When do we add an inert electrode? Do we add it to only the side that has no metal, or always to both sides even if one of cells already has a metal?
The solution manual seems to be doing it both ways. Is there any rules to this...or does it not really matter??
Search found 30 matches
- Sat Mar 12, 2016 1:47 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: inert electrodes, galvanic cells
- Replies: 1
- Views: 477
- Thu Mar 10, 2016 12:17 pm
- Forum: *Haloalkanes
- Topic: polytetrafluorotehylene
- Replies: 1
- Views: 601
polytetrafluorotehylene
How do you draw the structure of polytetrafluorotehylene? I'm confused about the ethylene part.. isn't ethylene just ethene, but in the answer key, the carbons didn't have a double bond between them.
- Wed Mar 09, 2016 8:01 pm
- Forum: *Nucleophiles
- Topic: alkyl carbanion and aryl carbanion
- Replies: 1
- Views: 584
alkyl carbanion and aryl carbanion
What are alkyl carbanion and aryl carbanion? They are mentioned in the organic textbook.... It also says carbanions have 8 valence electrons, does that just means the central carbon has a complete octet through bonding with other atoms??
- Sat Mar 05, 2016 10:52 pm
- Forum: *Alkanes
- Topic: Common Names(sec?)
- Replies: 1
- Views: 314
Common Names(sec?)
What are the common names we need to know for the final?
I know we should know iso, neo and tert since we went over those in detail in class.
What about sec? What's difference between sec and neo... they both look like T-shapes to me.
Is there any other common names we should know?
I know we should know iso, neo and tert since we went over those in detail in class.
What about sec? What's difference between sec and neo... they both look like T-shapes to me.
Is there any other common names we should know?
- Mon Feb 29, 2016 9:06 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: activated complex
- Replies: 1
- Views: 690
activated complex
HW Q15.85 The following rate laws were each derived from an elementary reaction. In each case, write the chemical equation for the reaction, determine its molecularity, and draw a proposed structure for the activated complex. (a) Rate " k[CH3CHO] (Products are CH3 and CHO.) (b) Rate " k[I]...
- Sun Feb 28, 2016 10:50 am
- Forum: Second Order Reactions
- Topic: given half life, calculate time needed
- Replies: 3
- Views: 1159
given half life, calculate time needed
HWQ 15.35 The half-life for the second-order reaction of a substance A is 50.5 s when [A]0 " 0.84 mol!L!1. Calculate the time needed for the concentration of A to decrease to (a) one sixteenth; (b) one-fourth; (c) one-fi fth of its original value. The solution manual calculated k first then use...
Re: Naming
When placing in alphabetic order, prefix such as di, tri etc is not considered.
In this case it's methyl vs. ethyl, so ethyl comes first.
In this case it's methyl vs. ethyl, so ethyl comes first.
- Thu Feb 18, 2016 2:13 pm
- Forum: *Nucleophiles
- Topic: Nucleophiles vs. Ligand
- Replies: 3
- Views: 1679
Re: Nucleophiles vs. Ligand
Nucleophile is a molecule that has a region of excess electron density.
Ligand is an ion or molecule attached to a metal atom by sharing electrons.
I guess you can think of ligand as a type of attached nucleophile :P
Ligand is an ion or molecule attached to a metal atom by sharing electrons.
I guess you can think of ligand as a type of attached nucleophile :P
- Fri Feb 12, 2016 8:03 pm
- Forum: General Rate Laws
- Topic: Given Half life, calculate initial concentration
- Replies: 1
- Views: 449
Given Half life, calculate initial concentration
HW Q 15.105 To prepare a 15-kg drug for surgery, 150 mg of the anesthetic phenobarbitol is administered intravenously. The reaction in which the anesthetic is metabolized (decomposed in the body) is first order in phenobarbital and has a half-life of 4.5 h. After about 2 h, the drug begins to lose i...
- Thu Feb 04, 2016 4:21 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Entropy change when Temperature changes [ENDORSED]
- Replies: 5
- Views: 700
Entropy change when Temperature changes [ENDORSED]
Can someone please explain when should we use the following two equations? delta S= q / T delta S = nCln (Tf / Ti) I know you should use the second one if temperature changes and the first if temp is constant. However, in hw question 9.5 Even though the temperature changed the first equ is still use...
- Fri Jan 29, 2016 10:54 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cell Setup
- Replies: 1
- Views: 477
Re: Galvanic Cell Setup
Before the electrodes are connected,SO 4 2- ion is present in both solutions. The anode solution contains ZnSO 4 and a zinc metal stripe and the cathode solution contains CuSO 4 and a copper metal strip. Both solutions are neutral. As the anode(Zn) goes through oxidization, it releases Zn 2+ into th...
- Sat Jan 23, 2016 2:17 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: 8.23 Energy put into heat calorimeter and water
- Replies: 1
- Views: 335
Re: 8.23 Energy put into heat calorimeter and water
In this question, you want to treat the calorimeter as a whole (including the water inside it and the container/machine itself), because it is asking for heat capacity which does not take volume into consideration, as opposed to specific heat capacity, which is measured per gram or mol. heat capacit...
- Sat Jan 16, 2016 11:30 pm
- Forum: Calculating Work of Expansion
- Topic: W vs w
- Replies: 1
- Views: 345
Re: W vs w
Capitalized W is degeneracy: the number of ways of achieving a given energy state, (entropy) Lower case w is work: energy transferred in or out of the system. Professor Lavelle mentioned in class that we are used to seeing work as capitalized W in high schools, however, in 14B we'll be using lower c...
- Fri Jan 08, 2016 2:39 pm
- Forum: Phase Changes & Related Calculations
- Topic: Extensive vs. Intensive Property
- Replies: 2
- Views: 2153
Re: Extensive vs. Intensive Property
intensive property - independent of the size of the sample. Ex: density, temperature, concentration Extensive property - dependent on the size of the sample. Ex: enthalpy, volume and internal energy Intensive properties would have units in the form of x/y, whereas extensive property should just have...
- Tue Dec 01, 2015 9:39 pm
- Forum: Polyprotic Acids & Bases
- Topic: HW 12.77 (Calculating pH of alanine)
- Replies: 3
- Views: 729
Re: HW 12.77 (Calculating pH of alanine)
Hi, I was wondering if this problem can be done by Ka(overall) = Ka1*Ka2, calculating the initial concentration first then used ka=x^2/ [initial] ?? I got 6.22 :( 0.11 off from the correct answer
- Mon Nov 30, 2015 11:16 am
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Why is BF3 an acid?
- Replies: 2
- Views: 1921
Why is BF3 an acid?
HW question 12.13 draw the lewis structure for each of the following species and identify each as a Lewis acid or Lewis base:
b) BF3
Why is BF3 considered a lewis acid? Doesn't B only have 3 valence electrons and will be stable with 6?
b) BF3
Why is BF3 considered a lewis acid? Doesn't B only have 3 valence electrons and will be stable with 6?
- Fri Nov 27, 2015 11:36 am
- Forum: Bronsted Acids & Bases
- Topic: Drawing the structure of conjugate acid that can be formed
- Replies: 1
- Views: 482
Drawing the structure of conjugate acid that can be formed
Hw question 12.127 The two strands of the nucleic acid DNA are held together by hydrogen bonding between four organic bases. The structure of one of these bases, thymine, is shown below. (a) How many protons can this base accept? (b) Draw the structure of each conjugate acid that can be formed. (c) ...
- Thu Nov 19, 2015 11:34 am
- Forum: Naming
- Topic: using bis, tris, tetrakis
- Replies: 4
- Views: 5584
using bis, tris, tetrakis
Can someone please explain when to use bis, tris and tetrakis and give a few examples. I thought you would only use it if the ligand's name had di etc in it, for example 2dien ligands would be biethlyenetriaminetetraacetato?? HW Q11.31 sodium bisoxalato (diaqua) ferrate(III) Why did the solution put...
- Tue Nov 17, 2015 5:30 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Biological Importance
- Replies: 1
- Views: 463
Re: Biological Importance
the equation is basically showing the transport of oxygen by hemoglobin hemoglobin is made up of 4 proteins, each with a heme complex(tetradentate ligand + Fe in the middle). Oxygen molecule is transferred by binding to and then dissociating from the transition metal Fe, which is also bonded to the ...
- Fri Nov 13, 2015 2:50 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Given partial pressure, calculate equilibrium constant
- Replies: 2
- Views: 562
Re: Given partial pressure, calculate equilibrium constant
Thanks Nathan!
That's what I thought too... however, if converting kPa to Pa, shouldn't we times it by 1000 instead of dividing by 100?
That's what I thought too... however, if converting kPa to Pa, shouldn't we times it by 1000 instead of dividing by 100?
- Wed Nov 11, 2015 4:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Given partial pressure, calculate equilibrium constant
- Replies: 2
- Views: 562
Given partial pressure, calculate equilibrium constant
HW question 11.89 b
for reaction 2A <-> B + 2C
Partial pressure: A: 18kPa, B: 5kPa, C: 10kPa
Calculate the equilibrium constant
In the solution manual, K= ((5/100)(10/100)^2)/((18/100)^2)
Can you please explain why each partial pressure is divided by 100??
Thank you very much! :)
for reaction 2A <-> B + 2C
Partial pressure: A: 18kPa, B: 5kPa, C: 10kPa
Calculate the equilibrium constant
In the solution manual, K= ((5/100)(10/100)^2)/((18/100)^2)
Can you please explain why each partial pressure is divided by 100??
Thank you very much! :)
- Fri Nov 06, 2015 2:22 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Ionization energy based on valence- shell e-
- Replies: 3
- Views: 1050
Re: Ionization energy based on valence- shell e-
I think you meant 2e- in pi2px and 1e- in pi2py vs 1e- pi2px and 1e- in pi2px?? because in orbital has px, py and pz, so it can accept 3 pair of electron The atom with paired electron would have a lower higher ionization energy than the atom with unpaired electrons, because of e- repulsion. For exam...
- Mon Nov 02, 2015 10:03 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Ionization energy based on valence- shell e-
- Replies: 3
- Views: 1050
Ionization energy based on valence- shell e-
Homework Question 4.67 Base on their valence-shell electron configurations, which of the following species would you expect to have the lowest ionization energy? a) C2 + b) C2 c) C2 - The answer is C2- because its electron is lost from a higher energy level orbital, therefore more easily removed. So...
- Sun Nov 01, 2015 3:43 pm
- Forum: Hybridization
- Topic: What hybrid orbitals are involved
- Replies: 1
- Views: 319
What hybrid orbitals are involved
Quiz 2 preparation, Question 3
What hybrid orbitals are involved in the C-C sigma bonds and the C-H sigma bonds in benzene?
Can someone please explain what this question is asking??
How is this different from just asking for the hybridization of carbon, which is sp2?
What hybrid orbitals are involved in the C-C sigma bonds and the C-H sigma bonds in benzene?
Can someone please explain what this question is asking??
How is this different from just asking for the hybridization of carbon, which is sp2?
- Wed Oct 28, 2015 4:42 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond angles of atoms with lone pair electrons
- Replies: 1
- Views: 411
Bond angles of atoms with lone pair electrons
Just to clarify, Bent/ Angular (AX2E, AX2E2) has a bond angle of <120 degrees Trigonal Pyramidal (AX3E) has a bond angle of <109.5 degrees but a square planar(AX4E2) would have a bond angle of 90 degrees, because the lone pairs are symmetric and they cancel out?? What about Seesaw, T-shape and squar...
- Fri Oct 23, 2015 6:45 pm
- Forum: Lewis Structures
- Topic: Radicals
- Replies: 4
- Views: 487
Radicals
HW question 3.55: Which of the following species are radicals?? a) NO2- b)CH3 c)OH d)CH2O I understand that b is a radical, because C has an unpaired electron; however, the answer says that c) OH is also a radical.. Can someone please explain? Doesn't Oxygen have 6 paired electrons and 1 bonded to H...
- Thu Oct 15, 2015 11:07 am
- Forum: Trends in The Periodic Table
- Topic: Exceptions to trends in electron affinity
- Replies: 1
- Views: 1768
Exceptions to trends in electron affinity
Hi, I have a question about electron affinity. In general electron affinity increase across the period(except for nobel gases with affinity of 0) and decrease down the group; however, N has a negative electron affinity and Be and Mg also have <=0 electron affinities, and why does S have the greatest...
- Wed Oct 07, 2015 8:53 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric effect post-quiz 17-19 [ENDORSED]
- Replies: 6
- Views: 4357
Re: Photoelectric effect post-quiz 17-19 [ENDORSED]
a) E_{k}=\frac{1}{2}mv^{2}=\frac{1}{2}(9.10956*10^{-31} kg)(6.61*10^{5} \frac{m}{s})^{2}= 1.99*10^{-19} J b) work energy is the energy required to remove one electron, however, this is given in moles and we want it for one sodium atom, so we divide by Avogadro's number to energy get ...
- Sat Oct 03, 2015 5:14 pm
- Forum: DeBroglie Equation
- Topic: Given the energy, calculate the wavelength of y-rays
- Replies: 11
- Views: 1890
Re: Given the energy, calculate the wavelength of y-rays
Thank you very much!! I forgot that keV can be converted to joules... >_<
- Fri Oct 02, 2015 6:49 pm
- Forum: DeBroglie Equation
- Topic: Given the energy, calculate the wavelength of y-rays
- Replies: 11
- Views: 1890
Given the energy, calculate the wavelength of y-rays
Hw questions 1.23 The y-ray photons emitted by the nuclear decay of a technetium-99 atom used in radiopharmaceuticals have an energy of 140.511 keV. Calculate the wavelength of these y-rays. I have no idea how to start this question... help please !! :)