Search found 26 matches
- Mon Mar 13, 2017 12:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam points
- Replies: 7
- Views: 1642
Re: Final Exam points
Following up on on the mention about the points for posting on Chemistry Community, does anyone know if posting twice one week could replace the point of another week of not posting? I wasn't able to post last week bc I didn't have Wi-Fi at home and my phone wasn't working. thanks in advance! I don...
- Mon Mar 13, 2017 12:42 pm
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Strains
- Replies: 2
- Views: 672
Re: Strains
You can refer to this to see the difference between the two strains! http://web.chem.ucla.edu/~harding/notes/strain_01.pdf But basically, I believe that torsional strains are steric strains that occurs when there are eclipsed or gauche interactions, so they are similar to each other.
Re: "Iso"
It has "iso" because of its formation. The two carbons are connected to one at the same time rather than each connected to one another. If it was connected to each other like C--C--C in a chain, then you would call it propyl, but since it's 2 carbons connected to one, then it's isopropyl. ...
- Fri Mar 10, 2017 8:17 am
- Forum: *Alkanes
- Topic: IUPAC naming for 3 identical substituents
- Replies: 1
- Views: 591
Re: IUPAC naming for 3 identical substituents
That looks correct!
- Mon Feb 27, 2017 12:42 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Pre-Equilibrium approach
- Replies: 1
- Views: 379
Re: Pre-Equilibrium approach
As Chem_mod replied in another post: "You don't need to use the pre-equilibrium approach if the first step is a slow step. Remember, the slow step is the rate-determining step and a pre-equilibrium is when an intermediate is formed in a fast equilibrium reaction prior to a slow step in the mech...
- Thu Feb 23, 2017 1:26 pm
- Forum: First Order Reactions
- Topic: Question About the 1st Order REaction Rate Law
- Replies: 2
- Views: 684
Re: Question About the 1st Order REaction Rate Law
I think you're talking about the differential rate laws because for the first order rate law, you just have to work with initial and final concentration, one of which is usually given to you. But for the differential rate laws, which I think the question is referring to, then yes you have to always ...
- Tue Feb 14, 2017 3:41 am
- Forum: Balancing Redox Reactions
- Topic: 2016 Midterm Q3
- Replies: 1
- Views: 458
Re: 2016 Midterm Q3
If you look back at pg. 30 in the course reader,for ideal gas, delta U = 3/2*n*R*delta T and since it is isothermal, meaning that there is no temperature change, then delta T = 0. It being 0 then makes delta U = 0 also.
- Tue Feb 14, 2017 3:26 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: midterm 2015 Q7
- Replies: 3
- Views: 632
Re: midterm 2015 Q7
Ethan Frankel 2C wrote:Yep! The reactant/cathode will be the higher concentration, and the lower concentration is the anode.
Can you explain why this is so?
- Mon Feb 06, 2017 12:43 pm
- Forum: Balancing Redox Reactions
- Topic: Intensive Property
- Replies: 2
- Views: 680
Re: Intensive Property
Since intensive property "is a physical property of a system that does not depend on the system size or the amount of material in the system," voltage is an intensive property because it does not change due to the size of the electrode or the amount of electrons transferred. What it depend...
- Sun Feb 05, 2017 2:50 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2763462
- Mon Jan 23, 2017 12:39 pm
- Forum: Calculating Work of Expansion
- Topic: R vs. kB
- Replies: 1
- Views: 556
Re: R vs. kB
Hi, I believe that you generally use it when you calculate for entropy if it concerns degeneracy (W) and arrangements of molecules. For example, in the textbook, question 9.21 asks to calculate the entropy of a solid nanostructure made of 64 molecules in which the molecules (a) are all aligned in th...
- Tue Jan 17, 2017 8:43 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat/Temperature
- Replies: 1
- Views: 400
Re: Heat/Temperature
Hi, In thermodynamics terms, temperature indicates random motion of particles, while heat is the transfer of energy due to temperature differences. Usually, you're asked to solve for heat at constant pressure or delta H (units is kJ or kJ/mol), whereas temperature is usually part of the calculations...
- Sun Jan 15, 2017 12:37 am
- Forum: Student Social/Study Group
- Topic: Bar Vs. Atmosphere
- Replies: 1
- Views: 604
Re: Bar Vs. Atmosphere
Hi,
Looking at some of the practice midterms and finals questions in the back, I noticed that some of the answers provided use atm (pg.131 & 181), so I'm assuming that we should use atm for pressure!
Looking at some of the practice midterms and finals questions in the back, I noticed that some of the answers provided use atm (pg.131 & 181), so I'm assuming that we should use atm for pressure!
- Wed Nov 30, 2016 12:47 pm
- Forum: General Science Questions
- Topic: Sig Figs
- Replies: 3
- Views: 1013
Re: Sig Figs
I usually try to not round until the final answer, so throughout my calculations, I leave all the numbers in, even if it is long. It may be a bit meticulous, but by doing this, I've never had problems with sig figs on my quizzes and midterm. I think it's usually safe though to leave 4 numbers in aft...
- Tue Nov 22, 2016 4:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: How do you know if it's Kc or Kp??
- Replies: 1
- Views: 472
Re: How do you know if it's Kc or Kp??
I believe you use Kp because when dealing with gases, you are dealing with pressure, not molar concentration like you would with aqueous ones.
- Wed Nov 16, 2016 8:49 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Ligands and Coordination Numbers
- Replies: 2
- Views: 727
Re: Ligands and Coordination Numbers
Hi, Yes! You need to know how many bonds each ligand can make so that you can find out the coordination number. In the course reader, the ones with an asterisk next to them are polydentates, meaning that they can make 2 or more bonds; you just have to memorize which makes how many. For example, for ...
- Sun Nov 13, 2016 8:23 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Are the coordination numbers just inside of brackets? [ENDORSED]
- Replies: 4
- Views: 1317
Re: Are the coordination numbers just inside of brackets? [ENDORSED]
Hi,
The coordination number is just what is inside the bracket!
The coordination number is just what is inside the bracket!
- Tue Nov 01, 2016 11:07 am
- Forum: Hybridization
- Topic: Hybridization
- Replies: 2
- Views: 560
Hybridization
Can someone please explain to me the whole concept of hybridization and when molecules get hybridized? Thank you!
- Fri Oct 28, 2016 12:34 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic character
- Replies: 1
- Views: 422
Re: Ionic character
Hi Angela, The higher an element's electronegativity is, the more likely it is to create a bond with great ionic character. To compare compounds' ionic character, you would usually find the electronegativity difference between the elements. You can also usually do this on the periodic table by knowi...
- Tue Oct 18, 2016 12:20 pm
- Forum: Student Social/Study Group
- Topic: De Neve Study Group
- Replies: 35
- Views: 4510
Re: De Neve Study Group
Jordan Sandoval 4L wrote:Khang_Tran_4C wrote:I'm in Holly! We should meet up to do go over homework problems together
I'm fine with Sunday's for review.
I live in Holly and I would like to study with anyone else who lives here. It's been tricky finding other first years in the building.
What floor are you on Holly?
- Tue Oct 18, 2016 12:16 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Ch.1 Problem 43
- Replies: 2
- Views: 752
Re: Ch.1 Problem 43
Thank you Brandon
- Tue Oct 18, 2016 12:15 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 2763462
Re: Post All Chemistry Jokes Here
Lost an electron?
Better keep anion it ;)
Better keep anion it ;)
- Tue Oct 11, 2016 11:33 am
- Forum: Molarity, Solutions, Dilutions
- Topic: Quiz 1 Prep
- Replies: 2
- Views: 597
Re: Quiz 1 Prep
Hi,
You would convert both masses to moles, but also convert both of them into mol Ca so that you can add the two values of mol together. You can then take the result of the addition and divide it by 0.400L to find the molarity. After finding molarity, you can compare it to 5.30X10^-3 M.
You would convert both masses to moles, but also convert both of them into mol Ca so that you can add the two values of mol together. You can then take the result of the addition and divide it by 0.400L to find the molarity. After finding molarity, you can compare it to 5.30X10^-3 M.
- Fri Oct 07, 2016 1:58 pm
- Forum: General Science Questions
- Topic: Formula Sheet
- Replies: 3
- Views: 1195
Re: Formula Sheet
My TA said that they will give us a sheet with formulas, constants, and elements on it for the quiz!
- Thu Oct 06, 2016 11:17 am
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Ch.1 Problem 43
- Replies: 2
- Views: 752
Ch.1 Problem 43
Hi everyone, So this problem states: "What is the minimum uncertainty in the speed of an electron confined to within a lead atom of diameter 350. pm? How would you model the atom as a one-dimensional box with a length equal to the diameter of the actual atom?" I got the answer to the first...
- Thu Sep 29, 2016 11:11 am
- Forum: Student Social/Study Group
- Topic: De Neve Study Group
- Replies: 35
- Views: 4510
Re: De Neve Study Group
I'm in Holly! We should meet up to do go over homework problems together
I'm fine with Sunday's for review.
I'm fine with Sunday's for review.