Search found 62 matches

by Sheridan Slaterbeck 1J
Sun Mar 10, 2019 11:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Final Exam
Replies: 23
Views: 240

Re: Final Exam

Yes anything we learned this quarter could be on it.
by Sheridan Slaterbeck 1J
Sun Mar 10, 2019 11:24 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Test 2
Replies: 12
Views: 192

Re: Test 2

delta G is negative as a combustion will increase the entropy S, or disorder, of the system and is therefore spontaneous.
by Sheridan Slaterbeck 1J
Sun Mar 10, 2019 11:22 pm
Forum: Second Order Reactions
Topic: Final
Replies: 30
Views: 441

Re: Final

It should be anything that we learned this quarter, cumulative.
by Sheridan Slaterbeck 1J
Sun Mar 03, 2019 8:20 pm
Forum: Balancing Redox Reactions
Topic: Strength of reducing agent
Replies: 10
Views: 190

Re: Strength of reducing agent

The more negative the E, the more strong it is as a reducing agent (the thing being oxidized). Another way of saying it is a good donator.
by Sheridan Slaterbeck 1J
Sun Mar 03, 2019 8:12 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Melting of ice
Replies: 9
Views: 167

Re: Melting of ice

a solid to a liquid would be a spontaneous reaction so delta G would be negative.
by Sheridan Slaterbeck 1J
Sun Feb 24, 2019 10:15 pm
Forum: Student Social/Study Group
Topic: Test
Replies: 17
Views: 356

Re: Test

Thermodynamics and electrochemistry up to nerst equation.
by Sheridan Slaterbeck 1J
Sun Feb 24, 2019 10:13 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous?
Replies: 13
Views: 142

Re: Spontaneous?

When delta G is negative it is exergonic and when it is positive it is endergonic
when delta H is negative it is exothermic and when it is positive it is endothermic.
by Sheridan Slaterbeck 1J
Sun Feb 24, 2019 10:12 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Spontaneous?
Replies: 13
Views: 142

Re: Spontaneous?

It is spontaneous if delta G is negative, if (-TdeltaS) is negative, if deltaS is positive, and if delta H is negative
delta G = deltaH -TdeltaS
by Sheridan Slaterbeck 1J
Mon Feb 18, 2019 12:00 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: HW for W7
Replies: 7
Views: 104

Re: HW for W7

Chapter 9 questions I believe
by Sheridan Slaterbeck 1J
Sun Feb 17, 2019 11:59 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Midterm Grades
Replies: 35
Views: 603

Re: Midterm Grades

My TA said by friday of this upcoming week
by Sheridan Slaterbeck 1J
Sun Feb 17, 2019 11:57 pm
Forum: Student Social/Study Group
Topic: Best Midterm Review
Replies: 7
Views: 140

Re: Best Midterm Review

peer learning sessions will break down fewer problems but go slowly and more in depth, a chance to ask more questions
Midterm reviews cover more problems but go really fast and get less explanation , more for practice if you already understand the topic.
by Sheridan Slaterbeck 1J
Sun Feb 17, 2019 11:56 pm
Forum: Student Social/Study Group
Topic: Test
Replies: 17
Views: 356

Re: Test

My TA said majority of it will be thermodynamics
by Sheridan Slaterbeck 1J
Sun Feb 10, 2019 11:01 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: deltaS=nCvln(t2/t1) what is Cv?
Replies: 7
Views: 125

Re: deltaS=nCvln(t2/t1) what is Cv?

when would you use deltaS=nRln(V2/v1) ?
by Sheridan Slaterbeck 1J
Sun Feb 10, 2019 10:57 pm
Forum: Ideal Gases
Topic: ICE Table Values
Replies: 9
Views: 239

Re: ICE Table Values

I would say look to see what the problem gives you if Kc then use concentration values (mol/L). If "K" or Kp then use partial pressure (bars).
by Sheridan Slaterbeck 1J
Sun Feb 10, 2019 10:53 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: conversions
Replies: 3
Views: 56

Re: conversions

I would a assume they would give us that conversion if we needed it.
by Sheridan Slaterbeck 1J
Sun Feb 10, 2019 10:52 pm
Forum: Phase Changes & Related Calculations
Topic: Heat vs Q
Replies: 5
Views: 56

Re: Heat vs Q

If it asked for change in enthalpy you would solve for deltaH. If it is asking for heat occurring by the system or on the system solve for q.
by Sheridan Slaterbeck 1J
Sun Feb 10, 2019 10:50 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: answer format
Replies: 4
Views: 73

Re: answer format

I would say convert it to joules just in case if they don't specify
by Sheridan Slaterbeck 1J
Sun Feb 10, 2019 10:49 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isochoric
Replies: 3
Views: 72

Re: Isochoric

if V=0
w=-Pext delta V
w=-P(0) so work =0
by Sheridan Slaterbeck 1J
Sun Feb 03, 2019 11:27 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: deriving the work equation: -P*deltaV
Replies: 2
Views: 49

Re: deriving the work equation: -P*deltaV

I don't think so Lavelle usually just shows derivatives as a way of understanding where the equations came from.
by Sheridan Slaterbeck 1J
Sun Feb 03, 2019 11:25 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed Systems
Replies: 6
Views: 69

Re: Closed Systems

An example of isolated system would be soup in an insulated container (assuming insulation is sufficient). An example of open system would be boiling water in an open pan on the stove, matter and energy are transferred. A closed system would be putting a lid on the pan, no matter transfer just energy.
by Sheridan Slaterbeck 1J
Sun Feb 03, 2019 11:20 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Closed Systems
Replies: 6
Views: 69

Re: Closed Systems

In a closed system the matter remains constant but energy can be transferred between surroundings and the system.
An isolated system neither energy or matter can be transferred.
by Sheridan Slaterbeck 1J
Sun Feb 03, 2019 11:16 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Midterm [ENDORSED]
Replies: 48
Views: 1011

Re: Midterm [ENDORSED]

I would say the homework problems, and the extra study guides some of the UA's post like I know Lyndon usually does one.
by Sheridan Slaterbeck 1J
Sun Jan 27, 2019 6:12 pm
Forum: Phase Changes & Related Calculations
Topic: Steam
Replies: 7
Views: 86

Re: Steam

Also think about how fast steam phase changes back to liquid on your skin, because the process happens so fast it releases a very large amount of heat energy in a very short amount of time. If it was released over a longer period of time, it wouldn't be nearly as harmful.
by Sheridan Slaterbeck 1J
Sun Jan 27, 2019 6:08 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Catalysts in Kc
Replies: 6
Views: 101

Re: Catalysts in Kc

Catalysts change the speed at which the reaction occurs, not the components.
by Sheridan Slaterbeck 1J
Sun Jan 27, 2019 6:07 pm
Forum: Administrative Questions and Class Announcements
Topic: Lecture Slides
Replies: 5
Views: 99

Re: Lecture Slides

Lavelle doesn't post them, if you missed one day you could just read the textbook and be fine though.
by Sheridan Slaterbeck 1J
Sun Jan 27, 2019 6:05 pm
Forum: Phase Changes & Related Calculations
Topic: Delta H
Replies: 11
Views: 169

Re: Delta H

+H = endothermic the reactions needs heat
-H = exothermic the reaction gives off heat
by Sheridan Slaterbeck 1J
Sun Jan 27, 2019 6:02 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5%
Replies: 10
Views: 157

Re: 5%

5% rule is a way you can test if you assume x is so small of a number it is negligible in finding x. for example if Kc= x^2 / (.55-x) you could try the assumption and calculate for x like this Kc=x^2 /(.55). Once you get a value you can test if it is less than 5% of the initial concentration given. ...
by Sheridan Slaterbeck 1J
Thu Jan 24, 2019 10:20 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 179
Views: 6947

Re: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)

How did the NH3 become 11.3* 10^-7 On worksheet 1 4d
by Sheridan Slaterbeck 1J
Mon Jan 14, 2019 12:01 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: K and Q [ENDORSED]
Replies: 7
Views: 106

Re: K and Q [ENDORSED]

Even though K and Q have the same formula P/R it is the numbers that you plug in that are different. Only once the reaction reaches equilibrium can you plug in for K. But Q is at any point during the reaction. K is only one number, whereas Q can be many different numbers.
by Sheridan Slaterbeck 1J
Sun Jan 13, 2019 11:48 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW PROBELM 1 PART D
Replies: 4
Views: 75

Re: HW PROBELM 1 PART D

The reasoning is Le Chatelier's Principle= chem reactions adjust so as to minimize the effect of changes.
by Sheridan Slaterbeck 1J
Sun Jan 13, 2019 11:45 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

It is basically the concept that chemical reactions by nature adjust so as to minimize the effect of changes. When equilibria is changed, like if more reactant was added more product is produced until original P/R ratio is attained. Or if more product is added, more reactant will form until the the ...
by Sheridan Slaterbeck 1J
Sun Jan 13, 2019 11:35 pm
Forum: Student Social/Study Group
Topic: New to Lavelle
Replies: 32
Views: 617

Re: New to Lavelle

Some of the UAs will post practice Tests before the midterm and final that are really helpful for studying, last quarter Lyndon posted them.
by Sheridan Slaterbeck 1J
Sun Dec 02, 2018 10:31 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs angular?
Replies: 15
Views: 218

Re: Bent vs angular?

Dr. Lavelle said they are the same thing.
by Sheridan Slaterbeck 1J
Sun Dec 02, 2018 10:30 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: How to draw dipoles
Replies: 3
Views: 81

Re: How to draw dipoles

The dipole should point to the more electronegative element in a bond of two elements. Example between O and F, the dipole would point to F. If two different dipoles point opposite directions they cancel each other out, if all cancel out the molecule is non-polar. If they have a net dipole moment th...
by Sheridan Slaterbeck 1J
Sun Dec 02, 2018 10:22 pm
Forum: Hybridization
Topic: hybridization
Replies: 13
Views: 295

Re: hybridization

I think you have to draw out the Lewis structure for sure, then count electron densities and find subsequent and matching spd number
s=1
sp=2
sp2 =3
sp3 =4
sp3d =5 etc
by Sheridan Slaterbeck 1J
Sun Dec 02, 2018 10:18 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Planar
Replies: 12
Views: 195

Re: Square Planar

The two lone pairs balance each other out on top and bottom, and the four bonds make a plus shape on one plane, each exactly 90 degrees apart.
by Sheridan Slaterbeck 1J
Sun Nov 25, 2018 10:34 pm
Forum: Lewis Structures
Topic: Expanded Octet
Replies: 8
Views: 153

Re: Expanded Octet

Row 2 elements usually never have expanded octet.
by Sheridan Slaterbeck 1J
Sun Nov 25, 2018 10:33 pm
Forum: Hybridization
Topic: Test 3
Replies: 7
Views: 137

Re: Test 3

My TA said the test should be similar in number to the other tests, so about 8 questions
by Sheridan Slaterbeck 1J
Sun Nov 25, 2018 10:31 pm
Forum: Properties of Light
Topic: Speed of light
Replies: 13
Views: 234

Re: Speed of light

My TA said to use the number given on the equation sheet otherwise rounding may affect your final answer and they can take points off for that.
by Sheridan Slaterbeck 1J
Sun Nov 18, 2018 11:00 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles for H2O
Replies: 8
Views: 204

Re: Bond Angles for H2O

The lone pairs push the bonding pairs H-O on both sides to increase the angle between lone pair and the hydrogen oxygen bond, but this decreases the angle between the two bonding pairs to 104.5 instead of 109.5
by Sheridan Slaterbeck 1J
Sun Nov 18, 2018 10:54 pm
Forum: Hybridization
Topic: Bond Angles
Replies: 12
Views: 209

Re: Bond Angles

If you know the VSEPR model , you should be able to remember the bond angle associated with it like 120, or 109.5, or 90 degrees. Then figure out how the lone pairs push on the bonding pairs and affect the angles ( I find this is easiest by drawing it).
by Sheridan Slaterbeck 1J
Sun Nov 18, 2018 10:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: lone pairs
Replies: 11
Views: 153

Re: lone pairs

Lone pairs have a large affect on the shape of the molecule, lone pairs push nearby bonding pairs away creating a greater angle than if it were a bonding pair to bonding pair. Making the other angles decrease.
by Sheridan Slaterbeck 1J
Sun Nov 11, 2018 10:19 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 12
Views: 436

Re: Formal Charge

I think you should always show your calculations for formal charge, each TA grades differently but my TA said the more work you show the greater chance you will earn more points.
by Sheridan Slaterbeck 1J
Sun Nov 11, 2018 10:14 pm
Forum: Octet Exceptions
Topic: learning octet excptions
Replies: 4
Views: 88

Re: learning octet excptions

My TA said you don't have to memorize these just know that it could be possible in periods 3 and on, but not in period 1 or 2.
by Sheridan Slaterbeck 1J
Sun Nov 11, 2018 10:07 pm
Forum: Resonance Structures
Topic: Drawing resonance
Replies: 17
Views: 510

Re: Drawing resonance

One of the TA's said we are not able to tell yet if a structure has resonance, we will learn that later. We will be told when to draw resonance structures as of now.
by Sheridan Slaterbeck 1J
Sun Nov 04, 2018 11:58 pm
Forum: Sigma & Pi Bonds
Topic: Midterm1
Replies: 10
Views: 290

Re: Midterm1

I don't think so. If it was not mentioned in class it won't be on the test.
by Sheridan Slaterbeck 1J
Sun Nov 04, 2018 11:57 pm
Forum: Lewis Structures
Topic: Expanded Octet Rule
Replies: 4
Views: 78

Re: Expanded Octet Rule

Someone in a review session today said it could be more than 10, don't think we have to know the specifics.
by Sheridan Slaterbeck 1J
Sun Nov 04, 2018 11:56 pm
Forum: Trends in The Periodic Table
Topic: Periodic Trends: Diagonal Relationships
Replies: 3
Views: 210

Re: Periodic Trends: Diagonal Relationships

In a review session today they said they would not ask us this without giving us values for which one has a higher ionization.
by Sheridan Slaterbeck 1J
Sun Oct 28, 2018 10:51 pm
Forum: Ionic & Covalent Bonds
Topic: Difference Between Ionic and Covalent Bonds
Replies: 4
Views: 62

Re: Difference Between Ionic and Covalent Bonds

On the periodic table metals form cations, they have low ionization energy. Which means they have larger size, and electrons are farther from nucleus, so they are easily removed from s and p orbitals and do not require a lot of energy for the process. The p-block nonmetals form anions, meaning they ...
by Sheridan Slaterbeck 1J
Sun Oct 28, 2018 10:36 pm
Forum: Ionic & Covalent Bonds
Topic: Cation/Anion Size
Replies: 3
Views: 61

Re: Cation/Anion Size

Essentially the number of protons and electrons equal each other in a neutral atom. And after a neutral atom loses a certain amount of electrons, this new cation now has less electrons in comparison to protons. Now that the positive charge protons outnumber the e-, the e- are pulled in tighter to th...
by Sheridan Slaterbeck 1J
Sun Oct 28, 2018 10:29 pm
Forum: Lewis Structures
Topic: Lewis Structure for Compounds
Replies: 6
Views: 121

Re: Lewis Structure for Compounds

Cations lose their outermost electrons causing it to change from a neutral atom to a +positively charged atom. Two cations would repel each other since both would be +positive.
by Sheridan Slaterbeck 1J
Wed Oct 24, 2018 8:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Grading question
Replies: 11
Views: 648

Re: Grading question

Chem_Mod wrote:No. All it means it that 250/500 is needed to pass with the class (likely a C- because that is the minimum grade needed to pass the class).

What amount of points would be a B- or A-? Is there a set scale now or only provided by the end of the quarter?
by Sheridan Slaterbeck 1J
Sun Oct 21, 2018 11:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Class Grading
Replies: 9
Views: 336

Re: Class Grading

Does anyone know the range of an A in the class, a B, and C. In terms of points or percentage. I am a little confused because on the syllabus it says a passing grade C- is a 50%... ??
by Sheridan Slaterbeck 1J
Sun Oct 21, 2018 11:52 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron Spin States?
Replies: 4
Views: 77

Re: Electron Spin States?

I think all we need to know is that no two electrons in the same atom have the same four quantum #s. And that spin states can either be+1/2 or -1/2 .
by Sheridan Slaterbeck 1J
Sun Oct 21, 2018 11:49 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: h with a line through it?
Replies: 8
Views: 154

Re: h with a line through it?

H bar is just a short hand notation, that is used just to simplify what is written. ( Hbar= h/2 pi) (H bar/2 = h/4 pi)
by Sheridan Slaterbeck 1J
Sun Oct 14, 2018 11:31 pm
Forum: Administrative Questions and Class Announcements
Topic: Writing in Pen
Replies: 13
Views: 296

Re: Writing in Pen

My TA said that if you write in pencil on your test he has to write over everything you wrote in pen, so you can't change your answers later. But do whatever makes you feel less stressed and more focused. I use to hate writing in pen but forcing your self to use it more and more will help. Usually a...
by Sheridan Slaterbeck 1J
Sun Oct 14, 2018 11:26 pm
Forum: Student Social/Study Group
Topic: Class Grades
Replies: 4
Views: 148

Re: Class Grades

I personally like using benegg.net as my grade calculator. Easy to understand and helpful in giving you a close estimate of your final grade. I agree with others in that writing down your grades on little assignments as you go is the best way to keep track. Sometimes TAs do make mistakes.
by Sheridan Slaterbeck 1J
Sun Oct 14, 2018 11:21 pm
Forum: Student Social/Study Group
Topic: Note Taking
Replies: 32
Views: 1528

Re: Note Taking

I also find handwritten notes to be the best way for me to take notes. I am a very visual learner, so I often use colors too. I find that if I highlight "too much" information I tend to loose focus of what formulas and topics are the most important. Recently I have been actively working on...
by Sheridan Slaterbeck 1J
Sun Oct 07, 2018 11:56 pm
Forum: Student Social/Study Group
Topic: HW Schedule?
Replies: 7
Views: 274

Re: HW Schedule?

My Ta said the same thing, homework for outline 2 (quantum) and test will be due on your discussion day. They said the test will be 40 min.
by Sheridan Slaterbeck 1J
Sun Oct 07, 2018 11:54 pm
Forum: SI Units, Unit Conversions
Topic: How does grading for discussion posts work?
Replies: 73
Views: 2221

Re: How does grading for discussion posts work?

Also a question about the cutoff, is each week's post due that Sunday by midnight..?
by Sheridan Slaterbeck 1J
Sun Oct 07, 2018 11:50 pm
Forum: Significant Figures
Topic: Formula sheet?
Replies: 5
Views: 182

Formula sheet?

Are we going to be told what will be on the formula sheet for Test one next week in discussion? Do we even get a formula sheet?

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