Search found 112 matches

by Matthew ILG 1L
Sat Mar 14, 2020 12:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 275
Views: 131418

Re: Saying Thank You to Dr. Lavelle

I'm really going to miss Dr. Lavelle. I'm really bummed that we won't be able to say goodbye and thank you to him in class. I just want to say thank you to Dr. Lavelle for the last two quarters of chemistry and my first experiences in a college classroom. I had a truly great experience with him as a...
by Matthew ILG 1L
Sat Mar 14, 2020 12:40 pm
Forum: Zero Order Reactions
Topic: Composition vs Decomposition
Replies: 3
Views: 66

Composition vs Decomposition

Is there a diffference in which equation is used when a problem asks to find the "rate of decomposition" of a molecule vs when it asks you to find the rate of composition of a molecule?
by Matthew ILG 1L
Sat Mar 14, 2020 12:38 pm
Forum: Zero Order Reactions
Topic: Equations for 0, 1st, and 2nd order reactions
Replies: 4
Views: 59

Equations for 0, 1st, and 2nd order reactions

Looking back through my notes, I realize I have several different equations for each order rxn and I am not sure which one to use or which is most common when asked to simply find the rate of decomposition of something. Would someone be willing to clarify the basic equation for each order rxn please...
by Matthew ILG 1L
Wed Mar 11, 2020 12:34 am
Forum: Administrative Questions and Class Announcements
Topic: What is the plan for the final?
Replies: 16
Views: 214

Re: What is the plan for the final?

Is there a due date for the final? The email did not say anything about when the final will be due.
by Matthew ILG 1L
Wed Mar 11, 2020 12:32 am
Forum: General Science Questions
Topic: Dr. Lavelle [ENDORSED]
Replies: 2
Views: 135

Dr. Lavelle [ENDORSED]

I'm really going to miss Dr. Lavelle. I'm really bummed that we won't be able to say goodbye and thank you to him in class. I just want to say thank you to Dr. Lavelle for the last two quarters of chemistry and my first experiences in a college classroom. I had a truly great experience with him as a...
by Matthew ILG 1L
Tue Mar 10, 2020 5:04 pm
Forum: Administrative Questions and Class Announcements
Topic: Discussion Sections
Replies: 4
Views: 56

Re: Discussion Sections

We have yet to receive any official word from the chem department but hopefully we will receive an email soon about discussion sessions, as well as the review sessions and final.
by Matthew ILG 1L
Tue Mar 10, 2020 4:57 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry 14B Final
Replies: 9
Views: 225

Re: Chemistry 14B Final

Yeah we have not received any official word on the situation from the chem department or Dr. Lavelle, so I am not sure what the situation is for the final or the review sessions. At least we finished learning all the material already.
by Matthew ILG 1L
Tue Mar 10, 2020 4:55 pm
Forum: Student Social/Study Group
Topic: Number of Chemistry Community Posts
Replies: 33
Views: 614

Re: Number of Chemistry Community Posts

I was curious about this too and whether or not we simply needed 100 posts by the end of this quarter. I believe I had more than 50 last quarter but was not sure if I would still need 50 more posts this quarter or just the remainder to 100.
by Matthew ILG 1L
Tue Mar 10, 2020 4:52 pm
Forum: Administrative Questions and Class Announcements
Topic: ***New Coronavirus Update from UCLA***
Replies: 2
Views: 99

Re: ***New Coronavirus Update from UCLA***

I believe we are still waiting on specific news and updates for chemistry and from Dr. Lavelle.
by Matthew ILG 1L
Tue Mar 10, 2020 4:49 pm
Forum: Administrative Questions and Class Announcements
Topic: Final exam content
Replies: 15
Views: 300

Re: Final exam content

The final will be cumulative, and I believe that only one or two problems will be from the homework, as with most of his other midterms and finals.
by Matthew ILG 1L
Tue Mar 10, 2020 4:48 pm
Forum: Student Social/Study Group
Topic: Final
Replies: 21
Views: 291

Re: Final

There have not been any announcements made yet by Dr. Lavelle but the letter from Chancellor Block said that there would be more updates from professors in the coming days.
by Matthew ILG 1L
Mon Mar 09, 2020 1:07 pm
Forum: Biological Examples
Topic: Catalysts
Replies: 6
Views: 62

Catalysts

In today's lecture(3/9/20) Dr. Lavelle gave an example of how Nitric Oxide catalyses the conversion of oxygen to ozone in lower atmosphere.
He stated that NO(g) is a catalyst. However, is O2(g) also a catalyst?
It is not formed at any point during the process, so I assume it is not an intermediate.
by Matthew ILG 1L
Tue Mar 03, 2020 10:15 pm
Forum: Administrative Questions and Class Announcements
Topic: HW Sections
Replies: 2
Views: 37

Re: HW Sections

5G and 5J are the only sections from thermo that were not included on the midterm
by Matthew ILG 1L
Tue Mar 03, 2020 10:14 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 5G.15
Replies: 3
Views: 45

Re: 5G.15

I'm almost certain that this is an error in the textbook; I've done that same problem twice and I've gotten your answer twice. You may want to see Prof. Lavelle's updated solutions manual errors on his website to see if this is one of the errors. But I can assure you that your work is correct. Than...
by Matthew ILG 1L
Tue Mar 03, 2020 10:12 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: G=-nFE equation [ENDORSED]
Replies: 4
Views: 159

Re: G=-nFE equation [ENDORSED]

Will we lose points on the test or final if we forget to include the degree sign?
by Matthew ILG 1L
Tue Mar 03, 2020 10:09 pm
Forum: General Science Questions
Topic: Test 2
Replies: 12
Views: 232

Re: Test 2

Test 1 only had 7 or 8 I thought. Does that mean that test two is going to be longer?
by Matthew ILG 1L
Tue Mar 03, 2020 10:08 pm
Forum: Van't Hoff Equation
Topic: derivation?
Replies: 3
Views: 82

Re: derivation?

I believe that we only need to know the final equation at the end of the derivation. We only derive the formula in class to understand where the equation comes from. But I do not think we will be asked to derive any equations or formulas on any test or exam.
by Matthew ILG 1L
Tue Mar 03, 2020 10:06 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student - Part II [ENDORSED]
Replies: 150
Views: 10619

Re: Advice from a Medical Student - Part II [ENDORSED]

I was just wondering how applicable the things you learned in 14A and 14B were to you when you were doing your medical internship.
by Matthew ILG 1L
Sat Feb 29, 2020 11:08 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.13
Replies: 5
Views: 117

Re: 5J.13

You know that K decreases as temperature increases. This means that the reaction is exothermic. Because of this, the reactants are favored, and increasing the temperature will result in a shift to the reactant side. More ammonia will NOT be formed, because this is a product. You do not need an ICE ...
by Matthew ILG 1L
Fri Feb 28, 2020 8:57 pm
Forum: Van't Hoff Equation
Topic: 5G.21
Replies: 4
Views: 117

Re: 5G.21

I have tried part A several times but I keep coming up with K=1.096. How does the book manage to get 1.0 x 10^80. Does it have something to do with the 2 in front of H20 in the balanced equation?
The only Standard Gibbs free energy of formation given by the appendix is -228.57 for H2O I believe.
by Matthew ILG 1L
Fri Feb 28, 2020 8:37 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: No partial pressure given for 5.G.19
Replies: 1
Views: 17

Re: No partial pressure given for 5.G.19

Wait sorry I just realized that you use the deltaG°=-RTlnK.
by Matthew ILG 1L
Fri Feb 28, 2020 8:25 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: No partial pressure given for 5.G.19
Replies: 1
Views: 17

No partial pressure given for 5.G.19

On textbook problem 5.G.19, it asks to calculate the standard Gibbs free energy for the reaction i2(g) <--> 2i(g), where K=6.8 at 1200.K The problem does not give us any partial pressures, so I was wondering what formula or equation should be used, or if there is a way to find the partial pressure u...
by Matthew ILG 1L
Fri Feb 28, 2020 8:15 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 10
Views: 76

Re: Test 2

The hw problems you should do to review are 5G and 5J, as well as 6K through 6O
by Matthew ILG 1L
Wed Feb 26, 2020 3:59 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: log or ln
Replies: 6
Views: 52

Re: log or ln

You are able to use either the log or ln, and I believe Dr. Lavelle provided an equation using each. However, he also stated that log is often preferred by scientists because pH also uses log.
by Matthew ILG 1L
Wed Feb 26, 2020 3:56 pm
Forum: General Science Questions
Topic: HW Problems for Test 2
Replies: 5
Views: 153

HW Problems for Test 2

I know that test 2 will cover the second page of thermodynamics, but I was wondering which hw problems related to that second page?
Are 4i and 4J included in that, or is it only 5G and 5J problems?
by Matthew ILG 1L
Sun Feb 23, 2020 4:56 pm
Forum: Balancing Redox Reactions
Topic: spontaneous
Replies: 15
Views: 129

Re: spontaneous

A reduction is spontaneous when the standard reduction potential is positive.
by Matthew ILG 1L
Sun Feb 23, 2020 4:34 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: salt bridge
Replies: 10
Views: 61

Re: salt bridge

A salt bridge is a laboratory device used to connect the oxidation and reduction half-cells of a galvanic cell(a type of electrochemical cell). It maintains electrical neutrality within the internal circuit, preventing the cell from rapidly running its reaction to equilibrium.
by Matthew ILG 1L
Sun Feb 23, 2020 4:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 275
Views: 131418

Re: Saying Thank You to Dr. Lavelle

Thank you Dr. Lavelle for always doing your best to make chemistry fun, from the comics on slides to the music before or after lecture, to the little notes spaced throughout the midterm and final that always bring a smile to my face. Thank you.
by Matthew ILG 1L
Sun Feb 23, 2020 4:18 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Material
Replies: 16
Views: 204

Re: Test 2 Material

No additional material! Just the second page of outline 4 (thermodynamics, focus 5) and outline 5 (electrochemistry).
by Matthew ILG 1L
Mon Feb 10, 2020 4:37 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4C.3
Replies: 7
Views: 97

Re: 4C.3

Is the change in enthalpy supposed to be much larger for part b than it is for part a?
by Matthew ILG 1L
Mon Feb 10, 2020 3:21 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Example 4.c.1
Replies: 2
Views: 24

Example 4.c.1

I am on problem 4.c.3 in the book, and the example 4.c.1 is very similar to it. However, in the example, it says that Cv=5/2R, and that Cp=7/2R because in the book Cp=Cv+R.
On our equation sheet, it says that Cp=5/2R. I am confused as to which ratio is correct for Cp and Cv when converting to R.
by Matthew ILG 1L
Sun Feb 09, 2020 11:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Homework 4A13
Replies: 5
Views: 105

Re: Homework 4A13

On this same problem, why don't we use the molarity or volume of either of the compounds that are given to us in the problem? Why do we just multiply C(cal) by delta T. Hello, I believe we do this because the relationship q= -qcal is already established. It is simpler to find qcal with the informat...
by Matthew ILG 1L
Sun Feb 09, 2020 11:09 pm
Forum: Phase Changes & Related Calculations
Topic: 4B.5
Replies: 7
Views: 99

Re: 4B.5

Will the conversion of 1atm=760 Torr be given to us at all? I have yet to find that on the equations sheet from test one. I could be looking in all the wrong places though.
by Matthew ILG 1L
Sun Feb 09, 2020 10:47 pm
Forum: Administrative Questions and Class Announcements
Topic: midterm format
Replies: 8
Views: 78

Re: midterm format

There are occasionally a few true or false or fill in the blank questions thrown in to the test, but the rest is all free response.
by Matthew ILG 1L
Sun Feb 09, 2020 10:42 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Internal Energy
Replies: 4
Views: 163

Re: Internal Energy

I was just on this problem and luckily found this post. Are we supposed to know that 1atm is equivalent to 760 torr or is that somewhere on the equation sheet? Also how do we convert from L*atm to kJ?
by Matthew ILG 1L
Sun Feb 09, 2020 10:23 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: m and n in heat capacity
Replies: 4
Views: 34

Re: m and n in heat capacity

I believe that the mass and moles can both be used because the two can be converted back an forth, given the correct and necessary information. They both work, similar to how ceclius and kelvin both work at times. It can be changed to moles or to grams, but we do not need to because the equation wor...
by Matthew ILG 1L
Sun Feb 09, 2020 10:17 pm
Forum: General Science Questions
Topic: Midterm Review Questions ?
Replies: 3
Views: 66

Re: Midterm Review Questions ?

Thank you both very much. That is very helpful.
by Matthew ILG 1L
Sun Feb 09, 2020 9:55 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Homework 4A13
Replies: 5
Views: 105

Re: Homework 4A13

On this same problem, why don't we use the molarity or volume of either of the compounds that are given to us in the problem? Why do we just multiply C(cal) by delta T.
by Matthew ILG 1L
Sun Feb 09, 2020 8:46 pm
Forum: Phase Changes & Related Calculations
Topic: reversible
Replies: 4
Views: 51

Re: reversible

A reversible reaction is basically when the reactants form products that, in turn, react together to give the reactants back. It is shown by the two way arrows usually.
by Matthew ILG 1L
Sun Feb 09, 2020 8:44 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Intensive vs. Extensive
Replies: 15
Views: 213

Re: Intensive vs. Extensive

Extensive properties, such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present
by Matthew ILG 1L
Sun Feb 09, 2020 8:35 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Entropy in reversible reactions
Replies: 2
Views: 30

Re: Entropy in reversible reactions

ΔS total =ΔS system +ΔS surrounding So if the ΔS total =0, then ΔS system = -ΔS surrounding They will not always be equal and opposite, but that is typically when this relationship will be important. Also, you could solve for ΔS system and ΔS surrounding and add if the question is asking for the ΔS...
by Matthew ILG 1L
Sun Feb 09, 2020 8:33 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Volume decrease
Replies: 7
Views: 96

Re: Volume decrease

The rule of less moles only applies when you are dealing with gases. If the substances in the rxn are not gases, then I do not believe the rule applies.
by Matthew ILG 1L
Sun Feb 09, 2020 8:32 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: reversible vs. irreversible
Replies: 3
Views: 46

Re: reversible vs. irreversible

In a irreversible reaction, the reactants react to form the products, which cannot revert back into reactants. In reversible reactions, as the reactants react with other reactants to form products, the products are reacting with other products to form reactants. Combustion is an example of an irreve...
by Matthew ILG 1L
Sun Feb 09, 2020 8:30 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Weak acid/base
Replies: 14
Views: 139

Re: Weak acid/base

Mariana Fuentes 1L wrote:Does that mean that Ka and pKa are kind of opposite?

Yes exactly!! The smaller the value of Ka, the larger the value of pKa, the weaker the acid.
by Matthew ILG 1L
Sun Feb 09, 2020 8:29 pm
Forum: General Science Questions
Topic: Midterm Review Questions ?
Replies: 3
Views: 66

Midterm Review Questions ?

I'm going through and doing problems from each section of the book to prepare for the midterm. Does anyone have any especially good problems they would suggest doing in preparation for the midterm? Can be from any section we have covered. Thank you
by Matthew ILG 1L
Sun Feb 09, 2020 8:27 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE BOX
Replies: 27
Views: 216

Re: ICE BOX

I believe that Dr. Lavelle said we can ignore x when K<10^-3.
by Matthew ILG 1L
Thu Feb 06, 2020 7:21 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: 3rd Law
Replies: 4
Views: 25

Re: 3rd Law

The third law acts similar to a limit function in calculus:
As the temperature of the system approaches absolute zero, the entropy of the system approaches zero.
by Matthew ILG 1L
Wed Feb 05, 2020 8:28 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated
Replies: 14
Views: 103

Re: closed vs isolated

Isolated systems are completely sealed and closed off. Imagine a test tube with a lid on it, then wrapped completely in a "puff jacket" as Dr. Lavelle said in his in class example from a few weeks ago. It does not interact with its environment at all.
by Matthew ILG 1L
Wed Feb 05, 2020 8:22 pm
Forum: General Science Questions
Topic: Class before Midterm
Replies: 2
Views: 48

Class before Midterm

Does anybody know if we will be learning new material for the entirety of Friday's class, or will part of it be review and example problems for the midterm?
by Matthew ILG 1L
Sun Feb 02, 2020 9:01 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Shifts
Replies: 6
Views: 109

Re: Shifts

If you are referring to K value vs Q value:
When Q>K, the rxn will shift to the left, creating more reactants
When Q<K, the rxn will shift to the right, creating more products
by Matthew ILG 1L
Sun Feb 02, 2020 8:53 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: U and H
Replies: 2
Views: 55

Re: U and H

U = q - w is used when there is heat added to the system (q). H = U + PV is under constant pressure and constant temperature.
by Matthew ILG 1L
Sun Feb 02, 2020 8:01 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: Types of entropy
Replies: 2
Views: 21

Re: Types of entropy

I may be wrong, but I believe the Boltzmann equation is still used for positional entropy.
by Matthew ILG 1L
Thu Jan 30, 2020 1:01 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Celcius and Kelvin
Replies: 11
Views: 75

Re: Celcius and Kelvin

We needed to know the conversion from celcius to kelvin on the last test, so I assume that on the midterm and other tests we will need to have it memorized as well. However, I do not believe we need to use the exact conversion value of 273.15, but rather we are bale to use 273.
by Matthew ILG 1L
Thu Jan 30, 2020 12:59 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: memorize
Replies: 6
Views: 49

Re: memorize

Water is one heat capacity you should memorize. Other than that, the heat capacity of different elements is usually given in the specific problem.
by Matthew ILG 1L
Wed Jan 29, 2020 1:19 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed vs isolated systems
Replies: 24
Views: 145

Re: Closed vs isolated systems

Dr. Lavelle gave a good example today in lecture. He said a closed system in a closed system, energy can still exchange with surrounding, but matter is not exchanged (i.e a sealed beaker of water. the beaker does not insulate) In a isolated system, nothing exchanged with the surroundings. It is as i...
by Matthew ILG 1L
Wed Jan 29, 2020 12:55 pm
Forum: Lewis Acids & Bases
Topic: Lewis acid and bases
Replies: 5
Views: 99

Re: Lewis acid and bases

Lewis acids and bases are defined in terms of being able to accept or donate electron pairs, while Bronsted Lowry acids and bases are defined in terms of being able to accept or donate hydrogen ions ( H+ )
by Matthew ILG 1L
Wed Jan 29, 2020 12:54 pm
Forum: Administrative Questions and Class Announcements
Topic: 14A Final Pickup
Replies: 3
Views: 58

Re: 14A Final Pickup

Thank you! I still have yet to pick mine up as well.
by Matthew ILG 1L
Wed Jan 29, 2020 12:47 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Work
Replies: 6
Views: 65

Re: Work

"In chemistry, the convention is that anything going out of the system is negative and anything coming into the system is positive. If your system is a gas in a piston, work is being done on the system when it is being compressed, so the work done on the system is positive, and the work done by...
by Matthew ILG 1L
Sat Dec 07, 2019 1:32 pm
Forum: Bronsted Acids & Bases
Topic: Naming Acids and Bases
Replies: 1
Views: 32

Naming Acids and Bases

On question 6.A.7, it asks us to write the name of each acid based on the molecular drawing (HClO3 and HNO3).
Is there a list of acid names we are expected to memorize and know, or is there a way to know the names of these acids based on the formula and atoms within it.
by Matthew ILG 1L
Sat Dec 07, 2019 1:28 pm
Forum: Hybridization
Topic: 2sp2 vs sp2
Replies: 3
Views: 49

Re: 2sp2 vs sp2

You usually add the 2 i front of the sp2 when you are describing the hybridization of a bond. If you are just describing the hybridization of an individual molecule, I don't believe that you need the 2 in front.
by Matthew ILG 1L
Fri Dec 06, 2019 4:30 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Deciding shape
Replies: 3
Views: 75

Re: Deciding shape

If you determine the coordination number you can determine how many molecules bond to it, if you find this out you can find the molecular shape. I agree with this. the coordination number helps you determine the shape. Some common ones are: CN=6 is Octahedral CN=4 is tetrahedral or in the case of c...
by Matthew ILG 1L
Fri Dec 06, 2019 4:25 pm
Forum: Naming
Topic: Naming
Replies: 2
Views: 44

Re: Naming

The Ta's and Ua's have said that either is acceptable as well. Which ever naming convention is easiest for you to remember.
by Matthew ILG 1L
Fri Dec 06, 2019 4:23 pm
Forum: Conjugate Acids & Bases
Topic: Conjugate acids and bases
Replies: 2
Views: 39

Re: Conjugate acids and bases

In addition to this, a weak acid leads to a strong conjugate base. And vise versa, a strong acid leads to a weak conjugate base.
by Matthew ILG 1L
Mon Dec 02, 2019 11:30 pm
Forum: Naming
Topic: Cyano vs. Cyanido
Replies: 2
Views: 40

Re: Cyano vs. Cyanido

I found a chem community post from 2011 that said this:
"They are actually the same ligand, but the the first (cyano) is an older naming convention. Cyanido is the IUPAC preferred name for the ligand".
It also says that both forms are acceptable.
by Matthew ILG 1L
Mon Dec 02, 2019 11:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 9 and 10 Homework
Replies: 2
Views: 59

Re: Week 9 and 10 Homework

Coordination compounds and acid and base structures are the newest material, but I'm pretty sure that if you do older problems as a way to review for the final your TA will accept that as well. But it may be better to be safe and just turn in problems from the coordination compounds and acid and bas...
by Matthew ILG 1L
Mon Dec 02, 2019 11:26 pm
Forum: General Science Questions
Topic: Final test locations
Replies: 4
Views: 94

Re: Final test locations

I'm sure he will also show the locations on a slide in class on Wednesday or Friday, like he did for the midterm. He showed a quick glimpse of it in class today as well, and I believe A-L last names are in CS50, though I'm not sure where M-Z last names are.
by Matthew ILG 1L
Mon Dec 02, 2019 11:18 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Strength of Strong Acids
Replies: 2
Views: 35

Re: Strength of Strong Acids

I believe that the stronger the acid, the weaker the bond, and therefore the easier it is for that bond to break and for the acid to completely dissociate in water. So to answer your question, what sets certain acids apart as "stronger" and varying levels of dissociating completely is the ...
by Matthew ILG 1L
Mon Dec 02, 2019 10:49 pm
Forum: Naming
Topic: Latin names of Elements
Replies: 1
Views: 27

Latin names of Elements

Will we be required to know and memorize the latin names of elements for the final? A video I watched kept using the latin names, such as cobalt being cobaltate and platinum being platinate when naming their coordinate compounds. Will a list of latin anmes of elements be given on the final or do we ...
by Matthew ILG 1L
Sun Dec 01, 2019 6:51 pm
Forum: Administrative Questions and Class Announcements
Topic: Points
Replies: 11
Views: 152

Re: Points

I have heard that the discussion posts have been graded both ways in the past. Some years they grade on a week to week basis and other years they simply check your total number of posts at the very end. It is good to try and stay up to date, but if you fall behind, talking with your TA is never a ba...
by Matthew ILG 1L
Sun Dec 01, 2019 6:42 pm
Forum: General Science Questions
Topic: Memorization for Final
Replies: 2
Views: 44

Re: Memorization for Final

You will also need to know unit conversions I believe, such as grams to kilograms or meters to nanometers.
by Matthew ILG 1L
Sun Dec 01, 2019 6:36 pm
Forum: General Science Questions
Topic: Week 10 Classes
Replies: 7
Views: 147

Week 10 Classes

Will we be learning new material throughout the entirety of this week (December 2-6) for the final? Or will the last Friday of class be a review day for our final?
by Matthew ILG 1L
Sun Dec 01, 2019 6:33 pm
Forum: Student Social/Study Group
Topic: Final Studying
Replies: 8
Views: 98

Re: Final Studying

In addition to the review sessions, are there any specific videos or chemistry youtubers you would suggest watching who are good at teaching the more conceptual things?
by Matthew ILG 1L
Sun Dec 01, 2019 6:30 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Relative acidity
Replies: 7
Views: 132

Re: Relative acidity

The strength of an acid depends on two things: The strength of the A-H bond, and the stability of the resulting anion. Bond strength is related to the length of the bond, and because Iodine has a much larger atomic radius than Fluorine, HI has a much longer, and therefore weaker, bond. The hydrogen ...
by Matthew ILG 1L
Sun Dec 01, 2019 6:27 pm
Forum: Student Social/Study Group
Topic: Study Strategies
Replies: 6
Views: 86

Re: Study Strategies

It sounds like you are doing fine in the class. I would say that reading over some of the textbook and attending the workshops are very helpful in reviewing and applying what we learned in lecture. When reading over the textbook do you suggest taking notes? I have tried to read it and it just gets ...
by Matthew ILG 1L
Sun Dec 01, 2019 6:25 pm
Forum: Lewis Acids & Bases
Topic: Difference between Lewis and Bronsted Acids?
Replies: 2
Views: 37

Re: Difference between Lewis and Bronsted Acids?

The Bronsted definition: an acid is a proton (H+ ion) donor, and a base is a proton acceptor
The Lewis definition: an acid is an electron acceptor, and a base is an electron donor.
by Matthew ILG 1L
Wed Nov 27, 2019 4:43 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 7a
Replies: 6
Views: 77

Re: Test 2 7a

Yes, you coun't the number of lone pairs and hydrogens and you should get 11 bonding sites. You may get 12 but my TA said that the Hydrogen that is on the most far right that is bonded to carbon cannot form a hydrogen bond because hydrogens need to bond to N O or F (or small molecules..) and since ...
by Matthew ILG 1L
Wed Nov 27, 2019 4:42 pm
Forum: Sigma & Pi Bonds
Topic: Question on Test 2
Replies: 11
Views: 260

Re: Question on Test 2

For this question, you had to be able to identify that all the single bonds had a sigma bond in it and that all the double bonds that a sigma bond and a pi bond in it. When counting the number of hydrogen bonding sites you need to include the H-bonds already present and the lone pairs on N,O, or F....
by Matthew ILG 1L
Wed Nov 27, 2019 4:35 pm
Forum: Hybridization
Topic: sigma or pi?
Replies: 20
Views: 214

Re: sigma or pi?

The way i remember is: Sigma=Single. The double S helps me out. Also sigma bonds are every bond in a structure.
by Matthew ILG 1L
Wed Nov 27, 2019 4:33 pm
Forum: Bronsted Acids & Bases
Topic: Acids vs Bases
Replies: 5
Views: 64

Re: Acids vs Bases

In addition to the difference between acids and bases, there is also a difference between organic acids and bases vs inorganic acids and bases. Acids containing carbon are known as organic acids. Bases containing carbon are known as organic bases. Acids that do NOT contain carbon are known as inorga...
by Matthew ILG 1L
Wed Nov 27, 2019 4:30 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Inorganic vs organic
Replies: 5
Views: 61

Re: Inorganic vs organic

Acids containing carbon are known as organic acids. Bases containing carbon are known as organic bases. Acids that do NOT contain carbon are known as inorganic acids or mineral acids. Bases that do NOT contain carbon are known as inorganic bases.
by Matthew ILG 1L
Thu Nov 14, 2019 1:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 15
Views: 215

Re: Test 2

What topics should we expect to show up on test #2? From what I've heard, Test 2 will cover material up until Friday's lecture. Based on this, questions on Test 2 can appear from any material up until VSEPR. This includes, but is not limited to: 1. Review of high school chemistry 2. Quantum 3. Chem...
by Matthew ILG 1L
Thu Nov 14, 2019 1:13 pm
Forum: Student Social/Study Group
Topic: Final Exam
Replies: 10
Views: 160

Re: Final Exam

So the final is cumulative, but Test #2 is just information from after the midterm?
by Matthew ILG 1L
Thu Nov 14, 2019 1:12 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 Topics
Replies: 11
Views: 157

Re: Test Topics

We won't have to draw VSEPR models, but we will most likely have to draw lewis structures and be able to label the VSEPR information.
by Matthew ILG 1L
Thu Nov 14, 2019 1:10 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angle
Replies: 9
Views: 68

Re: Bond Angle

When labeling the bonds in a trigonal pyramidal model are we allowed to say that it is 109.5 degrees or do we have to specify that it is slightly less than that?
by Matthew ILG 1L
Thu Nov 14, 2019 12:57 pm
Forum: Administrative Questions and Class Announcements
Topic: Test #2
Replies: 4
Views: 42

Re: Test #2

I assume we will need to know how to do Lewis Structures, which was taught before the midterm, in order to label VSEPR models. But other than that I am not sure how much we will need to know or study from before the midterm.
by Matthew ILG 1L
Thu Nov 14, 2019 12:12 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Arrangement vs Shape
Replies: 3
Views: 25

Re: Arrangement vs Shape

If "arrangement" is referring to the Lewis Structure and "shape" is referring to VSEPR model, then the arrangement is a 2-dimensional view of the molecular configuration, while the shape is a 3-dimensional model that has more specific angles.
by Matthew ILG 1L
Sun Nov 10, 2019 11:21 pm
Forum: Electronegativity
Topic: Atom size
Replies: 16
Views: 427

Re: Atom size

I don't believe that electronegativity and atomic radius are directly related. However, their trends are opposite, with the atomic radius increasing down and to the left and the electronegativity increasing up and to the right. It is a case of correlation without causation I believe.
by Matthew ILG 1L
Sat Nov 02, 2019 3:45 pm
Forum: General Science Questions
Topic: Can We Take The Final In Pencil?
Replies: 14
Views: 667

Re: Can We Take The Final In Pencil?

The syllabus says that only pens are allowed on tests. I have always used pencils for homework and other classes because I always am erasing things. But with a pen I have just started putting a large "x" over whatever I would normally erase.
by Matthew ILG 1L
Sat Nov 02, 2019 2:57 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Calculator rounding
Replies: 3
Views: 61

Re: Calculator rounding

What type of calculator are you using? Also if you are rounding during intermediate values during the equation process that may be a reason that you are ending with a rounded value.
by Matthew ILG 1L
Sat Nov 02, 2019 2:46 pm
Forum: Trends in The Periodic Table
Topic: Exceptions
Replies: 3
Views: 39

Re: Exceptions

The trends, such as electronegativity, atomic radius, and ionization energy, are typically very straight forward and have little to no exceptions.
by Matthew ILG 1L
Sat Nov 02, 2019 2:40 pm
Forum: Octet Exceptions
Topic: Expanded Valence Shells
Replies: 4
Views: 46

Re: Expanded Valence Shells

8 valence electrons is the limit for an element to hold in a given shell. If there are more than 8, then a new shell is formed.
by Matthew ILG 1L
Sat Nov 02, 2019 2:37 pm
Forum: Octet Exceptions
Topic: Exceptions?
Replies: 5
Views: 71

Re: Exceptions?

The way I learned in high school, the elements in third period and below are typically allowed to break the octet rule.
by Matthew ILG 1L
Sat Oct 26, 2019 11:27 pm
Forum: Resonance Structures
Topic: Bond lengths
Replies: 5
Views: 47

Re: Bond lengths

Bonds lengths are measured in angstroms, the stronger the bond, the shorter the lengths. The length will be given to us I believe, as was the case in Wednesday's lecture when the Dr. Lavelle stated in a slide "Observed N--O bond length in (NO3)- = 1.24 Angstroms. "
by Matthew ILG 1L
Sat Oct 26, 2019 11:15 pm
Forum: General Science Questions
Topic: Week 5 homework
Replies: 2
Views: 43

Re: Week 5 homework

For week 5, I was still doing some hw from the "quantum world" section. The problems seem to still be relevant with the notes, although I did do half of my problems on "chemical bonds" as well.
by Matthew ILG 1L
Sat Oct 26, 2019 11:10 pm
Forum: Lewis Structures
Topic: Reasoning for the octet
Replies: 3
Views: 48

Re: Reasoning for the octet

The reasoning for the octet rule that I learned in high school is that atoms "want" to be like the noble gases (He, Ne, Ar, Kr, Xe, Rn) and have 8 electrons in their outer shell, because electrons are most stable with a full outer shell.
by Matthew ILG 1L
Sat Oct 26, 2019 11:04 pm
Forum: Bond Lengths & Energies
Topic: Bond Lengths
Replies: 4
Views: 60

Re: Bond Lengths

An easy way I like to remember that double bonds are shorter and stronger than single bonds is I think of them as sticks. Longer, skinnier sticks are easier to break i.e. weaker bond. The shorter and wider the stick, or in our case, the bond (triple bond), the stronger it is.
by Matthew ILG 1L
Sat Oct 26, 2019 10:49 pm
Forum: Lewis Structures
Topic: Drawing the Lewis Structure
Replies: 2
Views: 41

Re: Drawing the Lewis Structure

The Lewis Structure should typically be symmetrical, with the singular element in the center.
by Matthew ILG 1L
Thu Oct 17, 2019 10:44 pm
Forum: Einstein Equation
Topic: unit of energy
Replies: 7
Views: 502

Re: unit of energy

I know the problem you're referring to. Its 1.B.5. You have to convert the 140.511keV to eV by multiplying it by 10^3, and then multiply the eV by 1.6022x10^-19J to find the J.
by Matthew ILG 1L
Thu Oct 17, 2019 8:46 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Drawing Orbitals
Replies: 5
Views: 64

Re: Drawing Orbitals

I have found in the past that drawing orbitals actually helps me understand the orbital levels better than just looking at it quantitatively. But there are others who would not benefit from drawing circles in a chemistry class.
by Matthew ILG 1L
Thu Oct 17, 2019 8:43 pm
Forum: *Shrodinger Equation
Topic: derivation
Replies: 5
Views: 63

Re: derivation

Having the equation sheet on the tests and quizzes, I would think that it is not too important to know how to derive the equations. There are many equations that are extremely complicated and time consuming to prove as well. I think that if Dr. Lavelle has proved the equation on the board during a l...

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