Search found 63 matches

by Maria Solis Disc 1G
Fri Mar 15, 2019 11:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Deriving
Replies: 3
Views: 142

Re: Deriving

If you really want to study this, if you read the book theres yellow sections called How to do, or somethig like that, and it explains step by step the derivations and connections between topics.
by Maria Solis Disc 1G
Fri Mar 15, 2019 11:03 pm
Forum: General Rate Laws
Topic: rate laws
Replies: 6
Views: 76

Re: rate laws

I was told by my PLF that they are used only for elementary step rate laws
by Maria Solis Disc 1G
Fri Mar 15, 2019 11:00 pm
Forum: Administrative Questions and Class Announcements
Topic: Approximation & Cubic Equations on Final
Replies: 2
Views: 140

Re: Approximation & Cubic Equations on Final

Considering he didn't mention it, I assume it's fair game to include both.
by Maria Solis Disc 1G
Fri Mar 15, 2019 11:00 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: delta U
Replies: 4
Views: 138

Re: delta U

Internal Energy should always be q+w
by Maria Solis Disc 1G
Fri Mar 15, 2019 10:48 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: kr
Replies: 1
Views: 102

Re: kr

Chem_Mod Re: Disregard liquid and solid reactants in rate law? "That is correct. As for water, water or any other molecule that is not the solvent, if it is part of a reaction, it can be in the rate law. However if the solvent is water, you do not include water in the rate law since you have ex...
by Maria Solis Disc 1G
Fri Mar 15, 2019 10:42 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isometric/Isochoric
Replies: 10
Views: 191

Re: Isometric/Isochoric

In the book, it says that bomb calorimeters are usually metals, so they maintain the volume although pressure may increase. To make the bomb calorimeter an isolated system, it can also be submerged in water to make it isothermal.
by Maria Solis Disc 1G
Fri Mar 15, 2019 10:37 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts
Replies: 4
Views: 74

Re: Catalysts

No, since they are not part of the actual reaction.
by Maria Solis Disc 1G
Fri Mar 15, 2019 10:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equillibrium Constant
Replies: 1
Views: 43

Equillibrium Constant

In the book I read that the equilibrium constant is changed if the reaction is changed by a multiple ( such as NH3 to 2NH3). How would the constant change? Also how would we find the Equilibrium constant if multiple reactions ( and their K values are given) but not the overall reaction.
by Maria Solis Disc 1G
Fri Mar 15, 2019 10:26 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: What are the units for A?
Replies: 1
Views: 44

Re: What are the units for A?

I searched this up online, and it said the units for A are the same as the rate constant units. In other words the units of A depend on the rxn order.
by Maria Solis Disc 1G
Fri Mar 15, 2019 10:18 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Deriving
Replies: 3
Views: 61

Re: Deriving

Considering it is moderately simple to derive, I would memorize how to derive the equations just in case.
by Maria Solis Disc 1G
Fri Mar 15, 2019 10:14 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Catalysts
Replies: 2
Views: 44

Re: Catalysts

Catalysts show up in the beginning of the reaction and at the end. The substances that are consumed are called intermediates.
by Maria Solis Disc 1G
Fri Mar 15, 2019 10:09 pm
Forum: Student Social/Study Group
Topic: class pictures
Replies: 15
Views: 950

Re: class pictures

Here is a video, not the best quality though.
by Maria Solis Disc 1G
Sun Mar 10, 2019 7:56 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Temperature
Replies: 1
Views: 38

Temperature

When doing calculations and temperature isn't given, can we assume standard condition. What is standard condition, beside being at room temperature?
by Maria Solis Disc 1G
Sun Mar 10, 2019 7:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell diagram
Replies: 6
Views: 83

Cell diagram

When drawing a cell diagram, why is platinum or carbon i belive included in the diagram if it is not involved in the actual reaction.
by Maria Solis Disc 1G
Sun Mar 10, 2019 7:47 pm
Forum: Balancing Redox Reactions
Topic: Oxidation vs Reduction Half Rxn
Replies: 9
Views: 108

Re: Oxidation vs Reduction Half Rxn

Oxidation releases electrons (on right side of equation), reduction uses electrons (on left side of equation) in short terms.
by Maria Solis Disc 1G
Fri Feb 08, 2019 5:55 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: Residual Entropy
Replies: 5
Views: 100

Re: Residual Entropy

I honestly do not know what residual entropy is, but Dr. Lavelle mentioned rotational state, translational state, vibrational state, and an electron's state in the actual atom.
by Maria Solis Disc 1G
Fri Feb 08, 2019 5:53 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Temperature and Entropy
Replies: 1
Views: 47

Temperature and Entropy

During lecture today it was said that as temperature increases, thermal motion increases, meaning that entropy increases. Using the equation S=q/T it is implied that entropy is inversely proportional to entropy. Can anyone explain this please?
by Maria Solis Disc 1G
Fri Feb 08, 2019 5:48 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Entropy, Enthalpy, Free Energy.
Replies: 2
Views: 65

Re: Entropy, Enthalpy, Free Energy.

entropy is q(reversible)/T. q(p=reversible)= delta H (enthalpy) if pressure is constant.
by Maria Solis Disc 1G
Sun Feb 03, 2019 8:02 pm
Forum: Calculating Work of Expansion
Topic: Varieties of Work (Table 4A.1 (7th Edition))
Replies: 1
Views: 43

Re: Varieties of Work (Table 4A.1 (7th Edition))

The methods we've used so far seem to be only on expansion. So for now we should only be required to know those theoretically.
by Maria Solis Disc 1G
Sun Feb 03, 2019 7:58 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Calorimeters
Replies: 2
Views: 64

Calorimeters

Can someone explain the different types of calorimeters there are. I am lost on how to recognize what calorimeter to use and how to solve these types of problems.
by Maria Solis Disc 1G
Sun Feb 03, 2019 7:56 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Recognizing delta u
Replies: 2
Views: 54

Recognizing delta u

While doing a problem how would we recognize what method to use. Like how would we know if we need to use delta u.
by Maria Solis Disc 1G
Fri Jan 25, 2019 4:43 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ignoring x
Replies: 10
Views: 131

Re: ignoring x

I was also told that you HAVE TO check the 5% rule, you cant just choose if you want to check. It's better to be safe than sorry.
by Maria Solis Disc 1G
Fri Jan 25, 2019 4:40 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Accurate and estimation of bond enthalpy
Replies: 3
Views: 61

Accurate and estimation of bond enthalpy

During class today Dr Lavelle stated that all diatomic molecules bond enthalpies were accurate, and that all other bond enthalpies were averages. I was wondering if someone could explain what a diatomic molecule was. I also vaguely remember Dr. Lavelle stating that C2's bond enthalpy is composed of ...
by Maria Solis Disc 1G
Fri Jan 25, 2019 4:20 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 6th edition, 4A3 pt c
Replies: 2
Views: 64

Re: 6th edition, 4A3 pt c

I was told by my T.A. that the 7th edition has more errors than the 6th. This has also happened to me, and the 7th edition is the one that tends to be wrong.
by Maria Solis Disc 1G
Tue Jan 22, 2019 1:12 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Test and acid/ base recognition
Replies: 1
Views: 51

Test and acid/ base recognition

On this weeks test, will we need to know what acids/bases are strong/weak out of memory, or will we be told or be given a Ka/ Kb.
by Maria Solis Disc 1G
Tue Jan 22, 2019 1:08 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature change
Replies: 5
Views: 94

Temperature change

I know that when you change a rxn's condition the reaction is moved from equilibrium, but I was wondering how an increase or decrease in temperature specifically effected a reaction.
by Maria Solis Disc 1G
Tue Jan 22, 2019 1:03 am
Forum: Ideal Gases
Topic: ICE Table Values
Replies: 9
Views: 224

Re: ICE Table Values

The ice table is used for finding out how much of a weak acid or base reacted. From the problems I've seen only bars and molarity were used, but I'm not completely positive.
by Maria Solis Disc 1G
Sun Jan 13, 2019 11:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Actual Yield of Products
Replies: 2
Views: 41

Re: Actual Yield of Products

I don't believe that a reaction goes to completion if you keep adding reactants. On the contrary the reaction will keep shifting. I am not completely sure though.
by Maria Solis Disc 1G
Sun Jan 13, 2019 11:43 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 7
Views: 78

Re: Le Chatelier's Principle

In short the reaction shifts to accommodate a change in the reaction. Such as a change in temperature or concentration.
by Maria Solis Disc 1G
Sun Jan 13, 2019 11:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pure Solids and Liquids
Replies: 2
Views: 34

Pure Solids and Liquids

I'm slightly confused on how to identify a pure solid and liquid when looking a written reaction. Can anyone please explain how to identify these.
by Maria Solis Disc 1G
Sun Dec 02, 2018 11:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Grades
Replies: 10
Views: 225

Re: Final Grades

Yeah I know that but like overall letter grade is what I'm asking.
by Maria Solis Disc 1G
Sun Dec 02, 2018 11:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 2
Views: 47

Re: Ligands

A ligand is just an ion/ molecule that is bonded to the central atom. You basically figure them out using the lewis structure I believe.
by Maria Solis Disc 1G
Sun Dec 02, 2018 11:41 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Calculating
Replies: 2
Views: 65

Re: Calculating

Dr. lavelle went over it really briefly and said that ph=-log10[h30].
by Maria Solis Disc 1G
Sun Dec 02, 2018 11:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Grades
Replies: 10
Views: 225

Final Grades

Hey so does anyone know how the grading in this class is done. Is the class curved or is there a specific rubric. I've been asking around but still can't seem to find out.
by Maria Solis Disc 1G
Sun Nov 25, 2018 10:58 pm
Forum: Hybridization
Topic: Questions in Chapter
Replies: 5
Views: 84

Questions in Chapter

For some of the questions from this chapter, in the textbook, they give the names of molecules rather than formulas in the questions. For test 3 will we be expected to know any basic molecules yet by the name.
by Maria Solis Disc 1G
Sun Nov 25, 2018 10:48 pm
Forum: Photoelectric Effect
Topic: Midterm Q3B
Replies: 1
Views: 199

Re: Midterm Q3B

First I used the equation E=hv to find the energy of a photon. Then I used the kinetic energy equation E=(1/2)mv^2 to find the energy of a electron that is released. Then using the concept of conservation of energy I set the initial energy of a photon equal to the sum of the Ionization energy (AKA t...
by Maria Solis Disc 1G
Sun Nov 25, 2018 10:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Unhybridized P orbital
Replies: 2
Views: 34

Unhybridized P orbital

In one of Dr. Lavelle's lectures he mentioned how a p orbital was left unhybridized. Can anyone explain this to me, and also would this unhybridized p orbital also contain electrons or not?
by Maria Solis Disc 1G
Mon Nov 19, 2018 8:50 pm
Forum: Hybridization
Topic: Hybridized Orbitals
Replies: 4
Views: 72

Re: Hybridized Orbitals

If you look at the atoms normal electron configuration, it may be inaccurate to the number of bonds that the atom has in a certain molecule. The hybridized d must be included if a atom has more than 4 bonds (8 electrons), such as those that exceed the octet rule.
by Maria Solis Disc 1G
Mon Nov 19, 2018 8:45 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular shape on test
Replies: 5
Views: 95

Molecular shape on test

For the final, and test 3, will we be expected to know how to draw molecules, using electron densities (including the hybridized and non-hybridized models).
by Maria Solis Disc 1G
Mon Nov 19, 2018 8:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining bond type
Replies: 4
Views: 73

Re: Determining bond type

From my understanding, as of so far, there is always one sigma bond between two atoms and the rest are pi bonds between those same atoms.
by Maria Solis Disc 1G
Sun Nov 11, 2018 12:00 am
Forum: Electronegativity
Topic: Electronegativity and Electron Affinity
Replies: 4
Views: 135

Re: Electronegativity and Electron Affinity

I'm honestly quite lost also but what i found online says that electron affinity is an experimentally measured value, while eletronegativity is given in relationship to the values of other atoms in the periodic table
by Maria Solis Disc 1G
Sat Nov 10, 2018 11:46 pm
Forum: Dipole Moments
Topic: Polarity and Dipole moments
Replies: 2
Views: 77

Re: Polarity and Dipole moments

The overall polarity of a molecule can be considered the vector additions of the all the dipole moments. they can either cancel each other out or add up.
by Maria Solis Disc 1G
Sat Nov 10, 2018 11:35 pm
Forum: Ionic & Covalent Bonds
Topic: delta positive delta negative
Replies: 15
Views: 339

Re: delta positive delta negative

First draw the direction of the dipole. The dipole should point towards the more electronegative atom in a molecule. therefore the end that the dipole points at is delta negative, and the end where the dipole starts at is delta positive. It may be confusing but try drawing it out, it'll help.
by Maria Solis Disc 1G
Sun Nov 04, 2018 12:32 pm
Forum: Bond Lengths & Energies
Topic: Bond order
Replies: 4
Views: 87

Re: Bond order

I am not completely positive but i believe bond order is the average bond length of the resonance hybrid. I am almost positive though that to calculate bond order you divide all the number of bonds between the central and outer atoms (sticks)and divide by the number of outer atoms that you used.
by Maria Solis Disc 1G
Sun Nov 04, 2018 12:26 pm
Forum: Lewis Structures
Topic: Question 3.55 (Sixth Edition)
Replies: 6
Views: 96

Re: Question 3.55 (Sixth Edition)

When you draw the lewis structures other of the answers given also seem to be radicals.
by Maria Solis Disc 1G
Sun Nov 04, 2018 12:25 pm
Forum: Lewis Structures
Topic: Question 3.55 (Sixth Edition)
Replies: 6
Views: 96

Re: Question 3.55 (Sixth Edition)

A radical is basically a molecule that has more than one unpaired electron. In this case the answer is OH since there can only be a single bond in OH, O must have 5 electrons, resulting in one being unpaired.
by Maria Solis Disc 1G
Sun Nov 04, 2018 12:17 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron configuration when 4s and 3d
Replies: 3
Views: 51

Re: Electron configuration when 4s and 3d

From my understanding you fill the 4s before the 3d usually. Only when the 3d is an exception, such as when you are 1 e from completing the 3 d orbital, do you complete the 3d first, since youre ultimate goal is to get a more stable atom. But when you write down the electron configurations first mak...
by Maria Solis Disc 1G
Sun Oct 28, 2018 7:32 pm
Forum: Ionic & Covalent Bonds
Topic: Polyatomic Ions [ENDORSED]
Replies: 4
Views: 126

Re: Polyatomic Ions [ENDORSED]

At the beginning of the quarter Dr. Lavelle said we didn't have to know them now, but that later we would. My PLF also said that with time, after doing many problems, you would probably end up memorizing them anyways. Don't worry about it too much , but do try to memorize them.
by Maria Solis Disc 1G
Sun Oct 28, 2018 7:23 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 1E 25)
Replies: 2
Views: 61

Re: 1E 25)

I would assume that we would need to know the basic groups, just because it was covered in high school chem. It's better to be safe than sorry, so I'd say just memorize the groups. On one slide though, the one where the periodic table is color coated in 3 different colors, where I believe he did men...
by Maria Solis Disc 1G
Sun Oct 28, 2018 6:00 pm
Forum: Administrative Questions and Class Announcements
Topic: Peer learning Sessions
Replies: 3
Views: 108

Re: Peer learning Sessions

The peer learning that I am aware of is the one that AAP offers. To join that one, you have to be a part of AAP, but i also did a google search and found this https://www.lscore.ucla.edu/ls-core-peer-learning/ . If you aren't a part of AAP you can investigate the one that this page offers.
by Maria Solis Disc 1G
Sun Oct 21, 2018 8:24 pm
Forum: Properties of Electrons
Topic: ml
Replies: 5
Views: 146

ml

On Friday's lecture Dr. Lavelle kept mentiong ml, can someone please explain what that is, as I am majorly lost. Also instead of doing a lowercase l can i use a cursive l, since one of the reasons i got lost was because i kept confusing the l with a 1.
by Maria Solis Disc 1G
Sun Oct 21, 2018 8:17 pm
Forum: Properties of Electrons
Topic: Shortcuts
Replies: 4
Views: 206

Shortcuts

So I'm having a hard time remembering the electron configurations, such as as the orbital shapes. I was wondering if anyone had a shortcut or method of memorizing these.
by Maria Solis Disc 1G
Sun Oct 21, 2018 8:11 pm
Forum: DeBroglie Equation
Topic: Remembering mass of electrons for tests
Replies: 6
Views: 137

Re: Remembering mass of electrons for tests

I assume we wouldn't, just because on the last exam we were given known values.
by Maria Solis Disc 1G
Wed Oct 17, 2018 12:29 am
Forum: Administrative Questions and Class Announcements
Topic: Points
Replies: 4
Views: 99

Re: Points

Alright Thank You!!!! Also I'm almost certain that you cannot make up for a previous week, because what i do remember is Dr. Lavelle saying the max number of points per week was 3.
by Maria Solis Disc 1G
Tue Oct 16, 2018 5:17 pm
Forum: Properties of Electrons
Topic: Detectable Electron Wavelength
Replies: 2
Views: 64

Re: Detectable Electron Wavelength

In the lecture the professor said that gammas rays were the lowest, for sure, measured wavelength at 10^-12, but that anything below 10^-15 was unlikely, and that anything below 10^-18 was undetectable. He said that on the quizzes and test though, the answers were going to be obviously small, at aro...
by Maria Solis Disc 1G
Tue Oct 16, 2018 5:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Points
Replies: 4
Views: 99

Points

Would posting 3 times in a single day count towards the 3 posts per week that i must submit.
by Maria Solis Disc 1G
Mon Oct 15, 2018 2:27 am
Forum: Student Social/Study Group
Topic: Percent Composition
Replies: 3
Views: 225

Re: Percent Composition

When I was doing one of these questions myself the number wasn't adding up to 100%. Although significant figures may have caused you to get to 99% you can try truncating all your answers to see if you get 100%, if you rounded all your answers.
by Maria Solis Disc 1G
Mon Oct 15, 2018 2:13 am
Forum: Properties of Light
Topic: Measurable Wavelengths
Replies: 3
Views: 41

Re: Measurable Wavelengths

Although Dr. Lavelle said the cutoff was 10 ^-18, he specifically said that we wouldnt have to worry about the cutoff since the answers would be obviously small, like 10^-30
by Maria Solis Disc 1G
Mon Oct 15, 2018 1:59 am
Forum: Student Social/Study Group
Topic: Studying techniques
Replies: 12
Views: 254

Re: Studying techniques

It all depends on the person. What works best for me is either rewiting notes in different colors, which helps me remember things better, or even making a little song out of the study notes. You can also try flashcards!
by Maria Solis Disc 1G
Mon Oct 15, 2018 1:57 am
Forum: Administrative Questions and Class Announcements
Topic: Writing in Pen
Replies: 13
Views: 295

Re: Writing in Pen

You should definitely ask your TA. My TA for instance told us she didn't mind if we wrote with pencil. But its all up to the TA I guess.
by Maria Solis Disc 1G
Mon Oct 08, 2018 6:08 pm
Forum: Properties of Light
Topic: Speed of light constant (c)
Replies: 6
Views: 102

Re: Speed of light constant (c)

I remember the professor mentioning that the real value was the one starting with 2.99, but that for convenience he used the one starting with 3.00.
by Maria Solis Disc 1G
Mon Oct 08, 2018 6:05 pm
Forum: Empirical & Molecular Formulas
Topic: M19
Replies: 3
Views: 157

Re: M19

If you're talking about the homework problem it should give you the molar mass of caffeine, and the percent composition. so you would multiply each percentage by the total molar mass. I don't think we should be expected to know the formula for caffeine, considering it's so early in the year.
by Maria Solis Disc 1G
Mon Oct 08, 2018 5:59 pm
Forum: Empirical & Molecular Formulas
Topic: when to multiply empirical formula [ENDORSED]
Replies: 9
Views: 385

Re: when to multiply empirical formula [ENDORSED]

You would multiple all the coefficients by 7, since you can't have 3.5 as a coefficient. You can't use 3 or 4 because that wouldn't uphold the exact proportion of 3.5.

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