Search found 57 matches

by LeannaPhan14BDis1D
Tue Mar 05, 2019 7:22 pm
Forum: Zero Order Reactions
Topic: Half life
Replies: 5
Views: 49

Re: Half life

just for the 1st order reactions
by LeannaPhan14BDis1D
Tue Mar 05, 2019 7:19 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Delta n
Replies: 7
Views: 67

Re: Delta n

Destiny Diaz 4D wrote:so to find delta n you would take the moles from products subtracted from moles from reactants?

yes i think so?
by LeannaPhan14BDis1D
Tue Mar 05, 2019 7:18 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Determining Spontaneity
Replies: 7
Views: 286

Re: Determining Spontaneity

in general, you shouldn't assume anything in terms of spontaneity since it fluctuates with each reaction
by LeannaPhan14BDis1D
Tue Mar 05, 2019 7:15 pm
Forum: First Order Reactions
Topic: First Order Integrated Law
Replies: 3
Views: 20

Re: First Order Integrated Law

Yes they are the same thing.
by LeannaPhan14BDis1D
Tue Mar 05, 2019 7:14 pm
Forum: General Rate Laws
Topic: does k change if rxn is multiplied?
Replies: 6
Views: 39

Re: does k change if rxn is multiplied?

it shouldn't change when rxn is multiplied
by LeannaPhan14BDis1D
Tue Mar 05, 2019 7:13 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Finding Order for Each Reactant
Replies: 4
Views: 31

Re: Finding Order for Each Reactant

it doesn't seem like it should matter but i could easily be wrong
by LeannaPhan14BDis1D
Thu Feb 21, 2019 1:36 am
Forum: Van't Hoff Equation
Topic: ΔSº and ΔHº question
Replies: 5
Views: 44

Re: ΔSº and ΔHº question

Free energy is the one that changes and is influenced by temperature
by LeannaPhan14BDis1D
Thu Feb 21, 2019 1:34 am
Forum: Balancing Redox Reactions
Topic: Reducing agents and oxidizing agents
Replies: 6
Views: 37

Re: Reducing agents and oxidizing agents

Angela Cong 3C wrote:A simple acronym that helps to remember which is OIL RIG
OIL= Oxidation Is Loss (of electrons)
RIG= Reduction Is Gain (of electrons)

That's a really good way of memorizing it thank you
by LeannaPhan14BDis1D
Thu Feb 21, 2019 1:32 am
Forum: Ideal Gases
Topic: units
Replies: 15
Views: 97

Re: units

I did it too and the people above say it's bc k doesn't have units
by LeannaPhan14BDis1D
Thu Feb 21, 2019 1:31 am
Forum: Balancing Redox Reactions
Topic: Week 7 Homework
Replies: 15
Views: 97

Re: Week 7 Homework

He sent out an email saying thermodynamics and Gibbs free energy should be what we turn in
by LeannaPhan14BDis1D
Thu Feb 21, 2019 1:29 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible Reactions
Replies: 8
Views: 91

Re: Reversible Reactions

Will reversible reactions be on the next test?
by LeannaPhan14BDis1D
Thu Feb 21, 2019 1:27 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Reversible vs irreversible
Replies: 5
Views: 64

Re: Reversible vs irreversible

Reversible isn't that necessary to know since they're theoretical.
by LeannaPhan14BDis1D
Thu Feb 21, 2019 1:26 am
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isobaric
Replies: 11
Views: 101

Re: Isobaric

What would work most would be w= -pdeltav
by LeannaPhan14BDis1D
Thu Feb 21, 2019 1:25 am
Forum: Balancing Redox Reactions
Topic: H+ vs H3O+
Replies: 10
Views: 68

Re: H+ vs H3O+

It's best to use H+ even though it doesn't matter too much
by LeannaPhan14BDis1D
Fri Feb 01, 2019 10:09 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Surroundings
Replies: 11
Views: 62

Re: Surroundings

the surroundings is just a broad concept and depending on what is being talked about the "surroundings" could be infinite to the universe and yet be any small part in the universe as well.
by LeannaPhan14BDis1D
Fri Feb 01, 2019 10:07 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: closed vs isolated
Replies: 14
Views: 141

Re: closed vs isolated

a closed system is capable of influence with outer environments and variables while an isolated system cannot be changed whatsoever.
by LeannaPhan14BDis1D
Fri Feb 01, 2019 10:04 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Heat vs. Temp
Replies: 9
Views: 193

Re: Heat vs. Temp

In short, heat is energy while temperature itself is not and it measures the speed of the molecules moving about.
by LeannaPhan14BDis1D
Sat Jan 26, 2019 9:50 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: q vs. qp
Replies: 2
Views: 28

Re: q vs. qp

They both are essentially the same I believe but q with a p subscript means it's processed under constant pressure like the other person said.
by LeannaPhan14BDis1D
Sat Jan 26, 2019 9:43 pm
Forum: Phase Changes & Related Calculations
Topic: Due date for Discussion Questions
Replies: 8
Views: 86

Re: Due date for Discussion Questions

and last quarter with lavelle the forum posts are due every sunday and I'm sure it is the same for this quarter.
by LeannaPhan14BDis1D
Sat Jan 19, 2019 6:48 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ignoring solids
Replies: 6
Views: 56

Re: ignoring solids

In the endgame result for K or Q solids and pure liquids will not affect the results.
by LeannaPhan14BDis1D
Sat Jan 19, 2019 6:46 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Example in class
Replies: 5
Views: 51

Re: Example in class

for the example he gave, he used Q since the equation wasn't at equilibrium
by LeannaPhan14BDis1D
Sat Jan 19, 2019 6:44 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: How to tell if a chemical is an acid or base?
Replies: 4
Views: 55

Re: How to tell if a chemical is an acid or base?

For the most part you will kinda just have to memorize whether or not it is a base or an acid
by LeannaPhan14BDis1D
Fri Jan 11, 2019 3:18 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Exothermic Reactions
Replies: 9
Views: 93

Re: Exothermic Reactions

IN the lecture today he wrote/ said
when pressure changes
when k does change
If rxn requires heat (endothermic) while forming product then heating will favor P formation.
If rxn gives off heat (exothermic) while forming product then heating will favor R formation.
hope this helps :)
by LeannaPhan14BDis1D
Fri Jan 11, 2019 3:16 pm
Forum: Ideal Gases
Topic: Units
Replies: 19
Views: 167

Re: Units

Lavelle said due to the absolute 0 K we use Kelvin like the other people said
by LeannaPhan14BDis1D
Fri Jan 11, 2019 3:14 pm
Forum: Ideal Gases
Topic: What does K represent?
Replies: 9
Views: 87

Re: What does K represent?

K is a constant but it is supposed to stay the same regardless of the different P/R right?
by LeannaPhan14BDis1D
Sat Dec 08, 2018 5:18 pm
Forum: Administrative Questions and Class Announcements
Topic: How to find my posts
Replies: 28
Views: 15565

Re: How to find my posts

the quick links tab works best for me and it gives you the number of posts you put up and the comments people wrote after you.
by LeannaPhan14BDis1D
Sat Dec 08, 2018 5:16 pm
Forum: Administrative Questions and Class Announcements
Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Replies: 118
Views: 4127

Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]

this was really helpful and so was the review session thank you!
by LeannaPhan14BDis1D
Fri Nov 30, 2018 3:46 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain on the Final
Replies: 4
Views: 82

Re: Acid Rain on the Final

It is most likely going to be covered on the final but that is dependent on whether or not we get it covered next week before the test.
by LeannaPhan14BDis1D
Fri Nov 30, 2018 3:44 pm
Forum: Lewis Acids & Bases
Topic: Strength
Replies: 3
Views: 32

Re: Strength

The easier it is to dissociate into H+ and OH-, the weaker the acid or base is.
by LeannaPhan14BDis1D
Fri Nov 30, 2018 3:39 pm
Forum: General Science Questions
Topic: Final Review
Replies: 4
Views: 98

Re: Final Review

It mainly depends on what you believe you need most help in. If you understand all of the topics and just want to concrete your knowledge go to the one you are most confident in to see if you missed anything. Go to the step ups if you are struggling with a topic too.
by LeannaPhan14BDis1D
Fri Nov 23, 2018 5:51 pm
Forum: Sigma & Pi Bonds
Topic: Drawing bonds
Replies: 3
Views: 75

Re: Drawing bonds

I mean it is possible he would put it on but I'd refer to the outlines for test 3 he put up.
by LeannaPhan14BDis1D
Fri Nov 23, 2018 5:49 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Position of atoms in Trigonal Planar
Replies: 4
Views: 48

Re: Position of atoms in Trigonal Planar

This applies to the angles?
by LeannaPhan14BDis1D
Tue Nov 20, 2018 6:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanksgiving Wednesday Class
Replies: 19
Views: 276

Re: Thanksgiving Wednesday Class

Chem_Mod wrote:All discussions will happen on Wednesday as usual.
All students should turn in homework for week 8 and 9 during week 9 discussion. This means you need 14 homework problems next week.


So for this weeks discussion we do not need to turn in week 8 homework?
by LeannaPhan14BDis1D
Sat Nov 17, 2018 4:03 am
Forum: Hybridization
Topic: Test 3
Replies: 5
Views: 113

Re: Test 3

I think it is just the molecular shapes and structure from those outlines
by LeannaPhan14BDis1D
Sat Nov 17, 2018 4:01 am
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR- Polar vs Nonpolar
Replies: 5
Views: 45

Re: VSEPR- Polar vs Nonpolar

are there any more exceptions to the rule of polar and nonpolar with the vespr?
by LeannaPhan14BDis1D
Sat Nov 17, 2018 3:59 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Sigma and Pi Bonds
Replies: 2
Views: 43

Re: Sigma and Pi Bonds

double bonds = one pi bond + one sigma bond
triple bonds = one sigma bond + two pi bonds
this is all i know
by LeannaPhan14BDis1D
Fri Nov 09, 2018 9:21 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: T-Shape
Replies: 6
Views: 176

Re: T-Shape

When we put the angles being 90 and 120 it is mainly a ballpark answer unless you calculated it being on the dot. it is around 90 or slightly less than 90.
by LeannaPhan14BDis1D
Fri Nov 09, 2018 9:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: HW for discussion
Replies: 9
Views: 174

Re: HW for discussion

I am sure you can due the easier ones on outline 4 since we went over shapes and angles too.
by LeannaPhan14BDis1D
Fri Nov 09, 2018 9:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Shape
Replies: 4
Views: 50

Re: Molecular Shape

is there any other challenging molecule someone can provide as an example to help further help with my knowledge on how the shapes and angles work?
by LeannaPhan14BDis1D
Fri Nov 02, 2018 12:26 am
Forum: Octet Exceptions
Topic: octet rule exceptions?
Replies: 5
Views: 75

Re: octet rule exceptions?

Is there a way to figure out which ones are allowed to contradict the octet rule or is it all of the ones from 3 and down.??
by LeannaPhan14BDis1D
Fri Nov 02, 2018 12:19 am
Forum: Resonance Structures
Topic: Tricks for Resonance Structures
Replies: 5
Views: 123

Tricks for Resonance Structures

Are there any simple tricks to seeing how many resonance structures there could be for a single compound? What about for the resonance structures with formal charge that is not 0, would we have to include all the structures or do we exclude a certain number of formal charge when making resonance str...
by LeannaPhan14BDis1D
Fri Nov 02, 2018 12:14 am
Forum: Lewis Structures
Topic: Drawing Lewis Structures
Replies: 14
Views: 233

Re: Drawing Lewis Structures

If the angles are determined by something we haven't gone over will we be tested and graded on specificity of our structures with those angles or will it not matter as much for this midterm.
by LeannaPhan14BDis1D
Thu Oct 25, 2018 11:48 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Exceptions [ENDORSED]
Replies: 3
Views: 78

Re: Electron Configuration Exceptions [ENDORSED]

It has something to do with the stability of the element and how it likes a specific configuration. The sublevels when they are completely filled are more stable than those that are partially filled. Sorry this is a kind of convoluted explanation but it is the only one I have. I hope more people can...
by LeannaPhan14BDis1D
Thu Oct 25, 2018 11:42 pm
Forum: Einstein Equation
Topic: Units
Replies: 6
Views: 153

Re: Units

What equation do you mean? is there a specific equation you are referring to? The test requires you to answer with correct units and sig figs. I do not believe that they give you the units.
by LeannaPhan14BDis1D
Thu Oct 25, 2018 11:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Exam
Replies: 2
Views: 98

Re: Exam

You have to know its function and how it can be applied.
by LeannaPhan14BDis1D
Thu Oct 18, 2018 11:47 pm
Forum: Properties of Light
Topic: calculating wavelength
Replies: 10
Views: 278

Re: calculating wavelength

Dr. Lavelle mentioned that E = hv can only be used for light. However, De Broglie's equation of lambda=h/p can only be used for objects with "rest" mass and velocity. "Rest" mass basically means anything that has mass when stationary. why is rest in quotes.. is there a significa...
by LeannaPhan14BDis1D
Thu Oct 18, 2018 11:28 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: angular nodes
Replies: 1
Views: 42

angular nodes

Why is it that when you have an angular node the wave function changes sign?
by LeannaPhan14BDis1D
Thu Oct 18, 2018 11:21 pm
Forum: Ionic & Covalent Bonds
Topic: Electron Configuratin
Replies: 5
Views: 92

Re: Electron Configuratin

I would think it is due to the s orbitals having lower energy, but this is a very good question. Now that I think about it I do not understand it either...
by LeannaPhan14BDis1D
Thu Oct 11, 2018 10:48 pm
Forum: Properties of Light
Topic: How light behaves
Replies: 8
Views: 147

How light behaves

I cannot conceptualize light being both photon (PACKETS) of energy and wavelengths. I find it difficult to exercise this into equations when I do not understand how it can be both and have one number. Please explain and possibly use equations in your explanation if possible. If not that is okay, any...
by LeannaPhan14BDis1D
Thu Oct 11, 2018 10:26 pm
Forum: Quantum Numbers and The H-Atom
Topic: H-Atom
Replies: 1
Views: 42

H-Atom

In the atomic spectra model, the hydrogen atoms are ideally in a vacuum and then there comes a white light going through it. This makes the hydrogen excited and this is where I get foggy. Does the hydrogen become an isotope giving off an electron into the air and then coming back together after the ...
by LeannaPhan14BDis1D
Thu Oct 11, 2018 10:11 pm
Forum: Photoelectric Effect
Topic: Confused conceptually with photoelectric effect
Replies: 3
Views: 69

Confused conceptually with photoelectric effect

I do not understand when Lavelle spoke on the length of the wavelength and how it ejects electrons. Please advice since the reading makes it only slightly less confusing. I get how the shorter the wavelength is it will eject more electrons, but I do not understand how. Thank you.
by LeannaPhan14BDis1D
Wed Oct 03, 2018 11:00 pm
Forum: Balancing Chemical Reactions
Topic: Extensive v. Intensive Property [ENDORSED]
Replies: 6
Views: 166

Extensive v. Intensive Property [ENDORSED]

I am not sure I understand the complete difference between Extensive v. Intensive Property. Please send as many examples as possible.
by LeannaPhan14BDis1D
Wed Oct 03, 2018 10:32 pm
Forum: Molarity, Solutions, Dilutions
Topic: Question G23
Replies: 3
Views: 74

Re: Question G23

For most of the problems in the set, you need to just start by changing the mass to moles. In this problem add to get the total number of moles of ions after and then divide over the volume given. After that you will get the molarity. :)
by LeannaPhan14BDis1D
Wed Oct 03, 2018 10:24 pm
Forum: Balancing Chemical Reactions
Topic: Concept Question for #M15
Replies: 2
Views: 62

Concept Question for #M15

When doing stoichiometry (7.55molCl2)*(2mol AlCl3/3mol Cl2) = 5.03 mol AlCl3 -- the limiting reactant I know how to get to the answer, but I am confused conceptually as to why when you already have the mol for AlCl3 and the stoichiometric coefficient being 2.. why do we need to do more towards it to...

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