Topic: homework for week 7
- Replies: 7
- Views: 496
Re: homework for week 7
I think 5G and 5J from thermodynamics, since 5G talks about the relationship between delta G and K, and 5J talks about the van’t Hoff equation (both of which we covered in lecture on Friday)!
- Sun Feb 16, 2020 11:12 pm
- Forum: Van't Hoff Equation
- Topic: Significance of Van't Hoff Equation
- Replies: 8
- Views: 628
Re: Significance of Van't Hoff Equation
Regarding the reaction, the van’t Hoff equation is basically just telling us that an increase in temperature favors the formation of products if it’s an endothermic reaction, and it favors the formation of reactants if it’s exothermic. Page 433 of the textbook explains this more thoroughly!
- Sun Feb 16, 2020 11:07 pm
- Forum: Phase Changes & Related Calculations
- Topic: Fusion = Melting?
- Replies: 7
- Views: 1039
Re: Fusion = Melting?
Yes fusion is the same as melting; it’s the phase change from a solid to a liquid
- Sun Feb 16, 2020 10:57 pm
- Forum: General Science Questions
- Topic: Studying
- Replies: 67
- Views: 4366
Re: Studying
Doing all the practice problems he gives us is very helpful, as well as making sure you completely understand all the learning objectives! I also recommend watching organic chemistry tutor on YouTube if you don’t understand a concept
- Sun Feb 09, 2020 10:29 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm dates
- Replies: 11
- Views: 534
Re: Midterm dates
The midterm will cover equilibrium, acids/bases, thermochemistry, and thermodynamics (only the first page of the thermodynamics learning outcomes will be covered)
- Sun Feb 09, 2020 10:26 pm
- Forum: Student Social/Study Group
- Topic: Midterm Studying
- Replies: 5
- Views: 396
Re: Midterm Studying
Definitely go over all of Lavelle’s learning outcomes on his website! It might also be helpful to create a list of all the equations that tells you under what conditions to use them/in what type of problems. Also, at the end of each section right before the problems there’s a section that says “the ...
- Sun Feb 09, 2020 10:18 pm
- Forum: Phase Changes & Related Calculations
- Topic: closed vs isolated
- Replies: 10
- Views: 617
Re: closed vs isolated
A closed system can exchange energy with its surroundings but not matter, while an isolated system can’t exchange matter or energy with its surroundings. An example of an isolated system would be a thermos (insulated, neither matter nor energy can be exchanged) and an example of a closed system coul...
- Sun Feb 09, 2020 10:10 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Favorability of Endothermic Reactions
- Replies: 5
- Views: 241
Re: Favorability of Endothermic Reactions
Yes because at higher temperatures there’s more heat and since endothermic reactions absorb heat, the reaction will occur/tend towards the products
- Sun Feb 09, 2020 10:05 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Kelvin or Celsius?
- Replies: 86
- Views: 6407
Re: Kelvin or Celsius?
I think you use Kelvin because the gas constant R always has Kelvin in the denominator so they cancel out!
- Sun Feb 02, 2020 8:21 pm
- Forum: General Science Questions
- Topic: Extra Credit
- Replies: 19
- Views: 873
Re: Extra Credit
Unfortunately I don’t believe Dr Lavelle offers extra credit opportunities
- Sun Feb 02, 2020 8:11 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Phase change
- Replies: 20
- Views: 900
Re: Phase change
Delta H is positive because energy must be used to break the bonds to turn ice into a liquid
- Sun Feb 02, 2020 8:08 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature
- Replies: 14
- Views: 593
Re: Temperature
A negative delta H is exothermic because when energy leaves a constant pressure system as heat, the enthalpy of the system decreases by that amount.
- Sun Feb 02, 2020 7:55 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: deltaU and deltaH
- Replies: 4
- Views: 201
Re: deltaU and deltaH
Delta U is the change in internal energy, while Delta H is the change in enthalpy. The internal energy of a system is the total energy in the system (sum of potential and kinetic energy) while enthalpy is the heat energy that is absorbed or released in a chemical reaction. They’re related in that th...
- Sun Feb 02, 2020 7:45 pm
- Forum: Calculating Work of Expansion
- Topic: Work
- Replies: 4
- Views: 197
Re: Work
Work is a form of energy; when work is done on a system, that means that energy is transferred into the system by its surroundings. The textbook definition of work states that it’s “the process of achieving motion against an opposing force” and is equal to the product of an opposing force and distan...
- Sun Jan 26, 2020 10:02 pm
- Forum: Phase Changes & Related Calculations
- Topic: Focus 4 Homework Questions
- Replies: 3
- Views: 104
Re: Focus 4 Homework Questions
In regards to what we covered in class,4C goes over the heating curve/the basics of enthalpy and 4D goes over hess’s law so for practice problems I’d say both are good but I’d focus more on 4D!
- Sun Jan 26, 2020 9:56 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Week 4 Homework
- Replies: 11
- Views: 371
Re: Week 4 Homework
I think sections 4C and 4D cover all the recent material we’ve done in class so far so I’d do problems from those sections :)
- Sun Jan 26, 2020 9:06 pm
- Forum: Phase Changes & Related Calculations
- Topic: Physical or Phase Changes
- Replies: 7
- Views: 202
Re: Physical or Phase Changes
In all the examples Lavelle has showed in class so far they were given to us so I think the values will be given
- Sun Jan 26, 2020 9:01 pm
- Forum: Phase Changes & Related Calculations
- Topic: Class Lecture to Textbook
- Replies: 2
- Views: 127
Re: Class Lecture to Textbook
Section 4D.4 covers Hess’s Law! 4C and 4D cover pretty much everything we’ve gone over in class so far
- Sun Jan 26, 2020 8:58 pm
- Forum: Phase Changes & Related Calculations
- Topic: enthalpy of phase changes
- Replies: 8
- Views: 270
Re: enthalpy of phase changes
The textbook states that enthalpies of fusion and vaporization are always positive and I’m pretty sure the same goes for the enthalpy of sublimation (since it’s the conversion of a solid to vapor so it’s endothermic)
- Sun Jan 19, 2020 9:37 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5I.13
- Replies: 4
- Views: 169
Re: 5I.13
I’m not sure if this is the right way to do it but what I did was look at the Kc values for both and compared them. Since both are diatomic molecules, they’re more stable in the form F2/Cl2 instead of by themselves, so the one that produces more F2/Cl2 is more stable. Since the equation for Cl2 has ...
- Sun Jan 19, 2020 9:27 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5H.1 and 5H.3?
- Replies: 2
- Views: 93
Re: 5H.1 and 5H.3?
For 5H.1, when you modify a reaction, the K value is also affected. So for part a, since the reaction was flipped backwards, you take the reciprocal of K (1/41) to get 0.024; for Part b, since the reaction was multiplied by 1/2, you take the square root of K to get 6.4; for Part c, since the reactio...
- Sun Jan 19, 2020 9:13 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Henderson Hasselbalch Equation
- Replies: 3
- Views: 258
Re: Henderson Hasselbalch Equation
Dr. Lavelle said that we won’t be using the equation in 14b so I don’t think you need to worry about it!
- Sun Jan 19, 2020 9:10 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Exo/Endo-thermic Rxns
- Replies: 5
- Views: 311
Re: Exo/Endo-thermic Rxns
Endothermic reactions absorb energy to create products while exothermic products release energy when creating products. An example that combines this idea with Le Chatelier’s principle is if you raised the temperature in a reaction; if it’s an endothermic reaction, a higher temperature will cause th...
- Sun Jan 19, 2020 8:54 pm
- Forum: General Science Questions
- Topic: test 1
- Replies: 8
- Views: 330
Re: test 1
Test #1 begins on Tuesday, January 21 in our discussion sections and yes it’s chemical equilibrium and acids and bases (basically everything we’ve learned so far)!
- Sun Jan 12, 2020 7:21 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: increasing N2
- Replies: 5
- Views: 325
Re: increasing N2
If you increase the N2, then the equilibrium will want to shift towards the right to create more ammonia. Creating more ammonia requires using more N2 and H2, thus the amount of H2 will decrease
- Sun Jan 12, 2020 7:18 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: "Quick way" part in Lecture
- Replies: 7
- Views: 230
Re: "Quick way" part in Lecture
If you decrease the volume in the system, then the reaction will favor the direction that has fewer moles of gas (since, according to Le Chatelier’s principle, when stress is applied to a system in equilibrium, the equilibrium will shift to reduce the effect of the stress). By reducing the volume, y...
- Sun Jan 12, 2020 7:01 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: "Quick way" part in Lecture
- Replies: 7
- Views: 230
Re: "Quick way" part in Lecture
Did you mean to write something like “if volume decreases and there’s more moles of gas on the left, then the reaction shifts to the right” and “if volume decreases and there’s more moles of gas on the right, then the reaction shifts to the left”?
- Sun Jan 12, 2020 6:40 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q>K
- Replies: 9
- Views: 331
Re: Q>K
Q is larger than K in situations where there is more products than reactants, in which case the reverse reaction will be favored so that Q = K
- Sun Jan 12, 2020 6:38 pm
- Forum: Ideal Gases
- Topic: partial pressures
- Replies: 7
- Views: 266
Re: partial pressures
The ratio will be the same because (PO2)^3/(PO3)^2 is the formula for its equilibrium constant, K, which always stays the same whether more moles are added or not
- Sun Jan 12, 2020 5:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kc
- Replies: 5
- Views: 239
Re: Kc
I think you can use aqueous solutions and gases to solve for Kc but you don’t include solids or liquids
- Sat Dec 07, 2019 10:09 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Practice Problem
- Replies: 2
- Views: 147
Re: Practice Problem
According to the textbook (Toolbox 9C.1),if it's not a negatively charged complex, you use iron instead of ferrate (ex. [FCl(OH2)5]+ is a pentaaquachlorido(II) ion
- Sat Dec 07, 2019 9:54 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: ph problem
- Replies: 3
- Views: 358
Re: ph problem
Ka is equal to [H+][A-]/[HA] and, for this equation, you can rewrite it as Ka = [H+]^2/[HA] because H+ and A- have the same concentration. To find the pH, you need to take the negative log of the H+ ions. Since they give you Ka and you know the concentration of the acid, you can just plug them in an...
- Sat Dec 07, 2019 9:33 pm
- Forum: Bronsted Acids & Bases
- Topic: Strong Acids and Bases
- Replies: 8
- Views: 585
Re: Strong Acids and Bases
There's a table in the textbook (Fundamentals J) of the strong acids and bases that is pretty helpful! It's Table J.1 on page F75
- Sat Dec 07, 2019 9:25 pm
- Forum: Bronsted Acids & Bases
- Topic: 6C.19
- Replies: 2
- Views: 331
Re: 6C.19
When it comes to oxoacids with the same number off oxygens attached to the central atom, the greater the electronegativity of the central atom, the stronger the acid. This is due to the fact that a greater electronegativity means it's more electron withdrawing. Therefore, HClO4 is stronger than H3PO...
- Sat Dec 07, 2019 9:15 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: QUESTION 4 ON MIDTERM
- Replies: 1
- Views: 256
Re: QUESTION 4 ON MIDTERM
The solutions are on his website! Here's the link: https://lavelle.chem.ucla.edu/wp-conten ... rm_ans.pdf
- Sun Dec 01, 2019 10:40 pm
- Forum: General Science Questions
- Topic: Bruincasts
- Replies: 9
- Views: 791
Re: Bruincasts
I don't think this class has recorded lectures/bruincast. The only recorded lectures he has are the audio-visual focus topics on his website that cover fundamentals and some topics of the quantum world.
- Sun Dec 01, 2019 10:31 pm
- Forum: Student Social/Study Group
- Topic: Studying Videos
- Replies: 3
- Views: 251
Re: Studying Videos
Organic Chemistry Tutor and Professor Dave Explains on Youtube both have great videos for all those topics!
- Sun Dec 01, 2019 10:29 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Textbook
- Replies: 5
- Views: 2143
Re: Textbook
The textbook covers acids and bases in Fundamentals J and Chapter 6. In Lavelle's learning outcomes it says to look at Fundamentals J, Focus 6A.1-6A.3, 6B.1, 6C.3-6C.4, 6D.3, 6E.1 and Box 6E.1
- Sun Dec 01, 2019 10:22 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Basic Acids and Bases Help
- Replies: 3
- Views: 281
Re: Basic Acids and Bases Help
^I agree, Organic Chemistry Tutor is a great resource as well as Professor Dave Explains on Youtube!
- Sun Dec 01, 2019 10:20 pm
- Forum: Bronsted Acids & Bases
- Topic: Naming
- Replies: 4
- Views: 381
Re: Naming
I think we do because it was one of our homework problems (9C.3)
- Sun Nov 24, 2019 6:25 pm
- Forum: Naming
- Topic: Polydentate
- Replies: 1
- Views: 115
Re: Polydentate
A polydentate is basically a ligand that can bind to the central atom at multiple sites (multiple atoms). An example of a monodentate would be H20 (the oxygen makes one bond with the central atom), a bidentate would be oxalate (the two oxygens that are not double bonded to the carbons can each form ...
- Sun Nov 24, 2019 5:59 pm
- Forum: Naming
- Topic: Cobalt vs. Cobaltate
- Replies: 4
- Views: 434
Re: Cobalt vs. Cobaltate
-ate is used if the complex is an anion (is overall negatively charged), so that's when colbatlate would be used. If the complex has an overall positive charge, you would use cobalt.
Re: Prefixes
You use those prefixes when a ligand is a polydentate or if it already has a prefix
- Sun Nov 24, 2019 5:28 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Lecture
- Replies: 3
- Views: 150
Re: Lecture
I believe we still have to cover the acids and bases section before the final
- Sun Nov 24, 2019 5:24 pm
- Forum: Naming
- Topic: using brackets
- Replies: 5
- Views: 452
Re: using brackets
You use brackets for anything within the coordination sphere (basically the complex)
- Sun Nov 17, 2019 10:38 pm
- Forum: Student Social/Study Group
- Topic: Test 2
- Replies: 11
- Views: 574
Re: Test 2
I believe it’s everything we learned after the midterm up to/including sigma and pi bonds
- Sun Nov 17, 2019 10:25 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: bond angles
- Replies: 8
- Views: 470
Re: bond angles
More lone pairs results in more electron-electron repulsion which pushes the atoms away. This results in smaller bond angles because the atoms move closer together.
- Sun Nov 17, 2019 10:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: vsepr angles
- Replies: 10
- Views: 503
Re: vsepr angles
Yes you should memorize them for the upcoming test!
- Sun Nov 17, 2019 10:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs
- Replies: 10
- Views: 570
Re: Lone Pairs
Lone pairs affect molecular geometry because the electron-electron repulsion causes the atoms to move further away
- Sun Nov 17, 2019 10:10 pm
- Forum: Hybridization
- Topic: Test 2
- Replies: 11
- Views: 617
Re: Test 2
I don’t think hybridization is going to be covered on Test 2
- Sun Nov 10, 2019 11:39 pm
- Forum: Resonance Structures
- Topic: Negative Charge
- Replies: 3
- Views: 229
Re: Negative Charge
You put a negative charge on the atom that’s more likely to gain the electron(s) in a bond!
- Sun Nov 10, 2019 11:36 pm
- Forum: Bond Lengths & Energies
- Topic: Test 2 Topics
- Replies: 40
- Views: 2385
Re: Test 2 Topics
I think it’s just everything we learn after the midterm!
- Sun Nov 10, 2019 11:27 pm
- Forum: Student Social/Study Group
- Topic: Midterm Grades
- Replies: 7
- Views: 578
Re: Midterm Grades
I think I remember him saying we get our midterms back on Wednesday!
- Sun Nov 10, 2019 10:06 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma vs Pi
- Replies: 11
- Views: 756
Re: Sigma vs Pi
You can find sigma bonds in single, double, and triple bonds while pi bonds are only found in double bonds (where there’s one sigma and one pi bond) and triple bonds (one sigma and two pi bonds).
- Sun Nov 10, 2019 9:39 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bonds
- Replies: 4
- Views: 234
Re: Hydrogen Bonds
N, O, and F form hydrogen bonds!
- Sun Nov 03, 2019 11:46 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic bonds being held together
- Replies: 3
- Views: 147
Re: Ionic bonds being held together
They’re held together by electrostatic attraction (the attraction between atoms of opposite charges)
- Sun Nov 03, 2019 11:44 pm
- Forum: Photoelectric Effect
- Topic: Best way to study for this topic?
- Replies: 8
- Views: 445
Re: Best way to study for this topic?
Definitely do the homework problems and also search up more problems online if you need more practice! To understand the topic better conceptually I recommend reading the textbook and watching videos about the topic online (the organic chemistry tutor on YouTube has really good ones)
- Sun Nov 03, 2019 11:30 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration
- Replies: 3
- Views: 1202
Re: Electron Configuration
You want to remove electrons from higher energy levels before moving onto lower energy levels, so you’ll want to remove them from the highest orbital. They’re also usually easier to remove because they’re further away from the nucleus
- Sun Nov 03, 2019 11:26 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: magnetic quantum number
- Replies: 5
- Views: 216
Re: magnetic quantum number
The magnetic quantum number describes the number of orbitals within a subshell and the orientation of the orbital; s will have a magnetic quantum number of 0, p can have one between -1 and 1, d can have between -2 and 2, and so on
- Sun Nov 03, 2019 11:18 pm
- Forum: Trends in The Periodic Table
- Topic: Midterm Question Regarding Metals, Nonmetals, etc
- Replies: 2
- Views: 99
Re: Midterm Question Regarding Metals, Nonmetals, etc
I don’t think we’ll specifically asked to identify if the element is a metal, nonmetal, etc. but I think it’s still good information to know because you need it for many things (like naming, bonding, etc)
- Sun Oct 27, 2019 10:58 pm
- Forum: Resonance Structures
- Topic: Midterm
- Replies: 4
- Views: 155
Re: Midterm
Anish Patel 4B wrote:Do you know if this also includes the material from the first test since it was high school stuff?
I think material from the first test is also included in the midterm!
- Sun Oct 27, 2019 10:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Midterm Format
- Replies: 11
- Views: 542
Re: Midterm Format
I know it's still weeks away but I was wondering, does anyone know about the format of the midterm? Is it comparable to Test 1 but just longer in length? What types of questions will be on it and which units does it cover? Where is the midterm located? Will that be announced closer to the midterm d...
- Sun Oct 27, 2019 10:50 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Bonds
- Replies: 14
- Views: 1140
Re: Covalent Bonds
Yes, covalent bonds are only between two nonmetals! If you have a metal-nonmetal bond it's an ionic bond and a metal-metal is a metallic bond.
- Sun Oct 27, 2019 10:42 pm
- Forum: Ionic & Covalent Bonds
- Topic: Resonance Structures
- Replies: 5
- Views: 148
Re: Resonance Structures
I think you have to use the dots to represent the two electrons on the oxygen
- Sun Oct 27, 2019 10:41 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Advice for studying
- Replies: 92
- Views: 9243
Re: Advice for studying
For studying I definitely recommend reading the textbook chapters (which helps a lot with conceptual understanding of topics), doing all the homework problems, and just searching up youtube videos of topics you don't fully understand!
- Sun Oct 20, 2019 11:01 pm
- Forum: Properties of Light
- Topic: Homework 4
- Replies: 4
- Views: 231
Re: Homework 4
I think we can still do questions under quantum world since it falls under the category of “recently covered material”
- Sun Oct 20, 2019 10:53 pm
- Forum: Student Social/Study Group
- Topic: Week 4 HW Problems
- Replies: 7
- Views: 333
Re: Week 4 HW Problems
I think it can be from both. In the syllabus it says to hand in homework from recently covered material so I believe either should be fine (it also could depend on your discussion section; for example if you had yours on Tuesday, we haven’t really gone over Chemical bonds yet so I don’t think they’d...
- Sun Oct 20, 2019 10:43 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1F.19
- Replies: 3
- Views: 151
Re: 1F.19
Since s-block metals have lower ionization energies, they’re more likely to give away their electrons which makes them more reactive
- Sun Oct 20, 2019 10:32 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Quantum Numbers: Size of An Atom
- Replies: 4
- Views: 150
Re: Quantum Numbers: Size of An Atom
n is related to the size and energy of the orbital; as n (aka the energy level) increases, the mean distance of an electron from the nucleus increases, which means the radius of the atom gets larger.
- Sun Oct 20, 2019 10:24 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Writing Electron Configurations
- Replies: 2
- Views: 112
Re: Writing Electron Configurations
In general, you would follow the order of s, p, d, f but I think there are some special cases in which you don’t follow that order (for example, copper)
- Sun Oct 13, 2019 10:21 pm
- Forum: General Science Questions
- Topic: Powerpoint Slides
- Replies: 4
- Views: 270
Re: Powerpoint Slides
I don’t think he posts his slides, but the audio-visual focus topics do go over what he talks about in class (though they only seem to be available for fundamentals and quantum world).
- Sun Oct 13, 2019 10:11 pm
- Forum: Properties of Electrons
- Topic: Photon
- Replies: 5
- Views: 171
Re: Photon
Photons are basically particles of energy that make up light
- Sun Oct 13, 2019 10:02 pm
- Forum: Properties of Light
- Topic: 1B #19
- Replies: 1
- Views: 76
Re: 1B #19
To calculate the different wavelengths, use de Broglie’s equation (λ = h/mv) and you just search up the mass of the proton and neutron because they’re set values and plug those in for m, plug in 2.75 x 10^5m/s for v, and plug in Planck’s constant for h: Proton: (6.626 x 10^-34Js)/(1.673 x 10^-27kg)(...
- Sun Oct 13, 2019 9:23 pm
- Forum: Photoelectric Effect
- Topic: Wavelength, Frequency, and Intensity
- Replies: 7
- Views: 1184
Re: Wavelength, Frequency, and Intensity
Light is made up of photons and the photon’s energy is dependent on its wavelength; longer wavelengths of light have less energy than shorter wavelengths, which is why the shorter wavelengths are able to eject the electrons (since they have more energy and you need to reach a certain threshold to ej...
- Sun Oct 13, 2019 9:02 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect
- Replies: 3
- Views: 225
Re: Photoelectric Effect
No, the surface must be metal to exhibit the photoelectric effect because you have to be able to completely remove the electron in order to achieve the effect. Since metals are able to donate/spare electrons while non-metals can’t, only metals will work.
- Sun Oct 06, 2019 9:39 pm
- Forum: Significant Figures
- Topic: Sig Figs
- Replies: 3
- Views: 114
Re: Sig Figs
Sig figs are basically like a way to round. Khan Academy is a great resource to learn more about the basics of sig figs :)
- Sun Oct 06, 2019 9:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Specific type of calculator for tests?
- Replies: 6
- Views: 361
Re: Specific type of calculator for tests?
I think we have to use scientific calculators for tests!
- Sun Oct 06, 2019 9:15 pm
- Forum: Significant Figures
- Topic: Reviewing Sig Figs
- Replies: 3
- Views: 167
Re: Reviewing Sig Figs
For sig fig practice I like using Khan Academy or if you just search up “sig fig practice,” some good websites for practice will pop up (like sciencegeek.net)!
- Sun Oct 06, 2019 9:10 pm
- Forum: Balancing Chemical Reactions
- Topic: Fractions
- Replies: 34
- Views: 1499
Fractions
I know this was kind of addressed in a question someone asked earlier but I just wanted to ask if we would be marked down if we left the stoichiometric coefficient as a fraction? I know different professors prefer different things so I just wanted to clarify to see if it would necessarily be seen as...