Search found 20 matches
- Sat Mar 12, 2016 12:14 pm
- Forum: *Cycloalkanes
- Topic: Two cycloalkanes attached to each other
- Replies: 12
- Views: 6417
Re: Two cycloalkanes attached to each other
What's the difference between using phenyl and benzyl when naming structures that have cyclohexanes connected to longer carbon chains(therefore making the cyclohexane the substituent). We won't be expected to use phenyl or benzyl; rather if you have a cyclic substituent like cyclohexane or cyclopro...
- Sat Mar 12, 2016 12:06 pm
- Forum: *Cycloalkanes
- Topic: Two cycloalkanes attached to each other
- Replies: 12
- Views: 6417
Re: Two cycloalkanes
On quiz 3, they asked us to draw the line structure of (C6H11)C(CH3)3, so I drew a cyclohexane with a tert-propyl attached to it. However, they wanted the systematic name so I wrote down (1,1-dimethylethyl)cyclohexane and I got marked wrong on the dimethylethyl part, specifically the ethyl part. Wh...
- Sat Mar 12, 2016 11:54 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 2013 Final 1b Entropy Change
- Replies: 1
- Views: 438
2013 Final 1b Entropy Change
In this problem we are given a balloon filled with .13 moles of helium into the air. as the balloon rises, the temperature of the helium decreases and the balloon expands due to the decrease in external temperature and pressure at higher altitudes. If the helium in the balloon started at 3.0 L and 2...
- Sun Feb 28, 2016 12:12 am
- Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
- Topic: Another possible constitutionl isomer?
- Replies: 4
- Views: 813
Re: Another possible constitutionl isomer?
Cindy Chen_2I wrote:What you draw is the same isomer as the one right next to it.
If you try to name it, you'll see that they're both named 2-Methyl-1-butene
I do see that now, since that is the case, could my drawing potentially be described as geometric isomer though? Would it be trans (E)?
- Sat Feb 27, 2016 11:32 pm
- Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
- Topic: Another possible constitutionl isomer?
- Replies: 4
- Views: 813
Another possible constitutionl isomer?
I drew in another potential constitutional isomer to the right of the book answers on number 1.23, can someone explain why this does not count as an answer? Why can't the double bond be at the end right before the substituent?
See image.
See image.
- Sat Feb 27, 2016 11:01 pm
- Forum: *Cycloalkenes
- Topic: Naming Cycloalkenes
- Replies: 1
- Views: 709
Naming Cycloalkenes
When naming cycloalkenes, are the numbers of the double bonds prioritized over the numbering of substituents? For example the molecule 5-methyl-1,3-pentadiene could be called 3-methyl-1,4-pentadiene which would be lower numbers (1,3,4) than the true naming (1,3,5). Is this because you look at double...
- Sat Feb 27, 2016 10:38 pm
- Forum: *Cycloalkanes
- Topic: Substituent naming
- Replies: 1
- Views: 459
Substituent naming
When ordering substituents alphabetically, are the prefixes di- and tri- (such as in dimethyl) included in the alphabetization? With regards to common names, iso and neo (arbitrarily?) influence the alphabetic priority, but sec and tert do not. Can someone explain in which cases, if any, greek prefi...
- Fri Feb 26, 2016 1:28 pm
- Forum: *Alkynes
- Topic: Alkyne Structural Formula
- Replies: 1
- Views: 482
Alkyne Structural Formula
For the molecule 4-methyl-1-pentyne, the answer is given to be CH C CH2 (CH3) CH3 with parentheses to show the methyl substituent. Would it be wrong to write the structural formula as CH C CH2 CH (CH3)2 ? I'm sure I have seen this notation on a few other questions to denote the two possible branches...
- Thu Feb 25, 2016 5:05 pm
- Forum: *Alkanes
- Topic: Structural Formula parentheses
- Replies: 2
- Views: 665
Structural Formula parentheses
I normally associated Using parentheses in structural formulas to simply group together long chains of the same molecule like (CH2)5 or so. But in certain cases, molecules from two separate branches are grouped together within parentheses, or only a single molecule is in parentheses; which goes agai...
- Thu Feb 25, 2016 12:08 am
- Forum: *Alkanes
- Topic: Substituent question
- Replies: 1
- Views: 612
Re: Substituent question
When looking at alkanes, you first find the longest chain of carbons, this length will give you the root name to use like methane, ethane, propane, etc. Next, you look at what branches off the path of this main chain, which will be your constituents. The way you determine your constituent number is ...
- Wed Feb 24, 2016 11:45 pm
- Forum: *Alkanes
- Topic: Condensed Structural Formulas
- Replies: 1
- Views: 455
Condensed Structural Formulas
For Self Test 1.4A a) in the "Introduction to Organic Chemistry" Reader, the question asks, "Write the structural formula for 2-methylpentane." I began by drawing a line structure to visualize the hydrocarbon, and then for my structural formula answered: (CH3)2 CH (CH2)2 CH3 The ...
- Mon Feb 15, 2016 9:42 am
- Forum: General Rate Laws
- Topic: Units of constant (k) for different overall rxn orders
- Replies: 1
- Views: 452
Units of constant (k) for different overall rxn orders
It would seem that depending on the order of the reaction, the units of the k constant changes. Is it safe to assume that the EXPONENTS of the units of k (liters/mol x seconds) will always equal (overall reaction order number minus 1) ? Such as in the book for number 15.17, a reaction involving [A] ...
- Fri Feb 12, 2016 1:40 am
- Forum: General Rate Laws
- Topic: Half Life for 1st Order Reaction
- Replies: 1
- Views: 480
Half Life for 1st Order Reaction
Does the Half Life T(1/2) always equal 0.693/k for any given first order reaction? By what method would you be able to solve for the constant k?
- Thu Feb 04, 2016 4:14 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Regarding the salt bridge concept
- Replies: 1
- Views: 622
Regarding the salt bridge concept
In a galvanic cell I am aware that the salt bridge is used to maintain the gradient of electrons flowing into the positively charged cathode; can someone explain to me the method by which the salt bridge maintains this gradient? If, for example a zinc electrode Zn(s)+2e > Zn^(2+) is being oxidized b...
- Sun Jan 31, 2016 6:20 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagram Understanding
- Replies: 1
- Views: 412
Cell Diagram Understanding
If the double lines on a cell diagram represent the salt bridge, does that mean one side represents the anode and the other the cathode? And does the order of the elements within a phase change (single line, not double) matter on a cell diagram?
Thank you.
Thank you.
- Wed Jan 27, 2016 1:35 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Question Regarding K and Q
- Replies: 2
- Views: 607
Question Regarding K and Q
For the formula Delta G = Delta G Nought + RTlnQ could someone help clarify the difference between the constants K and Q? since they are supposed to represent (Conc. of Products) / (Conc. of Reactants) right?
- Thu Jan 21, 2016 9:36 pm
- Forum: Phase Changes & Related Calculations
- Topic: Delta H Nought vs Delta H
- Replies: 3
- Views: 1951
Delta H Nought vs Delta H
Could somebody help explain to me the difference between Delta H Nought and Delta H? As well as whether these values are usually expressed in kj or kj/mol?
- Sun Jan 10, 2016 10:51 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Extensive and Intensive Properties
- Replies: 1
- Views: 469
Re: Extensive and Intensive Properties
We can use the example of heat capacity vs specific heat capacity as shown in the course reader to explain intensive and extensive properties. An extensive property only reveals information about a particular case, such as the heat capacity of a certain amount of substance, which would be the amount...
- Sat Nov 28, 2015 11:47 pm
- Forum: Trends in The Periodic Table
- Topic: Video: Electronegativity, Ionization Energy, Ionic Radii
- Replies: 3
- Views: 972
Video: Electronegativity, Ionization Energy, Ionic Radii
Here is a video describing fundamental periodic trends along with the reasoning behind each trend.
- Sun Oct 04, 2015 11:32 pm
- Forum: Significant Figures
- Topic: Rounding when it comes to 5
- Replies: 5
- Views: 1132
Re: Rounding when it comes to 5
As further clarification to the initial reply, I believe we round to even integers in order to prevent biasing numbers on average upward or downwards especially with large sample sizes.