Search found 18 matches
- Sun Mar 13, 2016 11:44 am
- Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
- Topic: Drawing hydrogens
- Replies: 2
- Views: 633
Re: Drawing hydrogens
It would be safer to draw out the hydrogens, but if you do, make sure to be careful what direction you draw them in. Make sure to make the axial/equatorial differences visible, with alternating up/down between each.
- Sat Mar 12, 2016 9:38 pm
- Forum: *Cycloalkanes
- Topic: Z vs E for cycloalkane with one substituent
- Replies: 1
- Views: 755
Z vs E for cycloalkane with one substituent
In Winter 2012 Final Exam, on Problem 5 Part II, it asks for the IUPAC name of molecule B, which is Z-cyclooct-4-enone. How is it considered cis- when there is only one substituent? Does the naming just default to Z when there is only one? Side question, what do you name (Z/E) when it is ambiguous (...
- Tue Mar 08, 2016 5:28 pm
- Forum: *Alkanes
- Topic: Alphabetical order for multiples
- Replies: 2
- Views: 711
Alphabetical order for multiples
When you have for example, X,Y-dimethyl and Z-ethyl, which has alphabetical priority? Is it the D in dimethyl, or E in ethyl being before the M in methyl assuming the prefix isn't factored into alpha order? Also, what do you call it when there is a di/tri-methyl in a compound (I referred to it as mu...
- Mon Mar 07, 2016 10:03 am
- Forum: *Cycloalkanes
- Topic: Naming for multiple cycloalkanes
- Replies: 2
- Views: 745
Naming for multiple cycloalkanes
How does the naming process work when there are multiple cycloalkanes of the same size? How do you prioritize which is the parent/which is the substituent, or is there a different approach? Thanks
- Mon Feb 29, 2016 3:02 pm
- Forum: *Alkanes
- Topic: Cycloalkanes
- Replies: 2
- Views: 549
Re: Cycloalkanes
Cycloalkanes also appear in ringlike structures, with cyclopropane appearing as a triangle, and cyclopentane as a pentagon (just as examples).
- Mon Feb 22, 2016 8:44 am
- Forum: *Electrophiles
- Topic: Why is F electrophile?
- Replies: 5
- Views: 1497
Re: Why is F electrophile?
F with 7 electrons has a net neutral charge, but it wants to complete its valence orbital with one more electron. The attraction of this electron makes it an electrophile. Once it has 8 electrons and a net negative charge of one, it is no longer an electrophile.
- Mon Feb 08, 2016 2:26 pm
- Forum: Balancing Redox Reactions
- Topic: Coulomb
- Replies: 4
- Views: 957
Re: Coulomb
A coulomb is an SI unit of charge, as 1C = 1A x 1s, the charge transported at a constant current one ampere in one second, and is equivalent to the charge of 6.242x10^18 electrons
- Fri Jan 29, 2016 12:12 am
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Calculating Standard Molar Entropy
- Replies: 1
- Views: 1203
Calculating Standard Molar Entropy
Is there a way to calculate the standard molar entropy of a molecule without being given any information except the standard Gibbs free energy? Thanks
- Wed Jan 20, 2016 2:12 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Enthalpy in a System
- Replies: 2
- Views: 726
Re: Enthalpy in a System
It is similar to the law of conservation of energy, in that the energy transfered (from surroundings to system or vice versa) has to be equal to the energy lost in that process.
- Mon Jan 11, 2016 2:31 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 4095948
Re: Chemistry Jokes
What was the chemist's favorite attraction at the fair?
The ferrous wheel
The ferrous wheel
- Mon Jan 11, 2016 2:27 pm
- Forum: Phase Changes & Related Calculations
- Topic: Change from Graphite to Diamond
- Replies: 2
- Views: 692
Change from Graphite to Diamond
Why is it that graphite forming into diamond is an exothermic process? Are diamonds less stable than graphite despite being so structured? Thanks
- Sat Dec 05, 2015 11:28 pm
- Forum: Naming
- Topic: Order of ligands
- Replies: 2
- Views: 703
Re: Order of ligands
To add onto that, when you writing out the name, not formula, you name ligands by alphabetical order (not including prefix). So penta-ammine would still come before cyano-
- Mon Nov 09, 2015 12:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Precipitate
- Replies: 3
- Views: 706
Re: Precipitate
A precipitate usually forms when a molecule that can dissolve in water is present, and when the solution is saturated (it hits the maximum amount of dissolved solute), then the rest of the molecule that is added remains as a solid. This can also occur after a reaction and a non-soluble molecule is c...
- Wed Nov 04, 2015 3:08 pm
- Forum: Octet Exceptions
- Topic: Boron Octet Exception HW 4.81
- Replies: 2
- Views: 953
Re: Boron Octet Exception HW 4.81
Yes, as having a completed octet is of higher priority in Lewis structures than balancing the FC. Have all atoms with filled valences first, and then balance FC to the best amount possible.
- Wed Oct 28, 2015 11:03 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Electron Configuration
- Replies: 2
- Views: 665
Re: Electron Configuration
I don't believe it matters between px and py, but I think that pz is generally assumed to be the sigma orbital, being the one that is in line between the two nuclei.
- Tue Oct 20, 2015 10:07 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: O having higher FC than N
- Replies: 1
- Views: 572
O having higher FC than N
Why is it that in [NO]+, there is a triple bond where N has an FC of 0 and O has an FC of +1 when O is more electronegative? Why doesn't it form a double bond so that N has the higher FC and O is at 0? For reference, this is 3.48.a, thanks.
- Mon Oct 19, 2015 10:25 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape under increased energy
- Replies: 1
- Views: 446
Shape under increased energy
Since the shapes (for example, tetrahedral) are in the lowest energy form, where equal electron densities are equally spread apart (at 109.5 degrees), what happens when there is an increase in energy? Can the molecule in a tetrahedral form undergo changes to the angles as energy increases, similarly...
- Sat Oct 17, 2015 7:47 pm
- Forum: Empirical & Molecular Formulas
- Topic: Compounds burned in Air
- Replies: 2
- Views: 719
Re: Compounds burned in Air
To add onto the previous response, you cannot always assume that since the g of the initial compound are given it is composed of C, H, and O. In order to determine if there is any O present in the substance being burned, you have to calculate the moles of C and H present as a result of the combustio...