Search found 68 matches
- Mon Mar 13, 2017 2:16 pm
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Green textbook 3.5-8
- Replies: 1
- Views: 558
Re: Green textbook 3.5-8
It depends on the atomic masses of the halogen. The heavier one gets priority.
- Mon Mar 13, 2017 2:16 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: A in the Arrhenius equation
- Replies: 2
- Views: 721
Re: A in the Arrhenius equation
A is the pre exponential factor. Usually it's the same in throughout a type of reaction. You could be asked to find it if you are given all the other values.
- Mon Mar 13, 2017 2:15 pm
- Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
- Topic: When to Use Z and E?
- Replies: 4
- Views: 929
Re: When to Use Z and E?
You use them when you notice the trends in the way they are ordered in terms of priority.
- Wed Mar 08, 2017 5:17 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Torsional Strain
- Replies: 2
- Views: 655
Torsional Strain
I'm a little confused as to what torsional strain is. Can anyone explain it?
- Mon Mar 06, 2017 9:27 pm
- Forum: General Science Questions
- Topic: Types of energy profiles
- Replies: 5
- Views: 1354
Re: Types of energy profiles
for the Gibbs free energy diagrams, do we look at delta G of activation for the second step from the intermediates to the transition state or in terms of the reactants to the transition state.
- Mon Mar 06, 2017 6:53 pm
- Forum: *Cycloalkenes
- Topic: Tert-Butyl vs Isobutyl
- Replies: 1
- Views: 731
Re: Tert-Butyl vs Isobutyl
iso is used for the general shape of (CH3)2CH, tert is when you have a T shape made up of carbon atoms.
- Mon Mar 06, 2017 6:52 pm
- Forum: General Science Questions
- Topic: Types of energy profiles
- Replies: 5
- Views: 1354
Types of energy profiles
How many types of energy profiles are there? I know there's an energy profile in terms of Gibbs free energy and one in terms of potential energy...are there any others we need to be aware of? What are the differences between the Gibbs free energy and the potential energy ones?
- Mon Mar 06, 2017 6:51 pm
- Forum: *Nucleophiles
- Topic: Determining nucleophile vs. Electrophile
- Replies: 1
- Views: 1706
Re: Determining nucleophile vs. Electrophile
The overall characteristic depends on the central atom and since C is in this case an electrophile because it is slightly positive, the molecule is therefore electrophilic.
- Mon Mar 06, 2017 6:48 pm
- Forum: *Electrophiles
- Topic: Halogens
- Replies: 9
- Views: 2442
Re: Halogens
Halogens are electron rich which is why they are nucleophiles.
- Mon Mar 06, 2017 6:46 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: quiz 2 #11
- Replies: 1
- Views: 539
Re: quiz 2 #11
Did you use the ln(k2/k1)=-Ea/R(1/T2-1/T1) formula? Cause when you do that with the known values you get 5611j/mol as your activation energy. Then you use that value with the same equation, replacing one of your K values and its corresponding T values for the 700K and solving for K which gives you t...
- Mon Mar 06, 2017 12:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Naming
- Replies: 1
- Views: 457
Naming
Can an "iso" group be at the end of a carbon chain or does it always have to be in the middle?
- Mon Feb 27, 2017 6:57 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz number 3
- Replies: 5
- Views: 1235
Quiz number 3
Will quiz number 3 cover the kinetics stuff that we reviewed last week or will it be strictly organic chemistry?
- Mon Feb 20, 2017 4:46 pm
- Forum: First Order Reactions
- Topic: Slope of k
- Replies: 3
- Views: 978
Re: Slope of k
Second order reactions are 1/A vs time therefore the slope increases as concentration decreases which is why the slop for that is positive.
- Mon Feb 20, 2017 4:44 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: WHat is the unit of k
- Replies: 4
- Views: 1097
Re: WHat is the unit of k
The units of the rate constant vary depending on the reaction order.
- Mon Feb 20, 2017 4:43 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Quiz 2
- Replies: 1
- Views: 565
Re: Quiz 2
Yes, Dr. Lavelle posted the answers under the "Quiz 2 Winter 2017" post.
- Mon Feb 20, 2017 4:42 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Rate law of rxn mechanisms
- Replies: 1
- Views: 515
Rate law of rxn mechanisms
When do we use the steady step approach vs the pre equilibrium approach?
- Wed Feb 15, 2017 1:06 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Book problem 14.55
- Replies: 2
- Views: 555
Re: Book problem 14.55
Why did they use water for the other half reaction?
- Mon Feb 13, 2017 6:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Units?
- Replies: 1
- Views: 517
Re: Units?
I don't think you get marked off for writing J or KJ unless the question specifies that you give it to one form or the other. Also it doesn't affect the sig figs, those primarily depend on the values given in the question.
- Mon Feb 13, 2017 6:53 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Midterm 2017
- Replies: 2
- Views: 557
Re: Midterm 2017
I don't think so.
- Mon Feb 13, 2017 6:52 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Standard Molar Entropy
- Replies: 1
- Views: 1160
Re: Standard Molar Entropy
The heavier the molecule the greater the entropy. The less symmetry a molecule has the higher the entropy. So if you were to compare CH4 and CH2Cl2...CH2Cl2 would have a higher entropy because there is more disorder associated with the lack of symmetry.
- Mon Feb 13, 2017 6:50 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Practice midterm 2016 #8A
- Replies: 1
- Views: 549
Re: Practice midterm 2016 #8A
You look at the cell potentials. Whichever one is larger is the cathode and is therefore being reduced. The smaller, more negative value is the cell potential for the anode and is therefore oxidized.
- Mon Feb 06, 2017 3:42 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cells
- Replies: 1
- Views: 442
Re: Galvanic Cells
I don't think we learned solubility product...
- Wed Feb 01, 2017 5:21 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Units of H, S, G, U, q, and w
- Replies: 1
- Views: 484
Re: Units of H, S, G, U, q, and w
enthalpy kj/mol, entropy j/K*mol, free energy kj, heat kj, and work kj
- Sun Jan 29, 2017 9:34 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible vs Irreversible Expansion
- Replies: 1
- Views: 469
Re: Reversible vs Irreversible Expansion
Reversible means that the reaction can easily go back to its initial form completely. It's like 100% of the reverse reaction went back to create its initial reactants which is why there is no change in internal energy.
- Sun Jan 29, 2017 9:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Entropy
- Replies: 2
- Views: 601
Entropy
Will 1.0g of CH4 (g) have the same entropy has 2.0g of CH4 (g)? Or will the 2.0g of CH4 have greater entropy because entropy is an extensive property and therefore the increase in mass will result in greater disorder?
- Sun Jan 29, 2017 1:46 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Quiz Prep #3
- Replies: 1
- Views: 428
Re: Quiz Prep #3
because the reaction is reversible and isothermal at variable pressure you use the 1=-nRTln(V2/V1) formula
- Sun Jan 29, 2017 1:40 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: When to use which q= equation?
- Replies: 1
- Views: 1920
Re: When to use which q= equation?
You use the one with mass when you are given or are trying to find the Specific Heat Capacity. The one with just CdeltaT is used when you are just trying to find or are given the Heat Capacity. And the Cp is the heat capacity at constant pressure.
- Tue Jan 24, 2017 10:01 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Molar Heat Capacity
- Replies: 2
- Views: 595
Re: Molar Heat Capacity
Basically when you have constant volume of 1 atom of an ideal gas the molar heat capacity is 3/2R (R is rydberg's constant) Whereas if you have constant pressure of 1 atom of a gas the molar heat capacity is 5/2R. Now if you have linear molecules or non linear molecules these values differ. There's ...
- Tue Jan 17, 2017 8:48 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: kJ vs. kJ per mole?
- Replies: 3
- Views: 980
Re: kJ vs. kJ per mole?
You use KJ per mole when you're finding the standard enthalpy of formation because it is the formation of 1 mol of a compound from its constituent elements. However, if you're just finding the enthalpy of a reaction you just use KJ. Also, my TA said that bond enthalpies can be written in KJ or KJ pe...
- Fri Jan 13, 2017 4:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem Final [ENDORSED]
- Replies: 6
- Views: 1776
Re: Chem Final [ENDORSED]
I think you can pick them during week 3 of this quarter from 4006 Young Hall
- Mon Jan 09, 2017 6:29 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Organic Chem Textbook
- Replies: 1
- Views: 595
Re: Organic Chem Textbook
I think we start organic chemistry towards the end of the quarter so probably by then.
- Fri Dec 02, 2016 6:26 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Ionic Radius
- Replies: 1
- Views: 458
Ionic Radius
Which would have the largest ionic radius? Cl- Br- I-
- Wed Nov 30, 2016 3:54 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemical Equilibria
- Replies: 1
- Views: 520
Chemical Equilibria
On page 457 question 11.35 there's a formula used to convert K to Kc, are we expected to know that for the final? Did we go over this in class?
- Mon Nov 21, 2016 1:53 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp and Kc
- Replies: 4
- Views: 960
Re: Kp and Kc
Also for Kc you use these brackets: [ ] but for Kp you use normal brackets ( )
- Mon Nov 14, 2016 9:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Gases
- Replies: 1
- Views: 360
Re: Gases
Use P when dealing with pressures and brackets when dealing with concentrations.
- Mon Nov 14, 2016 9:15 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How do you find the number of attachment possible?
- Replies: 3
- Views: 809
Re: How do you find the number of attachment possible?
ethylenediammine it's a bidentate because it has 2 nitrogens. Each nitrogen is bound to only 2 hydrogens which means they have a lone pair of electrons that can bond to the transition metal.
- Mon Nov 14, 2016 9:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Having multiple possible concentrations [ENDORSED]
- Replies: 1
- Views: 468
Re: Having multiple possible concentrations [ENDORSED]
If both are positive you can figure out which one is correct by subtracting it from the initial concentration. If it gives you a negative initial concentration then you can disregard it cause the value is too large.
- Mon Nov 14, 2016 9:12 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands [ENDORSED]
- Replies: 2
- Views: 620
Re: Ligands [ENDORSED]
Most of the time you can tell from the charge. Like F- Cl- OH- etc are all monodentates. SO42- is bidentate etc. Ethylenediammine is a bidentate cause there are 2 nitrogens each with one lone pair. So looking at the number of nitrogens can be a good indication of the number of bonds it can form.
- Mon Nov 14, 2016 5:05 pm
- Forum: *Molecular Orbital Theory Applied To Transition Metals
- Topic: 4.67
- Replies: 2
- Views: 1147
Re: 4.67
You would calculate the bond orders for each one and so the one would the highest bond order would have the highest ionization energy because the bond is stronger. Then you would compare if the electrons are higher or lower in energy. Electrons in the higher energy orbitals mean that they are easier...
- Mon Nov 14, 2016 2:48 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Naming Coordination Compounds [ENDORSED]
- Replies: 2
- Views: 1115
Naming Coordination Compounds [ENDORSED]
If there's an H2O outside the complex, do we refer to it as hydrate or aqua?
For example: K3[Fe(CN6)]3H2O
For example: K3[Fe(CN6)]3H2O
- Mon Nov 14, 2016 10:36 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination number and oxidation [ENDORSED]
- Replies: 1
- Views: 1272
Re: Coordination number and oxidation [ENDORSED]
The coordination number is the number of bonds formed. So from this you can deduce that the coordination number will be 6 because each NH3 will bind once and then there is a chlorine; this gives a total of 6. The oxidation number is solved by looking at the charges of each molecule. So the Cl2 charg...
Re: Ligands
Ligands are electron rich species that bind to transition metal cations by forming coordinate covalent bonds
- Mon Nov 14, 2016 10:32 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligand Names
- Replies: 3
- Views: 714
Re: Ligand Names
I don't think so.
- Mon Nov 14, 2016 10:32 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: M.O. Theory Conceptual Basis
- Replies: 2
- Views: 623
Re: M.O. Theory Conceptual Basis
We use the molecular orbital theory to give information about:
1. whether or not resonance structures exist (ex. if the bond order has a half in it (0.5, 2.5 etc) then the molecule has a resonance structure)
2. unpaired and paired electrons
3. bond energies
1. whether or not resonance structures exist (ex. if the bond order has a half in it (0.5, 2.5 etc) then the molecule has a resonance structure)
2. unpaired and paired electrons
3. bond energies
- Sun Nov 13, 2016 6:07 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Ligands
- Replies: 1
- Views: 562
Ligands
Is nitrosyl (NO) bidentate?
- Sun Nov 13, 2016 12:30 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Wrting the Chemical Formula for Coordination Compounds
- Replies: 3
- Views: 3021
Re: Wrting the Chemical Formula for Coordination Compounds
When writing out the chemical formula the order doesn't matter. However, when writing out the name then it's alphabetical.
- Sun Nov 13, 2016 12:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Prep for Quiz 3
- Replies: 1
- Views: 452
Re: Prep for Quiz 3
From the PLF sessions with the UAs they said that these questions won't be asked on the quiz since we haven't gone over them yet. Dr. Lavelle said only the first 4 pages of the equilibrium stuff in the course reader will be on the quiz.
- Sun Nov 13, 2016 12:29 pm
- Forum: Naming
- Topic: Naming Vanadium
- Replies: 1
- Views: 901
Re: Naming Vanadium
I think it's vanadate
- Sun Nov 13, 2016 12:28 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Polydentates
- Replies: 1
- Views: 420
Re: Polydentates
If it has lone pairs of electrons or a negative charge then it's most likely a polydentate and can bind to a metal in those regions.
- Wed Nov 09, 2016 3:53 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: K vs Kc
- Replies: 6
- Views: 9186
Re: K vs Kc
If they give you pressure then it's Kp if they give you concentration then it's Kc
- Wed Nov 09, 2016 3:52 pm
- Forum: Naming
- Topic: Right name for the complex ion
- Replies: 2
- Views: 755
Re: Right name for the complex ion
Using ferrate is the correct way but my TA said that we wouldn't need to use the latin names on quizzes/exams.
- Wed Nov 09, 2016 3:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Class on Wednesday November 23
- Replies: 2
- Views: 822
Re: Class on Wednesday November 23
I don't know if there will be class or not...but all the lectures are bruin cast.
- Mon Nov 07, 2016 2:29 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: The Difference Between Sigma and Sigma* Levels
- Replies: 1
- Views: 636
Re: The Difference Between Sigma and Sigma* Levels
They have more energy because they are not bonded and therefore are more reactive. The bonded ones are more stable and as a result have lower energy.
- Mon Oct 31, 2016 2:28 pm
- Forum: Hybridization
- Topic: Hybridization Order
- Replies: 4
- Views: 915
Re: Hybridization Order
Okay, thank you.
- Mon Oct 31, 2016 2:27 pm
- Forum: Resonance Structures
- Topic: Stable Lewis Structures
- Replies: 3
- Views: 915
Stable Lewis Structures
If we're asked a question about VSEPR theory but it says to draw a lewis structure, does it matter if we just draw any lewis structure of the compound? Or do we have to draw the most stable resonance structure?
- Mon Oct 31, 2016 1:46 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: D-block exceptions for midterm and f-block
- Replies: 4
- Views: 1185
Re: D-block exceptions for midterm and f-block
And I don't think you need to know f block orbitals.
- Mon Oct 31, 2016 1:46 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: D-block exceptions for midterm and f-block
- Replies: 4
- Views: 1185
Re: D-block exceptions for midterm and f-block
I think the only two we need to focus on are copper and chromium.
- Mon Oct 31, 2016 1:44 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Studying for the Midterm
- Replies: 2
- Views: 810
Re: Studying for the Midterm
Do practice questions from the course reader and the questions in the workbook as well.
- Mon Oct 31, 2016 1:43 pm
- Forum: Hybridization
- Topic: Hybridization Order
- Replies: 4
- Views: 915
Hybridization Order
When writing out hybridization does it matter if we put d before s and p or after s and p? In the course reader it's written as dsp^3 but in the textbook solutions it's written as sp^3d.
- Tue Oct 25, 2016 11:17 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Noble Gases and Electron Affinity
- Replies: 3
- Views: 875
Re: Noble Gases and Electron Affinity
If you look at electron affinity values, all noble gasses have an electron affinity of 0.
- Tue Oct 18, 2016 11:06 am
- Forum: Administrative Questions and Class Announcements
- Topic: The First Quiz
- Replies: 1
- Views: 409
Re: The First Quiz
Hey, I just had discussion today and we got our actual quizzes and workbooks back. It says the points on it.
- Wed Oct 12, 2016 10:24 pm
- Forum: Ionic & Covalent Bonds
- Topic: question 2.93
- Replies: 3
- Views: 827
Re: question 2.93
Yeah! Why would that not be the case?
- Mon Oct 10, 2016 6:05 pm
- Forum: Balancing Chemical Reactions
- Topic: Specifying state of molecule
- Replies: 1
- Views: 518
Re: Specifying state of molecule
We use it to specify which state each compound is in when running the experiment, but I don't think it impacts the molecular coefficients at all.
- Mon Oct 10, 2016 6:03 pm
- Forum: DeBroglie Equation
- Topic: De Broglie Equation Module Question
- Replies: 1
- Views: 627
Re: De Broglie Equation Module Question
It means that it doesn't have wavelike properties because it is too small to detect. Usually anything with a 10^-15 is the smallest wavelength that portrays these wavelike properties. Anything smaller cannot be detected consequently, you would say that it does not have wavelike properties.
- Wed Oct 05, 2016 1:10 pm
- Forum: Student Social/Study Group
- Topic: Sunset Village Study Group
- Replies: 17
- Views: 3601
Re: Sunset Village Study Group
I'm In C7 and I want to join! Did you guys make the study group yet?
- Wed Oct 05, 2016 1:07 pm
- Forum: Student Social/Study Group
- Topic: Rieber Hall 14A Study Group (Fall 2016)
- Replies: 49
- Views: 10234
Re: Rieber Hall 14A Study Group (Fall 2016)
It's not too late to join right?
- Sun Sep 25, 2016 5:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Homework Assignment?
- Replies: 7
- Views: 1266
Re: Homework Assignment?
Oh Alright! Thank you so much!
- Sun Sep 25, 2016 11:42 am
- Forum: Administrative Questions and Class Announcements
- Topic: Homework Assignment?
- Replies: 7
- Views: 1266
Re: Homework Assignment?
Do we have to do anything before tomorrow's lecture?