## Search found 72 matches

Sat Mar 16, 2019 1:22 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.69 6th Edition
Replies: 3
Views: 153

### Re: 15.69 6th Edition

Nevermind I understand now, thanks!
Sat Mar 16, 2019 12:47 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.69 6th Edition
Replies: 3
Views: 153

### Re: 15.69 6th Edition

Sorry I'm still a little confused. How did you get rid of k1?
Fri Mar 15, 2019 9:23 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.69 6th Edition
Replies: 3
Views: 153

### 15.69 6th Edition

A reaction rate increases by a factor of 1000. in the presence of a catalyst at 25 'C. The activation energy of the original pathway is 98 kJ!mol!1. What is the activation energy of the new pathway, all other factors being equal? In practice, the new pathway also has a different pre-exponential fact...
Fri Mar 15, 2019 9:16 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.61 equation
Replies: 3
Views: 418

### Re: 15.61 equation

Madelyn Cearlock wrote:is the second equation necessary to use? would the first equation produce the same answer?

Yes, they produce the same answer. These two equations are the same thing, just in different formats.
Fri Mar 15, 2019 4:51 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.63 (6th addition)
Replies: 3
Views: 133

### Re: 15.63 (6th edition)

I'm getting stuck on this question too. I was looking at the solution and I was wondering where 0.59 came from. This is the solution: ln(k'/k) = (38 kJ/mol)/(0.08314 kJ/molK) ln(\frac{k'}{k}) = \frac{38 kJ/mol}{0.08314 kJ/molK}(\frac{1}{298 K}-\frac{1}{310 K}) - 0.59 \frac{k'...
Fri Mar 15, 2019 4:40 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: activation energy
Replies: 3
Views: 120

### Re: activation energy

How do we determine which one is K1 and which one is K2?
Fri Mar 15, 2019 4:39 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.63 (6th addition)
Replies: 3
Views: 133

### Re: 15.63 (6th edition)

I'm getting stuck on this question too. I was looking at the solution and I was wondering where 0.59 came from.
Mon Feb 25, 2019 11:05 pm
Forum: Balancing Redox Reactions
Topic: Water in Redox Reactions [ENDORSED]
Replies: 3
Views: 134

### Re: Water in Redox Reactions[ENDORSED]

Don't we add water to basic solutions too?
Mon Feb 25, 2019 11:04 pm
Forum: Balancing Redox Reactions
Topic: Adding H+, OH- and H20
Replies: 4
Views: 320

### Re: Adding H+, OH- and H20

When do we know when to add H2O on both sides?
Mon Feb 25, 2019 8:34 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 179
Views: 12652

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

When we balance the equations on worksheet 7, how do we know which side of the reaction to add H2O to?
Mon Feb 25, 2019 5:56 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 179
Views: 12652

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

For the worksheet 7 (electrochem) question 2, I don't get why the E value would cause C to be false. Can someone explain this to me please?
Mon Feb 25, 2019 10:41 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: 6th edition 9.65
Replies: 2
Views: 297

### Re: 6th edition 9.65

Just to make sure, the most stable form is the substance that has a delta G formation that is less positive right?
Mon Feb 25, 2019 1:01 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 6th edition 9.57
Replies: 1
Views: 76

### Re: 6th edition 9.57

For question 9.57 in the 6th edition, I don't get how to calculate \Delta H^{\circ}_{r} . In the solution manual, it says \Delta H^{\circ}_{r} = 2 \Delta H^{\circ}_{f} (H2O, aq) - 2 \Delta H^{\circ}_{f} (H2O2,l). Where did H2O,aq come from? Also, what is the general formula for \Delta H^{\circ}_{r}...
Mon Feb 25, 2019 12:37 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: 6th edition 9.65
Replies: 2
Views: 297

### 6th edition 9.65

Which of the following compounds become less stable with respect to the elements as the temperature is raised: (a) PCl5(g); (b) HCN(g); (c) NO(g); (d) SO2(g)? How do we know which substances to use when writing the balanced equation? For instance, in (b) why do we use C(s), graphite instead of C(g) ...
Sun Feb 24, 2019 11:27 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 6th edition 9.57
Replies: 1
Views: 76

### 6th edition 9.57

For question 9.57 in the 6th edition, I don't get how to calculate \Delta H^{\circ}_{r} . In the solution manual, it says \Delta H^{\circ}_{r} = 2 \Delta H^{\circ}_{f} (H2O, aq) - 2 \Delta H^{\circ}_{f} (H2O2,l). Where did H2O,aq come from? Also, what is the general formula for \Delta H^{\circ}_{r} ?
Wed Feb 13, 2019 3:36 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 179
Views: 12652

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

Anjali_Kumar1F wrote:Is there answer where it shows the work for these worksheets.

No, she only posts the answer key online, but during her workshop, she goes over how to do the problems!
Tue Feb 12, 2019 10:24 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 179
Views: 12652

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

For worksheet 4, is the answer for 6a wrong? I did (3/2)(31.9 mol)(8.314 J/Kmol)(311.15 K) = 124 kJ. When I didn't convert the temperature from C to K I got 15.1 kJ which is the answer given in the key. We don’t have to convert it to kelvin as it is change in temperature (38-0) Don't we need to con...
Tue Feb 12, 2019 10:22 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 179
Views: 12652

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

Celine Hoh 2L wrote:
Karyn Nguyen 1K wrote:For worksheet 4, is the answer for 6a wrong? I did (3/2)(31.9 mol)(8.314 J/Kmol)(311.15 K) = 124 kJ. When I didn't convert the temperature from C to K I got 15.1 kJ which is the answer given in the key.

We don’t have to convert it to kelvin as it is change in temperature (38-0)
Tue Feb 12, 2019 9:53 pm
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 179
Views: 12652

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

For worksheet 4, is the answer for 6a wrong? I did (3/2)(31.9 mol)(8.314 J/Kmol)(311.15 K) = 124 kJ. When I didn't convert the temperature from C to K I got 15.1 kJ which is the answer given in the key.
Tue Feb 12, 2019 4:02 pm
Forum: Calculating Work of Expansion
Topic: 6th edition self test 8.1A
Replies: 1
Views: 80

### 6th edition self test 8.1A

Water expands when it freezes. How much work does 100. g of water do when it freezes at 0.0 C and pushes back the metal wall of a pipe that exerts an opposing pressure of 1070 atm? The densities of water and ice at 0.0C are 1.00 gcm3 and 0.92 gcm3, respectively. I'm a little confused on how to...
Tue Feb 12, 2019 3:35 pm
Forum: Calculating Work of Expansion
Topic: constant external pressure
Replies: 2
Views: 127

### constant external pressure

How do we know if the external pressure is constant in order to use $w=P_{ex}\Delta v$?
Mon Feb 11, 2019 11:45 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Question 8.19 (Sixth Edition)
Replies: 3
Views: 189

### Re: Question 8.19 (Sixth Edition)

Where did you get 0.38 J/gC?
Mon Feb 11, 2019 6:00 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Units for Entropy
Replies: 3
Views: 743

### Re: Units for Entropy

Do we have to convert C to K or can we just leave it as C?
Mon Feb 11, 2019 5:15 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: bond dissociation energy
Replies: 1
Views: 129

### bond dissociation energy

Calculate \Delta H^{\circ}_{rxn} using bond dissociation energy of: H_{2} + Cl_{2}\rightarrow 2 HCl H-H = 432 kJ/mol Cl-Cl = 239 kJ/mol H-Cl = 427 kJ/mol Why do we divide the equation by 2 and use \frac{1}{2}H_{2} + \frac{1}{2}Cl_{2} \rightarrow 1HCl to get the right answer which is -91.5 kJ/mol?
Tue Jan 22, 2019 11:05 am
Forum: Administrative Questions and Class Announcements
Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sun 7-9PM (Karen)
Replies: 179
Views: 12652

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

For 4b on worksheet 2, I keep getting 4.73x10^(-8) for the concentration of CO3. Can someone explain what I'm doing wrong? I got 3.99x10^(-5) for the concentration of H2CO3.
Mon Jan 21, 2019 10:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6th edition 12.69 Ka
Replies: 3
Views: 161

### Re: 6th edition 12.69 Ka

Also, are we expected to be know how to write the chemical reaction?
Mon Jan 21, 2019 10:37 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 6th edition 12.69 Ka
Replies: 3
Views: 161

### Re: 6th edition 12.69 Ka

I have the same question too! I looked at Tables 12.1 and 12.2 but I didn't see the K value for it.
Sun Jan 20, 2019 7:21 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 11.3 6th edition
Replies: 3
Views: 114

### 11.3 6th edition

For (b) in this question, I was wondering why we don't balance the equation first and then give K?

Write the equilibrium expression K for each of the following reactions:
(a) 2C2H4(g) + O2(g) + 4HCl(g) = 2C2H4Cl2(g) + 2H2O(g)
(b) 4NH3(g) + 6NO(g) = 7N2(g) + 6H2O(g)
Sun Jan 20, 2019 5:21 pm
Forum: Lewis Acids & Bases
Topic: Identifying Acids and Bases
Replies: 5
Views: 425

### Re: Identifying Acids and Bases

Cienna Henry 1J wrote:
Karyn Nguyen 1K wrote:What acids and bases (strong and weak) would be helpful to memorize?

Memorize all strong acids and bases (there aren't that many). Then you will know that all other acids/bases are weak.

Thanks! If anyone is wondering, in the 6th edition of the textbook, Table J.1 lists strong acids and bases.
Sun Jan 20, 2019 5:08 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chateliers Principle
Replies: 4
Views: 158

### Re: Le Chateliers Principle

$N_{2} + 3H_{2} \rightleftharpoons 2NH_{3}$

What happens if we increase $N_{2}$? Increase $NH_{3}$? Decrease $H_{2}$?

This was explained during lecture, but I'm still a little confused. Can someone explain this to me again?
Sun Jan 20, 2019 4:56 pm
Forum: Student Social/Study Group
Topic: test 1
Replies: 10
Views: 624

### Re: test 1

Will we be tested on concepts (like multiple choice or short answers) or will it just be math problems?
Sun Jan 20, 2019 4:54 pm
Forum: Student Social/Study Group
Topic: test 1
Replies: 10
Views: 624

### Re: test 1

Test 1 covers Equilibrium and Acid & Base Equilibria so it'll be outlines 1 and 2
Sun Jan 20, 2019 4:51 pm
Forum: Lewis Acids & Bases
Topic: Identifying Acids and Bases
Replies: 5
Views: 425

### Re: Identifying Acids and Bases

What acids and bases (strong and weak) would be helpful to memorize?
Sun Jan 20, 2019 4:47 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 3
Views: 108

### Re: Le Chatelier's Principle

Also, since Le Chatelier's principle is only used at equilibrium what do we use if it's not at equilibrium?
Sun Jan 20, 2019 4:45 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Le Chatelier's Principle
Replies: 3
Views: 108

### Le Chatelier's Principle

Can someone explain why changing the concentration doesn't change K but changing the temperature does?
Thu Jan 10, 2019 7:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework 11.39 Edition 6
Replies: 4
Views: 203

### Re: Homework 11.39 Edition 6

Why do we multiply K instead of adding it?
Thu Jan 10, 2019 7:23 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: K vs Q [ENDORSED]
Replies: 7
Views: 300

### K vs Q[ENDORSED]

What's the difference between the formula for the equilibrium constant K and the formula for the reaction quotient Q?
Wed Jan 09, 2019 4:58 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q
Replies: 6
Views: 147

### Re: Q

Can someone explain what exactly Q is? I know that it is the reactant quotient but I don't get why Q and K wouldn't always equal each other if they have the same formula [P]/[R]?
Wed Jan 09, 2019 4:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Calculating the Equilibrium Composition in ATP Hydrolysis
Replies: 4
Views: 109

### Re: Calculating the Equilibrium Composition in ATP Hydrolysis

How would we solve the problem if we didn't assume ADP and P are 0?
Tue Jan 08, 2019 3:33 pm
Forum: Administrative Questions and Class Announcements
Topic: TA Office Hours & Discussion Sections Lecture 4 [ENDORSED]
Replies: 1
Views: 151

### TA Office Hours & Discussion Sections Lecture 4[ENDORSED]

When will the "TA Office Hours & Discussion Sections Lecture 4" page be updated? As of right now, it's displaying information for lecture 2.
Wed Jun 13, 2018 10:28 pm
Forum: Ionic & Covalent Bonds
Topic: ionic character
Replies: 11
Views: 1345

### Re: ionic character

I'm just a little confused because this doesn't apply when comparing MgCl2 and CaCl2 because CaCl2 has a greater ionic character.
Wed Jun 13, 2018 9:52 pm
Forum: Ionic & Covalent Bonds
Topic: ionic character
Replies: 11
Views: 1345

### Re: ionic character

I thought the greater difference in electronegativity corresponds with a greater ionic character? NaBr has a lower difference in electronegativity than NaI doesn't it?
Wed Jun 13, 2018 6:23 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands
Replies: 2
Views: 245

### Re: Ligands

Which ligands and their charges do we have to memorize for the final?
Wed Jun 13, 2018 1:11 am
Forum: Naming
Topic: Oxidation Numbers and how to get them
Replies: 4
Views: 414

### Re: Oxidation Numbers and how to get them

How do we find out the charge for the ligand?
Tue Jun 12, 2018 10:47 pm
Forum: Lewis Acids & Bases
Topic: Determine Lewis Acid
Replies: 13
Views: 820

### Re: Determine Lewis Acid

I'm in the same situation. How are we supposed to know which one is an acid or base by looking at it?
Mon Jun 11, 2018 9:45 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: bond that coordinates
Replies: 1
Views: 107

### bond that coordinates

How do we know which bond coordinates to the metal? I know the atoms with lone pairs have the potential to coordinate, but which ones actually do?
Mon Jun 11, 2018 9:42 pm
Forum: Lewis Acids & Bases
Topic: Order of acidity or basicity
Replies: 2
Views: 258

### Order of acidity or basicity

When ranking compounds in order of acidity or basicity, do we just look at the bond length and the corresponding strength of the bond? Also, do we convert the compound to its conjugate acid for bases in order to rank them?
Mon Jun 11, 2018 9:38 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Optical isomers [ENDORSED]
Replies: 1
Views: 136

### Optical isomers[ENDORSED]

What exactly are optical isomers and how do we draw them?
Mon Jun 11, 2018 8:32 pm
Forum: Ionic & Covalent Bonds
Topic: ionic character
Replies: 11
Views: 1345

### ionic character

why does NaBr have a greater ionic character than NaI?
Wed May 30, 2018 5:02 pm
Forum: Student Social/Study Group
Topic: Finals week
Replies: 1
Views: 162

### Finals week

Are there going to be set ups and workshops during finals week?
Wed May 30, 2018 4:59 pm
Forum: Resonance Structures
Topic: ranking
Replies: 11
Views: 748

### Re: ranking

vivianndo_1L wrote:If the two resonance structures have the same formal charge, would they be considered equal in rank?

Resonance structures are supposed to have the same formal charge, but they can differ in rank.
Fri May 25, 2018 1:10 am
Forum: Lewis Structures
Topic: Lewis acid and base
Replies: 1
Views: 104

### Lewis acid and base

Is lewis acids and bases on test 3?
Thu May 24, 2018 11:56 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Character?
Replies: 3
Views: 323

### Re: Covalent Character?

Just to clarify, something has greater covalent character if its electronegativity is lower and has a bigger atomic radius?
Thu May 24, 2018 10:55 pm
Forum: Resonance Structures
Topic: ranking
Replies: 11
Views: 748

### ranking

How do we rank resonance structures in order of importance to the overall structure?
Thu May 24, 2018 8:59 pm
Forum: General Science Questions
Topic: Chapter 6
Replies: 3
Views: 265

### Re: Chapter 6

Oh okay thank you!
Thu May 24, 2018 8:57 pm
Forum: Lewis Structures
Topic: Test 3 [ENDORSED]
Replies: 4
Views: 484

### Re: Test 3[ENDORSED]

I'm a little confused on what else we're supposed to know about chapter 3 other than being able to draw lewis structures?
Thu May 24, 2018 1:12 am
Forum: General Science Questions
Topic: Chapter 6
Replies: 3
Views: 265

### Chapter 6

Did we start chapter 6 on Monday 5/21/18?
Sun May 13, 2018 7:58 pm
Forum: Administrative Questions and Class Announcements
Topic: Returned midterms
Replies: 1
Views: 195

### Returned midterms

Will midterms be handed out during discussion if we can't get it after class on Wednesday?
Sun May 06, 2018 8:56 pm
Forum: Molarity, Solutions, Dilutions
Topic: Test 1, Q1
Replies: 2
Views: 280

### Re: Test 1, Q1

I'm a little confused on how we're supposed to know KCl --> K+ + Cl- . Also for CaCl2 --> Ca2+ + 2Cl-
Sun May 06, 2018 8:47 pm
Forum: General Science Questions
Topic: Solutions for tests
Replies: 3
Views: 354

### Solutions for tests

Are the solutions for the tests going to be posted or would we have to go to office hours?
Sun May 06, 2018 8:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 1 Lab Worksheet
Replies: 2
Views: 302

### Re: Week 1 Lab Worksheet

Update: she never responded
Sun May 06, 2018 8:43 pm
Forum: *Shrodinger Equation
Topic: Shrodinger Equation
Replies: 7
Views: 464

### Re: Shrodinger Equation

If we don't have to apply this equation in the class, would we be expected to explain the experiment and how they derived the equation on the midterm?
Sat Apr 21, 2018 1:21 pm
Forum: General Science Questions
Topic: Workshops/step ups [ENDORSED]
Replies: 2
Views: 377

### Workshops/step ups[ENDORSED]

Which workshop or step up is the best one to go to for a test review?
Sat Apr 21, 2018 1:18 pm
Forum: General Science Questions
Topic: Test #2 [ENDORSED]
Replies: 6
Views: 609

### Re: Test #2[ENDORSED]

Are there going to be that many questions on test 2? Because the last test was already a time crunch...
Sat Apr 21, 2018 1:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Switching discussion [ENDORSED]
Replies: 6
Views: 360

### Re: Switching discussion[ENDORSED]

Thanks Phil for the offer, but it's okay I worked it out!
Thu Apr 12, 2018 12:14 pm
Forum: Administrative Questions and Class Announcements
Topic: Switching discussion [ENDORSED]
Replies: 6
Views: 360

### Re: Switching discussion[ENDORSED]

1-1:50 on Fridays!
Wed Apr 11, 2018 3:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 1 Lab Worksheet
Replies: 2
Views: 302

### Re: Week 1 Lab Worksheet

I have the same question and emailed my TA about this a day ago. When she replies, I'll post it here, but if anyone else knows that would be helpful!
Wed Apr 11, 2018 3:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework for Week 2
Replies: 2
Views: 141

### Re: Homework for Week 2

I like to look at the syllabus for the homework since it's all compiled together which makes it easier to keep track of. For week 2, I'm pretty sure we do problems under "Review of Chemical & Physical Principles" and "The Quantum World."
Mon Apr 09, 2018 11:56 am
Forum: General Science Questions
Topic: Naming compunds
Replies: 3
Views: 432

### Re: Naming compunds

Here on this website :)
Sun Apr 08, 2018 8:11 pm
Forum: General Science Questions
Topic: Naming compunds
Replies: 3
Views: 432

### Re: Naming compunds

Nevermind, I found the answer to this question under the section empirical and molecular formulas.
Sun Apr 08, 2018 7:56 pm
Forum: General Science Questions
Topic: Naming compunds
Replies: 3
Views: 432

### Naming compunds

Some of the homework problems ask us to write the name of the compound in the question. Which ones should we memorize or are we expected to know how to identify any compound?
Fri Apr 06, 2018 5:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Switching discussion [ENDORSED]
Replies: 6
Views: 360

### Switching discussion[ENDORSED]

Hey is anyone in dis 1L willing to switch with me into dis 1K. I would greatly appreciate it!

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