Search found 33 matches
- Fri Mar 14, 2014 11:49 am
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: Trans vs. Cis
- Replies: 1
- Views: 821
Trans vs. Cis
I understand that a trans a,a chair conformation is less stable than a trans e,e chair conformation and that a cis a,e chair conformation is just as stable as a cis e,a chair conformation, but out of curiosity are the cis chair conformations (both a,e and e,a) in between those chair conformations in...
- Fri Mar 14, 2014 11:14 am
- Forum: *Ethers
- Topic: How to name ethers?
- Replies: 5
- Views: 2086
Re: How to name ethers?
Is there a case when you would have "-oxyl"?
- Fri Mar 14, 2014 11:03 am
- Forum: *Alkanes
- Topic: When to use...
- Replies: 6
- Views: 1240
Re: When to use...
Would it be accurate to think of tert- as having the "cross" at the start of the substituent and neo- as having the "cross" at the end of the substituent?
- Sun Mar 09, 2014 7:53 pm
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: Newman Projections for Cyclohexanes
- Replies: 4
- Views: 2721
Re: Newman Projections for Cyclohexanes
Thank you guys so much! This helped a lot!
- Sat Mar 08, 2014 12:31 am
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: Newman Projections for Cyclohexanes
- Replies: 4
- Views: 2721
Newman Projections for Cyclohexanes
So I was experimenting with the molecular structure model kit and was able to build both the boat and chair conformations for cyclohexane. However, I was confused as to why either of these conformations are considered stable since looking down each of the bonds, a gauche configuration appears. Does ...
- Tue Feb 25, 2014 6:02 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: to determine the overall reaction
- Replies: 6
- Views: 3213
Re: to determine the overall reaction
why is it that for the overall rate law we can leave in the concentration of OH-; shouldn't it be written off somehow because it's an intermediate?
- Sun Feb 09, 2014 9:34 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Trends in Cell (Redox) Potentials
- Replies: 3
- Views: 2915
Re: Trends in Cell (Redox) Potentials
Ah I see now! Thank you so much!!!
- Sat Feb 08, 2014 1:15 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: G = RTlnP
- Replies: 2
- Views: 3808
Re: G = RTlnP
I suppose what I’m really asking is why we are able to use the equation G= G° + (RTlnP - RTlnP°) in our derivation of the equation ΔG° = -RTlnK; where does the first equation derive from?
- Sat Feb 08, 2014 1:10 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Trends in Cell (Redox) Potentials
- Replies: 3
- Views: 2915
Trends in Cell (Redox) Potentials
On page 531, the text makes the statement that "the most negative [standard reduction potentials]...are usually found toward the left of the periodic table, and the most positive...are found toward the upper right." But the elements found on the left of the periodic table often have positi...
- Thu Feb 06, 2014 5:51 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: G = RTlnP
- Replies: 2
- Views: 3808
G = RTlnP
In lecture on Monday 1/27, we were given the equation G = G° + RTln(P/P°) as part of our derivation of the equation ΔG° = -RTlnK. I understand that another way to phrase the equation we were given is G = G° + (RTlnP - RTlnP°). This leads me to believe that G = RTlnP and I’m wondering where this equa...
- Thu Feb 06, 2014 5:34 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs' Free Energy Dependence on Constant T and Constant P
- Replies: 1
- Views: 641
Gibbs' Free Energy Dependence on Constant T and Constant P
Why is the equation for Gibbs free energy (G=H-TS) dependent on the conditions of constant temperature and constant pressure?
- Mon Jan 27, 2014 11:52 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Standard States of Entropies
- Replies: 1
- Views: 494
Standard States of Entropies
Why is it that the standard entropies of substances are those measured at 1 bar instead of 1 atm? I know that the ratio between bar and atm is practically 1, but why is bar used instead of atm?
- Mon Jan 27, 2014 11:50 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Standard Molar Entropies
- Replies: 2
- Views: 1512
Re: Standard Molar Entropies
There was also a section on page 306 in the textbook that mentioned the effect mass has on standard molar entropies. Specifically it says that "...the greater the mass of the molecules, the closer together are the energy levels." These energy levels are more "thermally accessible"...
- Mon Jan 27, 2014 10:39 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible work VS Irreversible work
- Replies: 5
- Views: 978
Re: Reversible work VS Irreversible work
Why do you say that a reversible process involves no entropy production?
- Mon Jan 27, 2014 7:40 pm
- Forum: Calculating Work of Expansion
- Topic: Reversible work VS Irreversible work
- Replies: 5
- Views: 978
Re: Reversible work VS Irreversible work
Would the only way to have a reversible process to have an isothermal situation? Would the only irreversible process be one in which you have constant pressure and a change in volume?
- Fri Jan 24, 2014 10:02 am
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Stability of a Perfect Crystal
- Replies: 3
- Views: 1027
Re: Stability of a Perfect Crystal
But what about the fact that entropy is zero as well at that point; wouldn't that imply that there's instability?
- Thu Jan 23, 2014 10:42 am
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Stability of a Perfect Crystal
- Replies: 3
- Views: 1027
Stability of a Perfect Crystal
Say you have a perfect crystal cooled down to 0 Kelvin. I understand that S=0 at this point since there is no atomic movement or vibration and that U=0 since there is no heat or work to supply internal energy. As I understand, the Entropy Maximization Principle implies that since S=0, the system is ...
- Sun Jan 19, 2014 9:19 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: The Relationship Between Entropy and Stability
- Replies: 1
- Views: 17703
The Relationship Between Entropy and Stability
From what I understand, a system is stable and at equilibrium when (1) internal energy is at its minimum and (2) entropy is at its maximum. Does this fact arise from Gibb’s free energy equation ΔG= ΔH-TΔS which would imply that a positive change in entropy would lead to a more negative change of Gib...
- Thu Nov 21, 2013 10:51 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Determining what is a chelate
- Replies: 2
- Views: 760
Re: Determining what is a chelate
How exactly does the cis and trans arrangement determine if a polydentate will form a chelating complex?
- Thu Nov 21, 2013 7:07 pm
- Forum: Naming
- Topic: Am I alphabetizing Wrong
- Replies: 5
- Views: 1282
Re: Am I alphabetizing Wrong
So any of the methods of writing the ligands is will be seen as correct on the quiz?
- Mon Nov 04, 2013 12:37 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Schematic on p. 122
- Replies: 1
- Views: 497
Schematic on p. 122
On the top right corner if page 122 is a schematic of a polyatomic orbital. How did they come up with the shapes drawn? Also, how do we know that the 1b1 orbital is nonbonding? Lastly, are we required to understand how to come up with these types of molecular orbital diagrams?
- Mon Nov 04, 2013 12:23 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Molecular Orbitals and Hybridization
- Replies: 1
- Views: 443
Molecular Orbitals and Hybridization
This is sort of a list of questions that pertain to one subject in general: I've noticed that molecular orbital theory relies less on the concept of hybridization than valence bond theory. A note on page 122 of the textbook mentioned that "molecular orbitals are built from all the available [i]...
- Mon Nov 04, 2013 12:13 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Drawing Heteronuclear Molecular Orbitals
- Replies: 1
- Views: 476
Drawing Heteronuclear Molecular Orbitals
I was watching the midterm review session podcast from last friday (11/1) and I noticed that when we were drawing a heteronuclear molecular orbital that the molecular orbitals were still symmetrical in the sense that if one drew a line down the middle, there would be symmetry. However, in the textbo...
- Mon Nov 04, 2013 12:05 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Need to know MOs for triatomic atoms?
- Replies: 3
- Views: 696
Re: Need to know MOs for triatomic atoms?
I noticed that this is one of the questions from past classes. We are still not required to know how to draw polyatomic molecular orbital diagrams, correct?
- Fri Nov 01, 2013 8:41 pm
- Forum: Hybridization
- Topic: Different Hybrid Orbital Bonds
- Replies: 3
- Views: 852
Re: Different Hybrid Orbital Bonds
The specific molecule I was working with was CH2CHCN and I was particularly interested in the sigma bond between the two carbons at the end (the carbon attached to 1 H and the carbon attached to N). I understand that the carbon attached to the hydrogen (let's call it C1) has three areas of electron ...
- Thu Oct 31, 2013 6:06 pm
- Forum: Hybridization
- Topic: Lone Pairs in Hybridized Orbitals
- Replies: 1
- Views: 512
Lone Pairs in Hybridized Orbitals
Are lone pairs in atoms with hybridized orbitals in bonds also in hybridized orbitals?
- Thu Oct 31, 2013 5:59 pm
- Forum: Hybridization
- Topic: Different Hybrid Orbital Bonds
- Replies: 3
- Views: 852
Different Hybrid Orbital Bonds
Is it possible for different types of hybrid orbitals to bond? For example, can a 2sp2 bond with an sp?
- Thu Oct 31, 2013 11:56 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 3.3b bond angle
- Replies: 1
- Views: 714
3.3b bond angle
In 3.3, we have a ClO2+ ion. From the lewis structure, I was able to determine that there are four areas of electron density with two lone pairs giving it a VSEPR formula of AX2E2. I understand that the shape would be angular and it would be bent more than the shape of a molecule with VSEPR formula ...
- Thu Oct 17, 2013 10:28 pm
- Forum: Significant Figures
- Topic: Significant Figures in regards to energy states
- Replies: 3
- Views: 1146
Re: Significant Figures in regards to energy states
What if they are the only information given? For example, the question asks what is the energy released when an electron jumps down from n=4 to n=1 and the integers were the only information given; how many sig figs should our answer have?
- Thu Oct 17, 2013 7:01 pm
- Forum: Significant Figures
- Topic: Significant Figures in regards to energy states
- Replies: 3
- Views: 1146
Significant Figures in regards to energy states
If asked to calculate the energy of electrons in n-energy levels and just given values such as n=4 and n=1, how many sig figs should be in our answer? I've noticed in the workbook that the answer generally has 3 sig figs, but other than that I have no clue how many sig figs to leave in the answer.
- Thu Oct 17, 2013 6:51 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Radial Distribution
- Replies: 1
- Views: 451
Radial Distribution
From what I understand from the text, the radial distribution pertains to the likelihood of finding an electron within a certain radius. When it says “in the range of radii Sr”, does it talk of only locations that are that particular distance from the nucleus or of any location within the boundaries...
- Thu Oct 17, 2013 6:50 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: 1s-orbital in He^+ vs. 1s-orbital in H
- Replies: 1
- Views: 709
1s-orbital in He^+ vs. 1s-orbital in H
Both He^+ and H would have 1 electron in the s-orbital, correct? Would the only difference between the two be that the s-orbital of He^+ would be closer to the nucleus since there is a higher effective nuclear charge than in H?
- Thu Oct 17, 2013 6:46 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Bohr Radius
- Replies: 1
- Views: 496
Bohr Radius
What is the Bohr radius exactly?