Search found 66 matches
- Mon Mar 11, 2019 11:51 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: 4D7 temperature
- Replies: 2
- Views: 310
Re: 4D7 temperature
I believe it's because it's a constant temperature.
- Mon Mar 11, 2019 11:43 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: 7th edition 6N.15
- Replies: 1
- Views: 303
Re: 7th edition 6N.15
6N.15
Calculate the potential of a cell constructed with two nickel electrodes. The electrolyte in one compartment is 1.0M Ni(NO3)2(aq). In the other compartment, NaOH has been added to a Ni(NO3)2 solution until the pH=11.0 at 298K. See Table 6I.1.
Calculate the potential of a cell constructed with two nickel electrodes. The electrolyte in one compartment is 1.0M Ni(NO3)2(aq). In the other compartment, NaOH has been added to a Ni(NO3)2 solution until the pH=11.0 at 298K. See Table 6I.1.
- Mon Mar 11, 2019 11:35 pm
- Forum: Student Social/Study Group
- Topic: Studying for the Final
- Replies: 25
- Views: 2568
Re: Studying for the Final
Yeah, I plan on doing the homework problems, the tests and midterm questions.
- Sun Mar 10, 2019 8:24 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Final Material
- Replies: 4
- Views: 451
Re: Final Material
I think questions that are also brought up on chemistry community.
- Wed Mar 06, 2019 7:49 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Disproportionation
- Replies: 1
- Views: 240
Re: Disproportionation
I believe disproportionation usually involves redox reaction; disproportionation reactions follow the form: 2A → A' + A"
- Wed Mar 06, 2019 7:45 pm
- Forum: Student Social/Study Group
- Topic: Final
- Replies: 24
- Views: 2016
Re: Final
I believe the sessions start Saturday but he has yet to give the times.
- Sun Mar 03, 2019 1:27 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Order of Cell Diagrams
- Replies: 13
- Views: 1484
Re: Order of Cell Diagrams
Solid|ion||ion|solid
- Sat Mar 02, 2019 12:22 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6M.3
- Replies: 2
- Views: 291
Re: 6M.3
Sorry! What I meant to say was why was C(gr) not included in Sn4+(aq)+2e- → Sn2+(aq) ?
- Wed Feb 27, 2019 6:43 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: platinum [ENDORSED]
- Replies: 6
- Views: 700
Re: platinum [ENDORSED]
You add Pt to the side that doesn't have a solid.
- Wed Feb 27, 2019 6:40 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Standard Cell Potential [ENDORSED]
- Replies: 2
- Views: 304
Re: Standard Cell Potential [ENDORSED]
The standard cell potential measures the driving force for a given redox reaction.
- Wed Feb 27, 2019 12:25 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6M.3
- Replies: 2
- Views: 291
6M.3
6M.3 Predict the standard potential of each of the following galvanic cells:
For part d, why is C(gr) not included for the anode?
(d) C(gr)|Sn4+ (aq),Sn2+ (aq)||Pb4+ (aq),Pb2+ (aq)| Pt(s)
For part d, why is C(gr) not included for the anode?
(d) C(gr)|Sn4+ (aq),Sn2+ (aq)||Pb4+ (aq),Pb2+ (aq)| Pt(s)
- Wed Feb 27, 2019 12:15 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram
- Replies: 3
- Views: 341
Re: Cell Diagram
Okay that makes sense. Thank you!
- Tue Feb 26, 2019 10:08 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram
- Replies: 3
- Views: 341
Cell Diagram
Why isn't H2O included in the cell diagram?
- Tue Feb 26, 2019 10:06 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Pt
- Replies: 2
- Views: 287
Re: Pt
I think you include it if you have gases and there's no solids.
- Mon Feb 25, 2019 2:15 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Voltage
- Replies: 2
- Views: 296
Re: Voltage
If I'm not mistaken, it's just a matter of preference.
- Mon Feb 25, 2019 2:13 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: DeltaG at Equilibrium
- Replies: 2
- Views: 273
Re: DeltaG at Equilibrium
If the free energy is zero, then the reaction is at equilibrium meaning that an no more work can be done.
- Sun Feb 24, 2019 11:52 pm
- Forum: Balancing Redox Reactions
- Topic: balancing redox reactions
- Replies: 2
- Views: 334
Re: balancing redox reactions
I second that, they can get confusing. Tips would be helpful!
- Sun Feb 24, 2019 11:51 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridges
- Replies: 3
- Views: 341
Re: Salt Bridges
Potassium chloride or sodium chloride are usually used.
- Sat Feb 23, 2019 8:13 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: How can a change in entropy be negative?
- Replies: 3
- Views: 430
Re: How can a change in entropy be negative?
If there is less disorder in a system, then entropy is negative.
- Sat Feb 23, 2019 8:10 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: What is the difference between entropy and free energy?
- Replies: 2
- Views: 2709
Re: What is the difference between entropy and free energy?
Gibbs free energy is energy available to do work and can be used to determine the spontaneity of a reaction. Entropy is a measure of the molecular disorder of a system.
- Sat Feb 23, 2019 3:50 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Test 3
- Replies: 14
- Views: 2244
Re: Test 3
I believe so since if ΔG=0 then it's at equilibrium.
- Sat Feb 23, 2019 3:44 pm
- Forum: Van't Hoff Equation
- Topic: Van't Hoff Equation
- Replies: 2
- Views: 563
Re: Van't Hoff Equation
I'm not too certain but i think you do.
- Fri Feb 22, 2019 10:17 pm
- Forum: Balancing Redox Reactions
- Topic: difference between oxidation and reduction
- Replies: 8
- Views: 892
Re: difference between oxidation and reduction
Remember that when an atom gains an electron, its reduction and when it loses electrons its oxidation.
- Fri Feb 22, 2019 8:39 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: delta G at equilibrium
- Replies: 1
- Views: 229
Re: delta G at equilibrium
Gibbs free energy measures how much potential a reaction has left. Hence if the free energy is zero, then the reaction is at equilibrium, and no more work can be done.
- Fri Feb 22, 2019 8:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 2
- Replies: 7
- Views: 810
Re: Test 2
Test 2 covers all topics on Gibbs free energy and electrochemistry up to but not including the Nernst equation!
- Thu Feb 21, 2019 10:17 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: electrodes
- Replies: 1
- Views: 248
Re: electrodes
https://chem.libretexts.org/Bookshelves ... _Chemistry)/Electrochemistry/Voltaic_Cells/The_Cell_Potential
This link is very helpful in explaining cell potential!
This link is very helpful in explaining cell potential!
- Thu Feb 21, 2019 10:15 pm
- Forum: Van't Hoff Equation
- Topic: Practice Problems
- Replies: 3
- Views: 512
Re: Practice Problems
I haven't seen any practice problems but do you know if we'll have to have graphical methods for Van't Hoff's equation?
- Wed Feb 20, 2019 9:52 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Midterm Question (#3.D)
- Replies: 2
- Views: 460
Re: Midterm Question (#3.D)
The solutions for the midterm are posted on the class website!
- Wed Feb 20, 2019 9:39 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: entropy
- Replies: 4
- Views: 593
Re: entropy
Enthalpy ('H') refers to the measure of total heat content in a thermodynamic system under constant pressure whereas enthalpy is calculated in terms of change. Keep in mind the the SI unit of enthalpy is joules (J).
- Wed Feb 20, 2019 9:17 pm
- Forum: Balancing Redox Reactions
- Topic: Week 7 Homework
- Replies: 15
- Views: 1139
Re: Week 7 Homework
I included gibbs free energy but also added some material on thermal dynamics.
- Wed Feb 20, 2019 9:10 pm
- Forum: Balancing Redox Reactions
- Topic: 6k.5 7th ed. Writing half reaction for basic solution
- Replies: 1
- Views: 231
Re: 6k.5 7th ed. Writing half reaction for basic solution
I'm actually struggling with grasping that subject too. I also thought it was oxidizing.
- Sun Feb 03, 2019 10:50 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Midterm
- Replies: 12
- Views: 2081
Re: Midterm
Yes, doing all of the homework questions help a lot because you'll realize what you need to improve one and by doing so you can seek aid in one or many of the sessions.
- Sun Feb 03, 2019 10:49 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Midterm
- Replies: 12
- Views: 2081
Re: Midterm
Yes, doing all of the homework questions help a lot because you'll realize what you need to improve one and by doing so you can seek aid in one or many of the sessions.
- Wed Dec 05, 2018 9:10 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape
- Replies: 5
- Views: 526
Shape
When asked for the shape, are we always supposed to say the molecular geometry rather than the electronic geometry?
- Wed Dec 05, 2018 9:08 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent Structures
- Replies: 12
- Views: 1209
Re: Bent Structures
Yes, they are all polar.
- Wed Dec 05, 2018 9:04 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted Versus Lewis
- Replies: 4
- Views: 451
Re: Bronsted Versus Lewis
One of the UA told me they were the same thing.
- Sun Dec 02, 2018 6:32 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: 4.73
- Replies: 2
- Views: 607
4.73
(a) Draw a Lewis structure for each of the following species: CH3 ; CH4; CH3 ; CH2; CH22 ; CH22 . (b) Identify each as a radical or not.
How do you identify if they're radicals or not?
How do you identify if they're radicals or not?
- Thu Nov 29, 2018 9:50 pm
- Forum: Naming
- Topic: Coordination Number
- Replies: 3
- Views: 389
Re: Coordination Number
The coordination number equals the number of ligands.
- Thu Nov 29, 2018 9:49 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 4.72
- Replies: 2
- Views: 279
4.72
Why is NO3- nonpolar?
- Thu Nov 29, 2018 8:56 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma bonds
- Replies: 6
- Views: 729
Re: Sigma bonds
They go head to head.
- Thu Nov 29, 2018 8:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 6th edition 4.23
- Replies: 3
- Views: 692
Re: 6th edition 4.23
Yes you did but it's not the molecular formula but VSEPR formula.
- Thu Nov 29, 2018 8:38 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Determining polar and non polar molecules from a lewis structure
- Replies: 8
- Views: 2686
Re: Determining polar and non polar molecules from a lewis structure
By the electronegativity difference between the atoms. If they cancel each other then it's non polar.
- Tue Nov 27, 2018 11:02 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: 4.46
- Replies: 4
- Views: 539
Re: 4.46
KylieY_3B wrote:I believe it's for the entire molecule.
Okay! Thank you!
- Tue Nov 27, 2018 11:00 pm
- Forum: Resonance Structures
- Topic: Bond lengths & number of resonance structures
- Replies: 3
- Views: 629
Re: Bond lengths & number of resonance structures
https://www.youtube.com/watch?v=dudRIG-dRE4
That video might help clarify resonance structures and bond lengths.
That video might help clarify resonance structures and bond lengths.
- Tue Nov 27, 2018 10:45 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: pi bond
- Replies: 4
- Views: 395
Re: pi bond
So just to clarify, as long as there's resonance then there's delocalized pi bond?
- Tue Nov 27, 2018 10:38 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: 4.17
- Replies: 3
- Views: 412
4.17
Predict the bond angles at the central atom of the following molecules and ions: (a) ozone, O3; (b) azide ion, N3 ; (c) cyanate ion, CNO ; (d) hydronium ion, H3O . For part a.) For the lewis structure of O3, why isn't there double bonds connecting both the oxygen to the oxygen with the lone pair? Al...
- Tue Nov 27, 2018 10:21 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: 4.46
- Replies: 4
- Views: 539
4.46
4.46 Describe the structure of the formamide molecule, HCONH2, in terms of hybrid orbitals, bond angles, and sigma and pi bonds. The C atom is bonded to one H atom, a terminal O atom, and the N atom. The N atom is also bonded to two H atoms. Do you get the sigma and pi bonds for the entire molecule ...
- Mon Nov 26, 2018 5:01 pm
- Forum: General Science Questions
- Topic: Test 3
- Replies: 4
- Views: 471
Re: Test 3
I heard that today's lecture was also included.
- Mon Nov 26, 2018 3:05 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: CH2CHCN geometry
- Replies: 3
- Views: 9541
Re: CH2CHCN geometry
So for this problem we don't describe the hybrid orbitals on each carbon atom? Or by describing the CH2 we identify the hybrid orbital of Acrylonitrile?
- Mon Nov 26, 2018 1:38 pm
- Forum: Hybridization
- Topic: Test 3
- Replies: 13
- Views: 1063
Re: Test 3
The test covers everything up to Monday's lecture even if your discussion is on Tuesday. Just wanted to clear things up! Since in the past he has put material on the test from the lecture on Monday so now I know to study up to Monday lecture ! Thanks! Are we supposed to know everything he went over...
- Sun Nov 25, 2018 11:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shape
- Replies: 4
- Views: 394
Re: Molecular Shape
I think you should use the formal charge when dealing with Lewis structures so you don't loose the habit.
- Sun Nov 25, 2018 10:57 pm
- Forum: Lewis Structures
- Topic: 4.7A Homework
- Replies: 3
- Views: 1174
Re: 4.7A Homework
If I'm not mistaken oxygen has a double bond with sulfur.
- Sun Nov 25, 2018 10:46 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 4.5 Bond Angle
- Replies: 2
- Views: 160
4.5 Bond Angle
b) What is the expected OClO bond angle?
Do you go from oxygen to oxygen and say it's less than 120 degrees?
Do you go from oxygen to oxygen and say it's less than 120 degrees?
- Fri Nov 16, 2018 1:52 pm
- Forum: Hybridization
- Topic: Describing Hybridization
- Replies: 3
- Views: 385
Re: Describing Hybridization
There's a chart in 4.2 that has the electron arrangement, number of atomic orbitals, hybridization of the central atom, and the number of hybrid orbitals. It can be helpful since it gives a breakdown.
- Fri Nov 16, 2018 1:44 pm
- Forum: Hybridization
- Topic: General definition/context
- Replies: 2
- Views: 322
Re: General definition/context
You use hybridization to explain molecular geometry hence:
linear → sp
trigonal planar → sp²
tetrahedral → sp³
trigonal pyramidal → sp³d
octahedral → sp³d²
linear → sp
trigonal planar → sp²
tetrahedral → sp³
trigonal pyramidal → sp³d
octahedral → sp³d²
- Fri Nov 16, 2018 1:33 pm
- Forum: Hybridization
- Topic: How to Determine
- Replies: 12
- Views: 1060
Re: How to Determine
Note:
Single bonds--> one sigma bond
Double bonds--> one sigma and one pie.
Triple bonds--> one sigma and two pies.
Single bonds--> one sigma bond
Double bonds--> one sigma and one pie.
Triple bonds--> one sigma and two pies.
- Thu Nov 15, 2018 11:49 pm
- Forum: Hybridization
- Topic: How to Determine
- Replies: 12
- Views: 1060
Re: How to Determine
I don't think resonance affects it but Im not certain. That being said hybridization to explain molecular geometry.
linear → sp
trigonal planar → sp²
tetrahedral → sp³
trigonal pyramidal → sp³d
octahedral → sp³d²
linear → sp
trigonal planar → sp²
tetrahedral → sp³
trigonal pyramidal → sp³d
octahedral → sp³d²
- Thu Nov 15, 2018 11:41 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Molecular Orbital Diagram
- Replies: 4
- Views: 722
Re: Molecular Orbital Diagram
So we don't need to know how to draw the 3D shape right?
- Sun Nov 11, 2018 9:50 pm
- Forum: Dipole Moments
- Topic: Dipoles
- Replies: 2
- Views: 275
Dipoles
Just for clarification, a partially positive element does not mind sharing electrons while a partially negative receives the electrons?
- Sun Nov 11, 2018 9:41 pm
- Forum: Dipole Moments
- Topic: Bond Lengths
- Replies: 5
- Views: 573
Re: Bond Lengths
The atomic size can increase the bond length.
- Sun Nov 11, 2018 9:32 pm
- Forum: Student Social/Study Group
- Topic: Study Group Chat?
- Replies: 4
- Views: 615
Re: Study Group Chat?
I do not know if there's a study group but I wouldn't mind forming a study group.
- Wed Oct 10, 2018 11:34 pm
- Forum: Properties of Light
- Topic: Photoelectric effect
- Replies: 1
- Views: 211
Re: Photoelectric effect
Wait..I was confused. The work function and avogrado's number is for part b. So it all works out.
- Wed Oct 10, 2018 11:30 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical & Molecular Formulas
- Replies: 11
- Views: 1462
Re: Empirical & Molecular Formulas
Yes, the empirical and molecular can defiantly be the same.
- Wed Oct 10, 2018 11:27 pm
- Forum: Properties of Light
- Topic: Photoelectric effect
- Replies: 1
- Views: 211
Photoelectric effect
28. Light hits a sodium metal surface and the velocity of the ejected electron is 6.61 x 105 m.s-1. The work function for sodium is 150.6 kJ.mol-1. A. What is the kinetic energy of the ejected electron? I used the fromula EK=1/2 MV^2 and got 1.99*10^-19 but I don't understand how to apply the work f...
- Fri Oct 05, 2018 4:13 pm
- Forum: Properties of Light
- Topic: Homework Question
- Replies: 2
- Views: 281
Homework Question
For Tuesday, do we have to turn in seven problems that relate to quantum?
- Wed Oct 03, 2018 8:39 pm
- Forum: SI Units, Unit Conversions
- Topic: Homework Grading Clarification [ENDORSED]
- Replies: 8
- Views: 847
Re: Homework Grading Clarification [ENDORSED]
We're encouraged to do as many as we can but to make it easier for the TAs we should only turn in the seven we want graded.