Search found 62 matches

by Lorie Seuylemezian-2K
Fri Mar 16, 2018 7:26 am
Forum: Method of Initial Rates (To Determine n and k)
Topic: Test 3 question 5
Replies: 3
Views: 233

Re: Test 3 question 5

Given the instantaneous rate of the reaction. 2.7 x 10^2 andninitial mass of 1.8g confined to a 750ml vessel, what is the rate constant of this reaction. From the previous questions we have they the rate equation is rate=k[h2o][o2]^2
by Lorie Seuylemezian-2K
Thu Mar 15, 2018 4:08 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Test 3 question 5
Replies: 3
Views: 233

Test 3 question 5

Hey could anyone help me work through question 5 on test 3 i got the n, and the standard e correct but not the last question where you have to find the rate constant
by Lorie Seuylemezian-2K
Wed Mar 14, 2018 1:40 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow steps and intermediates
Replies: 2
Views: 79

Re: Slow steps and intermediates

I agree with the above answer the slow step is the one with the matching rate law
by Lorie Seuylemezian-2K
Wed Mar 14, 2018 1:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Minimum for a B-?
Replies: 3
Views: 240

Re: Minimum for a B-?

I believe that everything between a 50-79% is a C and then regular percentages above that for B and C
by Lorie Seuylemezian-2K
Tue Mar 06, 2018 9:32 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetics Test
Replies: 2
Views: 143

Re: Kinetics Test

My TA said the same thing about hw problemss I believe it’s material until last Friday’s lecture
by Lorie Seuylemezian-2K
Tue Mar 06, 2018 9:23 am
Forum: General Rate Laws
Topic: Average vs. Unique Average Reaction Rate
Replies: 1
Views: 76

Re: Average vs. Unique Average Reaction Rate

I think the best explanation for this is the endorses chem_mod post that you can access in the announcements page!
by Lorie Seuylemezian-2K
Tue Mar 06, 2018 9:10 am
Forum: First Order Reactions
Topic: 15.25
Replies: 4
Views: 208

Re: 15.25

Got it this makes sense now!
by Lorie Seuylemezian-2K
Sun Mar 04, 2018 5:25 pm
Forum: First Order Reactions
Topic: 15.25
Replies: 4
Views: 208

15.25

Can someone explain where we get the reaction A= e^-kt * ao
by Lorie Seuylemezian-2K
Wed Feb 28, 2018 1:28 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Hw 15.1 [ENDORSED]
Replies: 7
Views: 280

Re: Hw 15.1 [ENDORSED]

Yes I also agree! You use the coefficients and divide or multiply accordingly
by Lorie Seuylemezian-2K
Wed Feb 28, 2018 1:25 pm
Forum: First Order Reactions
Topic: Deriving these Equations
Replies: 7
Views: 238

Re: Deriving these Equations

I believe it needs to explicitly show [A]o or else we are unsure what order concentration is given
by Lorie Seuylemezian-2K
Wed Feb 28, 2018 1:13 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Test 3
Replies: 2
Views: 104

Test 3

Does anyone know how much of kinetics (ch 15) will be on the test week 9?
by Lorie Seuylemezian-2K
Tue Feb 20, 2018 8:56 pm
Forum: Balancing Redox Reactions
Topic: 3A Determining reduction vs oxidation
Replies: 4
Views: 128

3A Determining reduction vs oxidation

I am having trouble identifying the reducing and oxidizing agent in equations such as 3a in the homework?
by Lorie Seuylemezian-2K
Tue Feb 20, 2018 8:54 pm
Forum: Balancing Redox Reactions
Topic: 14.3 (a)
Replies: 3
Views: 174

Re: 14.3 (a)

No there is a -2 charge on both sides of the equation.
reactants: 2- from s2o3
products: 4- from so4, 10+ from h, 8e-
by Lorie Seuylemezian-2K
Tue Feb 20, 2018 8:50 pm
Forum: Balancing Redox Reactions
Topic: 14.1 D
Replies: 3
Views: 150

Re: 14.1 D

This is because we multiply the half reactions with a coefficient in order to cancel out the electrons on both sides.
by Lorie Seuylemezian-2K
Thu Feb 15, 2018 3:14 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: What does E stand for?
Replies: 3
Views: 200

Re: What does E stand for?

E is cell potential which will not be covered on the midterm.
by Lorie Seuylemezian-2K
Thu Feb 15, 2018 3:13 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 5
Views: 227

Re: Hess's Law

Yes you can! You don't call it hesss law but the same theory is used to make similar calculations
by Lorie Seuylemezian-2K
Thu Feb 15, 2018 3:11 pm
Forum: Calculating Work of Expansion
Topic: Calculating work for winter 2013 midterm 4.B.
Replies: 4
Views: 185

Re: Calculating work for winter 2013 midterm 4.B.

What equation we use is based on if the equation is reversible or not. If it is reversible we use the equation with R in it and if it is irreversible we use the equation with w=-pextdeltaV
by Lorie Seuylemezian-2K
Wed Feb 14, 2018 12:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm format
Replies: 2
Views: 178

Re: Midterm format

Yes, all of dr. lavelles tests follow the same format, except the midterm is longer than the tests and the final is even longer than that.
by Lorie Seuylemezian-2K
Mon Feb 12, 2018 9:56 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Test #7
Replies: 7
Views: 259

Re: Test #7

Can someone please show me their work with the numbers for this no matter what I do i keep getting the wrong answer?
by Lorie Seuylemezian-2K
Wed Feb 07, 2018 1:25 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 11.19
Replies: 1
Views: 100

Re: 11.19

I believe we the question usually specifies if it is not calcite. (like they do with diamond when carbon is in the question).
by Lorie Seuylemezian-2K
Wed Feb 07, 2018 1:21 pm
Forum: Phase Changes & Related Calculations
Topic: Endothermic/exothermic
Replies: 4
Views: 299

Endothermic/exothermic

On the first quiz there was a question regarding heat exchange and release I had trouble understanding if you use endothermic/exothermic to answer these or just common knowledge such as the sun heats up water during evaporation therefore there is heat exchange.
by Lorie Seuylemezian-2K
Wed Feb 07, 2018 1:19 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: quiz question #7
Replies: 1
Views: 127

quiz question #7

Can someone help me work through #7 on quiz 1 the one with five steps of enthalpies we must calculate.
by Lorie Seuylemezian-2K
Wed Jan 31, 2018 2:57 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Class Example
Replies: 6
Views: 167

Re: Class Example

Dr. Lavelle continued to explain that the final answer is anything higher than 333k will result in a spontaneous reaction in the forward direction.
by Lorie Seuylemezian-2K
Wed Jan 31, 2018 2:52 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Can a system exchange matter but not energy?
Replies: 4
Views: 157

Re: Can a system exchange matter but not energy?

I also think this is not possible because if a system exchanges matter the energy will also exchange. Therefore if a system is exchanging matter I think it always classified as a open system.
by Lorie Seuylemezian-2K
Wed Jan 31, 2018 2:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm topics
Replies: 1
Views: 126

Midterm topics

Does anyone know what the last chapter on the midterm will be?
by Lorie Seuylemezian-2K
Tue Jan 23, 2018 3:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework Turn In for Week 3
Replies: 2
Views: 135

Re: Homework Turn In for Week 3

My TA asked us to move on to chapter 9 he said if you can't do all chapter 9 do half chapter 8 and half chapter 9
by Lorie Seuylemezian-2K
Tue Jan 23, 2018 3:48 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 3 Test Topic is endorsed
Replies: 37
Views: 1806

Re: Week 3 Test Topic is endorsed

After going through the homework I noticed numbers 3-13,25-31, and 47-49 all have to do with calculating work or internal energy. I would suggest studying all the other homework problems specifically for this upcoming test. Can anyone else confirm that these problems aren't going to be tested on? I...
by Lorie Seuylemezian-2K
Tue Jan 23, 2018 3:33 pm
Forum: Phase Changes & Related Calculations
Topic: HW 8.1
Replies: 2
Views: 112

HW 8.1

Can someone explain to me how coffee in a thermos is an isolated system? Doesn't heat still escape?
by Lorie Seuylemezian-2K
Thu Jan 18, 2018 11:00 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Specific Heat Capacity
Replies: 5
Views: 196

Re: Specific Heat Capacity

I agree with the responses above that this is just a convention to allow us to do the calculations for solutions.
by Lorie Seuylemezian-2K
Thu Jan 18, 2018 10:58 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 5
Views: 190

Re: Bond Enthalpies

This makes sense now, thank you all for the responses! I was having trouble grasping the concept earlier.
by Lorie Seuylemezian-2K
Thu Jan 18, 2018 10:57 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.29 heat capacity
Replies: 3
Views: 122

8.29 heat capacity

Can someone explain to me why heat capacity increases as molecular complexity increases?
by Lorie Seuylemezian-2K
Wed Jan 10, 2018 2:50 pm
Forum: Phase Changes & Related Calculations
Topic: Heat and Phase Transition
Replies: 3
Views: 154

Heat and Phase Transition

Can someone explain how a sample's temp remains constant during phase transitions?
by Lorie Seuylemezian-2K
Wed Jan 10, 2018 2:49 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Bond Enthalpies
Replies: 5
Views: 190

Bond Enthalpies

Can someone help me figure out for the bond enthalpies method why the reactants have positive enthalpies and the products negative?
by Lorie Seuylemezian-2K
Wed Jan 10, 2018 2:43 pm
Forum: Phase Changes & Related Calculations
Topic: Endo and Exothermic Ways to Remember
Replies: 28
Views: 2458

Re: Endo and Exothermic Ways to Remember

I use the prefixes, Ex->exiting heat, en-> entering heat or needing heat.
by Lorie Seuylemezian-2K
Fri Dec 08, 2017 10:42 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le chateliers principle
Replies: 3
Views: 259

Le chateliers principle

Can someone please explain this principle to me and how we are supposed to apply it?
by Lorie Seuylemezian-2K
Fri Dec 08, 2017 2:50 pm
Forum: Naming
Topic: Naming
Replies: 4
Views: 214

Re: Naming

Could someone help me name and draw the Lewis structure for the test problem [HgF2(OH2)2]+
by Lorie Seuylemezian-2K
Mon Dec 04, 2017 11:12 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Using The Equilibrium Arrow
Replies: 5
Views: 515

Re: Using The Equilibrium Arrow

Yes I agree with the post above! Only use the equilibrium arrow when you are working with weak acids and bases.
by Lorie Seuylemezian-2K
Mon Dec 04, 2017 11:11 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE table question
Replies: 5
Views: 2359

Re: ICE table question

Always remember to keep it consistent! If one reactant is decreasing by X then all of them should be decreasing and visa versa!
by Lorie Seuylemezian-2K
Mon Dec 04, 2017 11:07 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Question 11.7
Replies: 4
Views: 243

Re: Question 11.7

Thank you so much! I just wasn't understanding why we originally count out of 17 but now I get it!
by Lorie Seuylemezian-2K
Thu Nov 30, 2017 12:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Question 11.7
Replies: 4
Views: 243

Re: Question 11.7

Can someone help me out with part C of 11.7, I don’t really understand why the answer book is out of 17?
by Lorie Seuylemezian-2K
Tue Nov 28, 2017 6:30 pm
Forum: Sigma & Pi Bonds
Topic: Sigma and pi
Replies: 12
Views: 599

Re: Sigma and pi

Is the single sigma bond always the "center" bond?
by Lorie Seuylemezian-2K
Tue Nov 28, 2017 5:53 pm
Forum: Naming
Topic: Naming polydentates
Replies: 1
Views: 105

Re: Naming polydentates

I believe you name it based on the exact type that the ligand is acting as in the specific polydentate.
by Lorie Seuylemezian-2K
Mon Nov 20, 2017 10:21 am
Forum: Electronegativity
Topic: Electroegativity
Replies: 9
Views: 459

Re: Electroegativity

In my opinion knowing the trend is the easiest way to remember the electronegativity of different elements. An easy trick for that is just learning the atomic radius trend and knowing that everything else is the opposite! The only exception there is for the last group of elements because their valen...
by Lorie Seuylemezian-2K
Mon Nov 20, 2017 10:04 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Are moleculary geometry and shape different? [ENDORSED]
Replies: 3
Views: 233

Re: Are moleculary geometry and shape different? [ENDORSED]

I believe they are different things. Molecular shape is the 3D structure of a molecule which includes the bond angles and the orientation of the different atoms. On the other hand molecular geometry is the name of the shape for example trigonal planar or tetrahedral.
by Lorie Seuylemezian-2K
Mon Nov 13, 2017 10:47 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Homework week 7
Replies: 1
Views: 118

Homework week 7

Does anyone know if the homework from week 7 is from chapter 4 or chapter 17?
by Lorie Seuylemezian-2K
Mon Nov 13, 2017 10:44 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Memorization
Replies: 5
Views: 268

Re: Memorization

Personally, I️ think memorizing what type of shape a certain number atom molecule is and the angles associated with that is the quickest way to learn! But once you know it for a single 3 atom molecule you know it for all 3 atom molecules!
by Lorie Seuylemezian-2K
Mon Nov 13, 2017 10:43 am
Forum: Formal Charge and Oxidation Numbers
Topic: A tip for calculating formal charge [ENDORSED]
Replies: 2
Views: 3031

Re: A tip for calculating formal charge [ENDORSED]

I️ agree with this tip! It helps to prevent errors in calculation which can ruin your Lewis structure
by Lorie Seuylemezian-2K
Mon Nov 06, 2017 11:10 am
Forum: Administrative Questions and Class Announcements
Topic: Homework for this week [ENDORSED]
Replies: 2
Views: 185

Re: Homework for this week [ENDORSED]

The homework for this week is ch 4! However I’m not sure how the discussions on Friday turn in the homework!
by Lorie Seuylemezian-2K
Mon Nov 06, 2017 11:07 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: unpaired electrons [ENDORSED]
Replies: 3
Views: 210

Re: unpaired electrons [ENDORSED]

Determining whether or not electrons are paired can be done using an Aufbau diagram if every electron has a pair for example 2 arrows on every line than all electrons are paired! An easy trick is if the number of electrons in each sub shell is at the maximum then all electrons are paired.
by Lorie Seuylemezian-2K
Mon Nov 06, 2017 11:05 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Energy of subshells
Replies: 2
Views: 157

Re: Energy of subshells

5s has a lower energy until there are 2 electrons in that orbital. Once there are 2 electrics 4d has a lower energy!
by Lorie Seuylemezian-2K
Mon Oct 30, 2017 8:26 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: 2.63
Replies: 2
Views: 152

2.63

Can someone help me work through chapter 2 section 63?
by Lorie Seuylemezian-2K
Mon Oct 30, 2017 8:22 pm
Forum: Octet Exceptions
Topic: lewis structures
Replies: 2
Views: 234

Re: lewis structures

Can anyone explain how we determine the bonding when it comes to exceptions to the octet rule ad drawing lewis structures.
by Lorie Seuylemezian-2K
Mon Oct 23, 2017 11:31 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron orbital filling order [ENDORSED]
Replies: 1
Views: 144

Re: Electron orbital filling order [ENDORSED]

There is no scientific reason why we fill the px orbital first. Theoretically, it could fill any on of them however we start with px for simplicity.
by Lorie Seuylemezian-2K
Mon Oct 23, 2017 11:28 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Chromium and Copper Electron Configuration Exceptions [ENDORSED]
Replies: 5
Views: 463

Re: Chromium and Copper Electron Configuration Exceptions [ENDORSED]

Is there a reason for this exception? (the difference in stability)
by Lorie Seuylemezian-2K
Mon Oct 16, 2017 11:33 am
Forum: Empirical & Molecular Formulas
Topic: Test 1 Compound X [ENDORSED]
Replies: 5
Views: 364

Re: Test 1 Compound X [ENDORSED]

This helps so much! Thank you, Is there any combustion where we know the oxygen because in the homework there were sceniors where we did not approach the problem this way.
by Lorie Seuylemezian-2K
Mon Oct 16, 2017 11:23 am
Forum: DeBroglie Equation
Topic: De Broglie Wavelength
Replies: 14
Views: 932

Re: De Broglie Wavelength

What is the smallest wavelength that can be detected?
by Lorie Seuylemezian-2K
Fri Oct 13, 2017 8:58 am
Forum: Photoelectric Effect
Topic: Problem 1.7 HW
Replies: 4
Views: 268

Re: Problem 1.7 HW

I also solved the problem and got 150 pm, I think the back of the book is a typo as the solutions manual agrees with our answer.
by Lorie Seuylemezian-2K
Fri Oct 13, 2017 8:57 am
Forum: Empirical & Molecular Formulas
Topic: Test 1 Compound X [ENDORSED]
Replies: 5
Views: 364

Test 1 Compound X [ENDORSED]

Can someone help me work through the compound X question on Test 1. It was the second to last question on the test?
by Lorie Seuylemezian-2K
Fri Oct 06, 2017 5:31 pm
Forum: Molarity, Solutions, Dilutions
Topic: E9 [ENDORSED]
Replies: 5
Views: 884

Re: E9 [ENDORSED]

Can someone explain step by step how to do step B
by Lorie Seuylemezian-2K
Thu Oct 05, 2017 7:53 pm
Forum: SI Units, Unit Conversions
Topic: Sig Figs [ENDORSED]
Replies: 16
Views: 1832

Re: Sig Figs [ENDORSED]

Hello!
I just wanted to ask if the 0 after the number 0.0450 counts as a significant figure? Is this 5 or 4 sig figs?

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