Search found 32 matches

by AvaM1c
Fri Mar 11, 2016 2:51 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 2012 Final #4B Deriving Rate Law
Replies: 2
Views: 272

Re: 2012 Final #4B Deriving Rate Law

sorry i meant to write the second part of part A
by AvaM1c
Fri Mar 11, 2016 2:50 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 2012 Final #4A Deriving rate law
Replies: 1
Views: 222

2012 Final #4A Deriving rate law

For the second step in Part A, why do you not use the slow step to derive the rate law for the mechanism?
by AvaM1c
Thu Mar 10, 2016 11:26 pm
Forum: *Nucleophilic Substitution
Topic: 2013 5C
Replies: 1
Views: 575

2013 5C

Why do you not use the double bond on (Z)-2-iodobut-2-enol as a nucleophile and use the NH as a nucleophile instead? Basically why does the negative atom get a higher priority of being a nucleophile?

also for the second part when it asks what type of reaction this is, how do you know it is SN2?
by AvaM1c
Thu Mar 10, 2016 11:07 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 2012 #3 Drawing Galvanic Cell
Replies: 3
Views: 349

Re: 2012 #3 Drawing Galvanic Cell

Chem_Mod wrote:How's this?

galvanic_diagram.png

perfect thank you!
by AvaM1c
Thu Mar 10, 2016 11:06 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Winter Final 2013 4B
Replies: 1
Views: 259

Winter Final 2013 4B

Image

for 4B I understand how to derive Q=1/[O2] (products/reactants) but I do not understand how the rest of the work is solved. Can someone explain it please?
by AvaM1c
Thu Mar 10, 2016 3:19 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 2012 Final #4B Deriving Rate Law
Replies: 2
Views: 272

2012 Final #4B Deriving Rate Law

For part B, why do you not use the slow step to derive the rate law for the mechanism?
by AvaM1c
Thu Mar 10, 2016 2:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 2012 #3 Drawing Galvanic Cell
Replies: 3
Views: 349

2012 #3 Drawing Galvanic Cell

Can someone please upload a picture of how the galvanic cell in part A is supposed to look like? I'm a visual person and I'm having trouble trying to draw the galvanic cell based on the answer provided
by AvaM1c
Wed Mar 02, 2016 3:30 pm
Forum: *Alkanes
Topic: is HI a nucleophile or electrophile
Replies: 1
Views: 1110

Re: is HI a nucleophile or electrophile

HI (same with HBr) is an electrophile because it doesn't have a full octet
by AvaM1c
Wed Mar 02, 2016 3:28 pm
Forum: *Alkanes
Topic: prioritizing naming
Replies: 2
Views: 244

Re: prioritizing naming

chloro because if its the same distance, you number alphabetically
by AvaM1c
Wed Mar 02, 2016 3:27 pm
Forum: *Alkanes
Topic: Nucleophile vs electrophile
Replies: 2
Views: 245

Re: Nucleophile vs electrophile

Nucleophile: has double bonds, triple bonds, lone pairs, or negative charge

Electrophile: doesn't have a full octet, positive charge
by AvaM1c
Sun Feb 28, 2016 6:43 pm
Forum: *Alkenes
Topic: Homework 1.12C naming
Replies: 2
Views: 368

Homework 1.12C naming

Hi, for naming CH3CHC(CH3)C(CH3)3 I named it 2-2-3-trimethyl-3-pentene but the book answer has it as 3-4-4-trimethyl-2-pentene. Can someone please explain why my answer is wrong?
by AvaM1c
Wed Feb 24, 2016 10:35 pm
Forum: *Nucleophilic Substitution
Topic: 4.34 nucleophile
Replies: 1
Views: 273

4.34 nucleophile

For question 4.34, why is it that both the H and the O act as the nucleophile in one step together, instead of only the O which carries the lone pairs

and also how do you know it's only 1 transition step
by AvaM1c
Wed Feb 24, 2016 9:16 pm
Forum: *Electrophilic Addition
Topic: reaction profiling
Replies: 1
Views: 240

Re: reaction profiling

Since step 1 requires breaking 2 bonds while step 2 involves formation of 1 bond, a higher activation energy is needed for the first step and it is therefore slower


(basically breaking bonds requires more energy than forming bonds)
by AvaM1c
Wed Feb 24, 2016 9:12 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Homework 4.30 n
Replies: 1
Views: 227

Re: Homework 4.30 n

on page 154 of the "Introduction to Organic Chemistry" textbook, it explains how reactions with activation energies below 80 kJ/mol can occur at room temperature but those with larger activation energies need added energy to occur
by AvaM1c
Wed Feb 24, 2016 9:07 pm
Forum: *Electrophiles
Topic: Thermody. and Kineticsof Organic Rxns Textbook Review
Replies: 1
Views: 258

Re: Thermody. and Kineticsof Organic Rxns Textbook Review

The assigned reading/ problems are actually not from the textbook, they are from the orange "Introduction to Organic Chemistry" book that can be bought from the course reader store in Westwood; the vender sold the course reader and the orange book together to most people so you might have ...
by AvaM1c
Wed Feb 24, 2016 8:59 pm
Forum: *Electrophiles
Topic: Electrophilic Elements
Replies: 1
Views: 278

Re: Electrophilic Elements

Atoms that do not have a full octet (such as F since it has 7 valence electrons instead of 8) are considered to have an "open valence" and therefore could be considered electrophiles because they are technically "electron deficient"
by AvaM1c
Mon Feb 15, 2016 9:40 am
Forum: First Order Reactions
Topic: finding t 15.37
Replies: 2
Views: 420

finding t 15.37

for 15.37 b, when finding the equation for t I got

but the solutions manual derives that it is

The answer comes out the same, but I was wondering if there was something I am doing wrong?
by AvaM1c
Sat Feb 13, 2016 2:46 pm
Forum: General Rate Laws
Topic: Unique rate
Replies: 1
Views: 202

Unique rate

When finding the unique rate of a reaction, for example 15.3 C, why do we not put a negative in front of the answer since it is being consumed?
by AvaM1c
Wed Feb 10, 2016 8:41 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Midterm 2015 Q6 Nernst
Replies: 1
Views: 194

Midterm 2015 Q6 Nernst

For Q6 when it asks you to solve for K could we have used the Nernst equation? Because I solved it and got 5.5 E27 and the answer is given as 1.1 E28
by AvaM1c
Tue Feb 09, 2016 9:49 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Winter 2015 Midterm Q1 q
Replies: 1
Views: 301

Winter 2015 Midterm Q1 q

for Q1A how do you know that it's not qsys=-qsurr because isn't there a heat transfer happening between the kettle and the water
by AvaM1c
Tue Feb 09, 2016 9:42 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Winter 2015 Midterm Q1 heat
Replies: 1
Views: 310

Winter 2015 Midterm Q1 heat

When changing the temperature of the water from 22 degrees Celsius to 100 degrees Celsius why do you not need to account for the heat change of the water going from 22 degrees celsius to the standard temperature of water (25 degrees Celsius) before calculating it going to 100 degrees celsius (boilin...
by AvaM1c
Mon Feb 08, 2016 10:29 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Winter 2011 Midterm Nernst Equation ln
Replies: 2
Views: 387

Winter 2011 Midterm Nernst Equation ln

Hi for question 7 / 8 D I try using the ln equation instead of the log equation (since either one can be used) and i get a totally off answer. can someone please explain to me what I'm doing wrong? these are my steps: Step 1: .100V= 0.33V-\frac{.0025678233}{2} lnQ Step 2: \frac{.097}{-.00128}= lnQ S...
by AvaM1c
Sat Feb 06, 2016 8:02 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Question 14.41 finding Q
Replies: 1
Views: 236

Question 14.41 finding Q

Question 14.41 a states: Calculate E for each of the following concentration cells: (a) Cu(s) \left | Cu^{2+} (aq, 0.0010 mol/L/) \left | \right |Cu^{2+}(aq, 0.010 mol/L) \right | Cu(s) I know that we have to use Nernst Equation but how do we know which concentrati...
by AvaM1c
Thu Feb 04, 2016 10:03 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: physical diagram
Replies: 1
Views: 221

physical diagram

In a physical diagram of redox rxns, do you need a salt bridge if you have a porous disk?
by AvaM1c
Wed Feb 03, 2016 9:04 pm
Forum: Balancing Redox Reactions
Topic: Basic Half Reactions
Replies: 1
Views: 264

Re: Basic Half Reactions

These are the steps for balancing a redox equation in a BASIC solution: STEP 1) Identify which element is being reduced (gains electrons) and which element is oxidized (loses electrons) and form 2 half reactions. STEP 2) Balance all the elements EXCEPT for O and H. STEP 3) Balance the Oxygen by addi...
by AvaM1c
Tue Feb 02, 2016 5:14 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs Free Energy values
Replies: 1
Views: 145

Gibbs Free Energy values

Can someone please explain when we could use the Gibbs free energy of formation values given directly to us in Appendix 2A or when we have to derive it using enthalpy and entropy values
by AvaM1c
Tue Feb 02, 2016 4:48 pm
Forum: Balancing Redox Reactions
Topic: Add H+ or OH-
Replies: 5
Views: 1741

Add H+ or OH-

How do you know when you have to add H+ and when you have to add OH- when balancing a redox reaction?
by AvaM1c
Mon Feb 01, 2016 8:58 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: calculating cell potential
Replies: 1
Views: 268

Re: calculating cell potential

Yes exactly! K means the concentration of the products and reactants are at equilibrium (equal) and Q is the concentrations at any other value
by AvaM1c
Fri Jan 22, 2016 9:49 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: 1st law thermodynamics
Replies: 1
Views: 258

Re: 1st law thermodynamics

entropy of gas > entropy of liquid > entropy of solid entropy is a measure of disorder and since in a gas, the molecules have more space to move around freely and randomly there is more disorder, and it follows with the particles in a solid having the least amount of space to move around because the...
by AvaM1c
Wed Jan 13, 2016 5:43 pm
Forum: Phase Changes & Related Calculations
Topic: Hess's Law
Replies: 1
Views: 213

Hess's Law

For question 8.57 : Determine the reaction enthalpy for the hydrogenation of ethyne to ethane, C2H2(g)  2 H2(g) S C2H6(g), from the following data: Hc(C2H2, g)  1300. kJ·mol1, Hc(C2H6, g)  1560. kJ·mol1, Hc(H2, g)  286 kJ·mol1. I don't understand why in the solutions book it is showi...
by AvaM1c
Fri Jan 08, 2016 6:25 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hess's Law
Replies: 1
Views: 202

Re: Hess's Law

Standard state means it is at 1 atm which I think means at room temperature (for example the standard state of water is liquid and the standard state of Hydrogen is gas)

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