Search found 28 matches

by Kim Vu 2G
Sat Mar 12, 2016 12:49 pm
Forum: *Nucleophiles
Topic: Final 2013
Replies: 1
Views: 250

Final 2013

For question 6a, why isn't it considered a trans/cis molecule since it has a double bond and the methyl group is on the opposite side of the ch2 so wouldn't it be E?
by Kim Vu 2G
Sat Mar 05, 2016 4:48 pm
Forum: *Alkynes
Topic: Alkene and Alkyne
Replies: 2
Views: 691

Alkene and Alkyne

When naming organic molecules, why does the alkene get numbering priority before the alkyne?
by Kim Vu 2G
Fri Feb 26, 2016 2:21 pm
Forum: *Amines
Topic: Amines
Replies: 1
Views: 232

Amines

For amines, in the course reader, it says that an R group connected to NH2 is a primary structure, so type would CH3CH2NH3(ethyl ammine) be? And just for clarification, is the ammine group always N connected to one or more C?
by Kim Vu 2G
Thu Feb 25, 2016 9:37 pm
Forum: *Identifying Primary, Secondary, Tertiary, Quaternary Carbons, Hydrogens, Nitrogens
Topic: Trans and Cis
Replies: 2
Views: 376

Trans and Cis

Can you determine trans and cis geometric isomers just by using the line structure, if so, how would you do that? or would you have to draw out the lewis structure?
by Kim Vu 2G
Sat Feb 20, 2016 1:36 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Difference between catalysts and intermediates
Replies: 1
Views: 256

Re: Difference between catalysts and intermediates

NO2 is an intermediate because by definition, an intermediate is a substance that is produced in one step and then used up in another step of the reaction mechanism. NO2 here matches this definition as it is produced in the first step and then used up in the second step. NO however is a catalyst bec...
by Kim Vu 2G
Sat Feb 13, 2016 3:30 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Phase Change and Enthalpy
Replies: 1
Views: 329

Re: Phase Change and Enthalpy

For the midterm, I did not add a phase change because the substance was not water and so you wouldn't be able to know the enthalpy of fusion since it was not given. It depends on how much temperature the change is say water going from -10 to 110 degrees Celsius, there are going to be phase changes f...
by Kim Vu 2G
Sun Feb 07, 2016 6:20 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 2011 midterm Q6 B
Replies: 1
Views: 165

Re: 2011 midterm Q6 B

yes you multiply two to Rb because you have to balance the charges of the electrons from F2+2e--->2F, so that the electrons cancel out and you are left with a balanced equationl of F2+2Rb--->2F- + 2Rb+
by Kim Vu 2G
Sun Feb 07, 2016 6:10 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: logQ vs lnQ
Replies: 1
Views: 785

Re: logQ vs lnQ

I have used both equations too and have received the same answers for both,which you should have but I don't you will be marked off if you used the logQ equation because essentially it should lead you to the answer unless on the midterm it says specifically to use the nernst equation in the ln form.
by Kim Vu 2G
Wed Feb 03, 2016 7:22 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.17 textbook problem
Replies: 2
Views: 389

Re: 14.17 textbook problem

I have a follow up question to this problem. So I noticed that in the solution's manual, there is no presence of Cl anywhere in the reaction. Is this because the Cl has completely dissociated due to the acidity of the reaction?
by Kim Vu 2G
Wed Feb 03, 2016 7:16 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Anode and Cathode
Replies: 1
Views: 360

Re: Anode and Cathode

it is important to determine the anode and cathode because when you are writing the galvanic cell, it is easiest to write the diagram flowing from anode to cathode as the book and the solution's manual does it, and theres not really a trick but when you write out the half reactions, the side with th...
by Kim Vu 2G
Wed Feb 03, 2016 7:11 pm
Forum: Balancing Redox Reactions
Topic: Standard reduction potentials
Replies: 2
Views: 326

Re: Standard reduction potentials

you don't multiply the value of the e cell because the E represents the cell's potential under standard conditions being at 25 C, 1 atm, and one mole and so even if you multiply and change the amount of moles, the value of the e cell would still wouldn't change and this isn't like hess's law where y...
by Kim Vu 2G
Wed Feb 03, 2016 7:03 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: homework 14.15
Replies: 1
Views: 219

homework 14.15

c. Cd(s)+2Ni(OH)3(s)--->Cd(OH)2(S)+2Ni(OH)2 I have a question with writing the galvanic cell diagram because I found the half reaction correctly just like the course reader but for the galvanic cell, the course reader had Koh(aq) on the anode side. I was wondering why Koh is needed and why is it the...
by Kim Vu 2G
Tue Jan 26, 2016 9:39 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Quiz 1 Prep
Replies: 1
Views: 1614

Quiz 1 Prep

For #6, What mass of propane, C3H8, must be burned to supply 2580 kJ of heat? The standard enthalpy of combustion of propane at 298K is -2220kJ/mol. I'm not sure how to approach this problem after writing out the combustion reaction.
by Kim Vu 2G
Tue Jan 26, 2016 8:47 pm
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: Determining Residual Entropy in Crystal Form
Replies: 7
Views: 983

Re: Determining Residual Entropy in Crystal Form

I understand the calculations here, but just a general question to find the degeneracy. Do you just have to manually draw all the lewis structures for the molecule to find the degeneracy or is there another way?
by Kim Vu 2G
Tue Jan 12, 2016 10:52 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.31 heat released by Krypton gas
Replies: 3
Views: 705

8.31 heat released by Krypton gas

Calculate the heat released by 5.025g of Kr at .4 atm as it cools from 97.6 degrees to 25 degrees at a)constant pressure, b)constant volume. Assume that krypton behaves as an ideal gas. For part a, why is the molar heat capacity 10.8J/mol*C and part b 12.5 J/mol*C? Does it have to do with ratio of s...
by Kim Vu 2G
Mon Jan 11, 2016 10:58 pm
Forum: Phase Changes & Related Calculations
Topic: Exothermic reaction
Replies: 3
Views: 285

Exothermic reaction

Why is it that when the temperature increases in an enthalpy problem, it is an exothermic reaction instead of endothermic?Wouldn't the increase from initial to final temperature make the system endothermic because heat is being absorbed by the system?
by Kim Vu 2G
Sat Jan 09, 2016 4:05 pm
Forum: Phase Changes & Related Calculations
Topic: Open, Closed, or Isolated Systems
Replies: 6
Views: 2884

Re: Open, Closed, or Isolated Systems

open system is when energy and matter of the system is exchanged with the surroundings. A closed system is when there is a fixed amount of matter in the system but still can exchange energy with its surrounding and an isolated system is when the system has no contact or exchange with its surrounding...
by Kim Vu 2G
Sat Dec 05, 2015 8:14 am
Forum: Hybridization
Topic: Final 2010 Q3A
Replies: 1
Views: 278

Re: Final 2010 Q3A

if you add up all the electrons from argon plus 4 from the 3d, you should have 22 electrons leaving you at Titanium. With a metal with a cation of 2+ that means that 2 electrons have previously been subtracted away from it leaving it with titanium with 2 less electrons. So to find the original state...
by Kim Vu 2G
Sat Nov 28, 2015 11:04 pm
Forum: Ideal Gases
Topic: Equilibruim
Replies: 1
Views: 402

Equilibruim

For homework question 11.67."The reaction 2HCL<->H2 + Cl2 has K=3.2 x 10^-34 at 298 K. The initial partial pressures are H2, 1 bar; HCl 2 bar and Cl2 at 3 bar at equilibrium there is 1 mol H2. What is the volume of the container?" Why is there a new initial state of pressure in this equati...
by Kim Vu 2G
Thu Nov 19, 2015 1:12 pm
Forum: Naming
Topic: Writing coordination compound formulas
Replies: 2
Views: 913

Re: Writing coordination compound formulas

For pentaamminechloronickel (III) chloride, both of the formulas of [Ni(NH3)5Cl]Cl2 and [NiCl(NH3)5]Cl2 work and for the naming ligand, the letter a in ammine comes before the letter c in chloro so ammine gets named before chloro.
by Kim Vu 2G
Wed Nov 11, 2015 1:28 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate Using Lewis Structures
Replies: 1
Views: 343

Re: Polydentate Using Lewis Structures

I think its just helpful to know the Lewis structure because to figure out the binding of the ligand to the central atom, you need to know how many lone pairs and bond pairs it has to be available for binding. When a ligand is bidentate, it means that they have two donor atoms which allow them to bi...
by Kim Vu 2G
Fri Nov 06, 2015 10:32 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Octet Rule
Replies: 3
Views: 440

Re: Octet Rule

If it does not obey the octet rule, it can have more than 8 electrons on the central atom depending on the element because some transition metals can have up to 18 electrons because of the extra shells that can be filled in the d block so it just really depends on the atom itself.
by Kim Vu 2G
Wed Oct 28, 2015 10:58 pm
Forum: Octet Exceptions
Topic: Double bonds on group 17 atoms
Replies: 2
Views: 689

Re: Double bonds on group 17 atoms

Yes, groups 17 atoms can form double and triple bonds, depending on the element it is bonding with. Iodine only needs one more valence electron to complete its octet, however, it has the ability to expand its octet so it is possible for Iodine to have more than a single bond. I believe all group 17 ...
by Kim Vu 2G
Wed Oct 28, 2015 10:52 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent and Ionic Bonds
Replies: 2
Views: 411

Re: Covalent and Ionic Bonds

An ionic bond is usually between a metal and non-metal, where the negatively charged element with the higher ionization energy would attract the positively charged to form an octet in its valence electron. Covalent bonds are usually bonds between nonmetals in which the elements share valence electro...
by Kim Vu 2G
Wed Oct 28, 2015 6:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond angles of atoms with lone pair electrons
Replies: 1
Views: 284

Re: Bond angles of atoms with lone pair electrons

For bent, AX2E2, the bond angle is <109.5. The bond angles of seesaw would be less than 120 and 90 degrees, not 180 degrees and yes the lone pair does have a stronger repulsion than the bond pair, which is why the the angles are less than 120 and 90 degrees.
by Kim Vu 2G
Sat Oct 24, 2015 10:06 pm
Forum: Ionic & Covalent Bonds
Topic: Ground-State Electron Configurations of Ions 3.11
Replies: 2
Views: 1392

Re: Ground-State Electron Configurations of Ions 3.11

a) the electrons in the element Argon equals 18 and adding 6 more electrons from 3d^6 would make it 24 electrons, which would be chromium. However, the question is looking for a metal with 3+ ion which is means that 3 electrons were reduced from it already, so to find the element, you would add 3 mo...
by Kim Vu 2G
Thu Oct 15, 2015 11:18 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Fall 2014 Quiz 1 Preparation
Replies: 3
Views: 441

Re: Fall 2014 Quiz 1 Preparation

The answers in the workbook is telling you to use the Bohr equation which is En=-2.18*10^18 (z^2/n^2). The 2.18*10^18 is just a constant for the equation, the z is for the number of protons in the nucleus and n is the quantum level. Because the frequency was given, you can use it to find the change ...
by Kim Vu 2G
Thu Oct 08, 2015 9:54 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg's Equation
Replies: 1
Views: 250

Rydberg's Equation

The problem says, calculate the wavelength of light emitted when an electron in a hydrogen atom makes the transition from n=5 to n=3. How would you solve this equation? Using En= -hR/n^2 or v=R(1/n1 ^1) - (1/n2^2)?

Go to advanced search