Search found 92 matches

by 704709603
Mon Mar 13, 2017 12:46 pm
Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
Topic: Green textbook 3.5-8
Replies: 1
Views: 279

Green textbook 3.5-8

In the Green textbook 3.5-8, how do we know where the chlorine or bromine atoms go since there are only two carbons? Thanks!
by 704709603
Mon Mar 06, 2017 8:38 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Final Winter 2015 #7BC
Replies: 1
Views: 264

Final Winter 2015 #7BC

For Final Winter 2015 #7BC, can someone explain why you solve this way?
thanks
by 704709603
Mon Mar 06, 2017 8:37 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Final Winter 2015 #6C
Replies: 1
Views: 241

Final Winter 2015 #6C

For Final Winter 2015 #6C, what is the reaction co-ordinate mean?
thanks
by 704709603
Mon Mar 06, 2017 8:35 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Final Winter 2014 #6 and 7
Replies: 1
Views: 257

Final Winter 2014 #6 and 7

For Final Winter 2014 #6 and 7, how would we have known to write out all these steps and what is the rate law for?
Thanks
by 704709603
Mon Mar 06, 2017 2:33 pm
Forum: *Electrophilic Addition
Topic: Final Winter 2014 #5B
Replies: 1
Views: 477

Final Winter 2014 #5B

Hi,
For Final Winter 2014 #5B, where does the H+ go after the Br is added to the CH3(CH2)OH? Does it go to the second CH2?
Thank you!
by 704709603
Mon Mar 06, 2017 11:14 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Practice Quiz 2 #11
Replies: 1
Views: 312

Practice Quiz 2 #11

Can some please show the work that you do to get the answer for #11 on the practice quiz 1 please?
by 704709603
Thu Mar 02, 2017 5:13 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Prep quiz 2 #11, 5
Replies: 2
Views: 386

Re: Prep quiz 2 #11, 5

Thank you! I tried that method for #11 and didn't get the right answer for some reason.
by 704709603
Thu Mar 02, 2017 5:11 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 3
Replies: 2
Views: 295

Quiz 3

Hi,
What will quiz 3 cover and can the answers to the practice quiz be posted please?
Thanks!
by 704709603
Mon Feb 27, 2017 10:28 am
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Prep quiz 2 #11, 5
Replies: 2
Views: 386

Prep quiz 2 #11, 5

Hi, how do you do 5 and 11 on prep quiz 2?
Thanks!
by 704709603
Sun Feb 26, 2017 7:48 pm
Forum: Administrative Questions and Class Announcements
Topic: Post-midterm review session
Replies: 1
Views: 282

Post-midterm review session

Will the extra post-midterm review session be videoed?
Thanks :)
by 704709603
Sat Feb 25, 2017 9:48 am
Forum: Administrative Questions and Class Announcements
Topic: O-Chem Black and white textbook
Replies: 3
Views: 339

O-Chem Black and white textbook

Hi,
Is the second book that we got with the course reader what we are meant to be reading through along with the O-chem material from now on?
Thanks!
by 704709603
Sat Feb 25, 2017 8:26 am
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2017
Replies: 160
Views: 15102

Re: Quiz 2 Winter 2017

Hi,
How do you do number 11?

Thanks!
by 704709603
Fri Feb 24, 2017 8:51 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: General Questions
Replies: 2
Views: 368

Re: General Questions

Great! That makes sense! Thank you!
by 704709603
Wed Feb 22, 2017 12:08 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: General Questions
Replies: 2
Views: 368

General Questions

How is order related to the mechanism? What is an example of when we would use the method from the course reader for multiple reactants that all change conc? What does it mean that a catalyst is saturated in a 0th order reaction?

Thanks!
by 704709603
Tue Feb 21, 2017 9:18 am
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2017
Replies: 160
Views: 15102

Re: Quiz 2 Winter 2017

For the pre-equilibrium approach: What if there are more than two steps in the mechanism? Also, how did you go from rate = k1 [CHBr3] ((k2[Br2])/k' 2) to rate = k [CHBr3][Br2]?
by 704709603
Mon Feb 20, 2017 9:17 am
Forum: General Rate Laws
Topic: 15.11
Replies: 1
Views: 290

15.11

N2O5 decomposes by a first-order run. Whats the initial rate of decamp when 3.45g is confined in 0.75L container and heated to 65C? k=5.2E-3.

I understand the answer, but was wondering if we should just ignore the temp?

Thanks!
by 704709603
Sun Feb 19, 2017 7:50 am
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2017
Replies: 160
Views: 15102

Re: Quiz 2 Winter 2017

Can some one explain question 1 and 5 please? Also, can we do calculations with any unit of time?
Thank you!
by 704709603
Sat Feb 18, 2017 9:20 am
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Pre-Equilibrium Help [ENDORSED]
Replies: 5
Views: 1407

Re: Pre-Equilibrium Help [ENDORSED]

What if there are more than two steps in the mechanism? Also, how did you go from rate = k1 [CHBr3] ((k2[Br2])/k' 2) to rate = k [CHBr3][Br2]?
by 704709603
Sat Feb 18, 2017 9:04 am
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2017
Replies: 160
Views: 15102

Re: Quiz 2 Winter 2017

Would it be possible to get the answers to the practice quiz please?
by 704709603
Mon Feb 13, 2017 8:18 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Increase in entropy
Replies: 2
Views: 261

Re: Increase in entropy

Thank you; that makes sense. Though why are the other wrong?
by 704709603
Mon Feb 13, 2017 7:57 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Increase in entropy
Replies: 2
Views: 261

Increase in entropy

Hi, Which of these process lead to an increase in entropy? a. pressure of 1mol oxygen is allowed to double isothermally b. carbon dioxide is allowed to expand isothermally to 10 times its original volume c. the temp of 1 mol of He is increased at constant pressure d. Nitrogen gas is compressed isoth...
by 704709603
Mon Feb 13, 2017 8:20 am
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: Hot Dog Demo
Replies: 1
Views: 315

Hot Dog Demo

Hi,
I couldn't see the set up of the demo, can someone explain what happened and why and what the take away was please?
Thank you!
by 704709603
Sun Feb 05, 2017 4:47 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: ion-selective electrodes
Replies: 1
Views: 277

ion-selective electrodes

Hi,
What would ion-selective electrodes for Na+ or K+ be used for, like measuring potassium in someone's blood?
Also, Eo imply equilibrium as well as standard conditions? Why is nerst eqn at 25C? I nerst just used for when concentrations are different and for electrolytic cells?
Thankyou!
by 704709603
Mon Jan 30, 2017 7:39 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs
Replies: 1
Views: 209

Gibbs

Can someone explain "if G is energy min then any decrease must be spontaneous" please?
Thanks!
by 704709603
Thu Jan 26, 2017 4:26 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Practice Quiz
Replies: 1
Views: 216

Practice Quiz

Hi,

If 2mol of an ideal gas at 300K and 3atm expands isothermally & reversibly from 6L to 18L and has a final pressure of 1.2 atm, what's w, q, and delta U.

Which eqn do we use since both volume and pressure change?
Thanks!
by 704709603
Wed Jan 25, 2017 3:47 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gibbs v internal
Replies: 1
Views: 252

Gibbs v internal

Hi,
What is the difference bw delta G and delta U? When calculating using the standard free energy of formation (the 3rd method) why is it specified that it is the "of formation" i.e. does it mean the free energy change when a molecule is formed (bonds made)?
Thank you!
by 704709603
Sat Jan 21, 2017 5:09 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Midterm 2013 winter Q3A
Replies: 1
Views: 267

Midterm 2013 winter Q3A

Blacksmith tempers a 1.45kg made of carbon steel to 314C and then dunks it into a large vat of room temp water 25C. Assuming all the heat of is transferred to the water such that the sword ends up at 25C, and the team does not heat past its measured boiling temp 100C, what is: the mass of the water ...
by 704709603
Sat Jan 21, 2017 4:29 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Midterm 2013 winter Q2A
Replies: 1
Views: 198

Midterm 2013 winter Q2A

Your friend asks for a glass of exactly 400g of water at 16C. You can get tap water at 25C from the faucet and ice at 0C from your freezer. How many grams of ice and how many grams of water must you combine to make his very specific request? So I understand most of the solution, but I don't really k...
by 704709603
Fri Jan 20, 2017 7:44 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: General questions [ENDORSED]
Replies: 4
Views: 666

General questions [ENDORSED]

Hi, So from the lecture: 1. What does the NA stand for in the equation W=2^(NA)? it's number of particles times avogadro's number? 2. Is Wg > Wl > Ws because of the greater movement of the gas molecules than those in the other states? 3. What constitutes the residual energy to be "low;" do...
by 704709603
Mon Jan 16, 2017 7:02 pm
Forum: Phase Changes & Related Calculations
Topic: heating curve
Replies: 3
Views: 341

Re: heating curve

Oh right! Thank you!
by 704709603
Mon Jan 16, 2017 6:24 pm
Forum: Phase Changes & Related Calculations
Topic: heating curve
Replies: 3
Views: 341

heating curve

hi,
from the course reader, can someone explain why the temperature doesn't change as heat is being added to the system?
Thank you!
by 704709603
Mon Jan 16, 2017 4:32 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: ch.8/#25
Replies: 2
Views: 292

ch.8/#25

Hi, #25 says: A constant-volume calorimeter was calibrated by carrying out a reaction known to release 3.50kJ of heat in 0.200L of solution in the calorimeter (q=-3.50kJ), resulting in a temperature change of 7.32C. In a subsequent experiment, 100.0mL of 0.200M HBr(aq) and 100.0mL of 0.200M KOH (aq)...
by 704709603
Mon Jan 16, 2017 4:18 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: ch.8/#21
Replies: 2
Views: 244

Re: ch.8/#21

#21: A piece of copper of mass 20.0g at 100C is placed in a vessel of negligible heat capacity but containing 50.7g of water at 22.0C. Calculate the final temperature of the water. Assume that no energy is lost to the surroundings.
by 704709603
Mon Jan 16, 2017 4:17 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Ch. 8/#19
Replies: 2
Views: 262

Re: Ch. 8/#19

Hi,
Sorry, here it is: a) calculate the heat that must be supplied to a 500.0g copper kettle containing 400.0g of water to raise its temperature from 22C to the boiling point of water, 100C. b) What percentage of the heat is used to raise the temperature of the water?
by 704709603
Sun Jan 15, 2017 7:52 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: ch.8/#23
Replies: 1
Views: 229

ch.8/#23

hi,
why don't we need the mass or the material of the calorimeter to find its heat capacity?
thank you!
by 704709603
Sun Jan 15, 2017 7:38 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: ch.8/#21
Replies: 2
Views: 244

ch.8/#21

Hi, in general, why is it that we do not always need to use moles for the calculations for enthalpy with heat capacity? also, for #21 why is it important to know that the vessel is of negligible heat capacity? also, is the final temperature of the copper equal to the initial temperature of the water...
by 704709603
Sun Jan 15, 2017 7:33 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Ch. 8/#19
Replies: 2
Views: 262

Ch. 8/#19

Hi, Why is it that we use the same delta T to find the enthalpy of the kettle as we used to find the enthalpy of the water? i.e. does the kettle also change temperature from 22 to 100 the same as the water? This seems odd to me since copper has a much lower heat capacity, though maybe that is the ke...
by 704709603
Tue Jan 10, 2017 2:03 pm
Forum: Phase Changes & Related Calculations
Topic: Reversible process
Replies: 3
Views: 332

Re: Reversible process

Oh ok! I think I understand mostly. Thank you for the video!
by 704709603
Mon Jan 09, 2017 7:56 pm
Forum: Phase Changes & Related Calculations
Topic: Reversible process
Replies: 3
Views: 332

Reversible process

Hi,
I don't understand the difference between a reversible vs. irreversible process.
Thanks!
by 704709603
Tue Nov 29, 2016 7:21 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: What does Kc tell us?
Replies: 5
Views: 3044

Re: What does Kc tell us?

I see thank you. So when Kc is small to get back to equilibrium, when a change in concentration has occurred, the production of products will be favored and visa versa?
by 704709603
Tue Nov 29, 2016 7:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: What does Kc tell us?
Replies: 5
Views: 3044

Re: What does Kc tell us?

Thank you! I mean more like the deeper meaning please.
by 704709603
Tue Nov 29, 2016 2:01 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: What does Kc tell us?
Replies: 5
Views: 3044

What does Kc tell us?

Hi, can someone explain what Kc tells us please?
Thank you!
by 704709603
Fri Nov 25, 2016 7:42 pm
Forum: Photoelectric Effect
Topic: Final exam 2013 Fall Q2A
Replies: 2
Views: 502

Re: Final exam 2013 Fall Q2A

Thank you!
by 704709603
Fri Nov 25, 2016 9:08 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: equilibrium constant
Replies: 3
Views: 392

equilibrium constant

Hi, Why is a side favored when a rxn is at equilibrium? It seems like neither side should be favored if a rxn has the same forward and reverse rates? I guess I'm wondering why we can have a run at equilibrium with different concentrations on both sides, or are the rates and concentrations not related?
by 704709603
Thu Nov 24, 2016 7:34 pm
Forum: Photoelectric Effect
Topic: Final exam 2013 Fall Q2A
Replies: 2
Views: 502

Final exam 2013 Fall Q2A

Hi, Q: e- ejected from sodium. if wavelength of ejected e- is 1.1 nm, what was the frequency of the incident light? work fxn for sodium =150.6kJ/mol Why do we need to find the velocity of the ejected electron first? Why can't we use E=h(nu) to find the Ek? Is it because the electron comes out at a c...
by 704709603
Tue Nov 22, 2016 2:12 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: #electrons
Replies: 1
Views: 294

#electrons

Hi
Why can there only be 2 electrons in an atom if n=5, l=3, ml=-1 and also if n=2, l is 1 and ml is 0?

How do you show that momentum is proportional to the number of cycles per meter?

Thank you!
by 704709603
Tue Nov 15, 2016 7:48 pm
Forum: Naming
Topic: Chem prep quiz 3 fall 2014 [ENDORSED]
Replies: 2
Views: 415

Re: Chem prep quiz 3 fall 2014 [ENDORSED]

Ahh Yes! Thank you so much! :)
by 704709603
Tue Nov 15, 2016 10:23 am
Forum: Naming
Topic: Chem prep quiz 3 fall 2014 [ENDORSED]
Replies: 2
Views: 415

Chem prep quiz 3 fall 2014 [ENDORSED]

Why is [Co(en)2(CN)Cl]Cl not named chlorocyanobisethylenediamminecobalt(III)chlorine but has chloride as the counter ion?
Thanks!
by 704709603
Thu Nov 10, 2016 11:38 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Quiz 3 prep [ENDORSED]
Replies: 6
Views: 756

Re: Quiz 3 prep [ENDORSED]

Oh, ok thank you!
by 704709603
Tue Nov 08, 2016 4:09 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Quiz 3 prep [ENDORSED]
Replies: 6
Views: 756

Quiz 3 prep [ENDORSED]

For Quiz 3 prep are we meant to include the ethylenes attached to the ammines when we draw [Cu(dien)2]^2+?
by 704709603
Tue Nov 08, 2016 4:08 pm
Forum: Lewis Structures
Topic: Quiz 2 prep
Replies: 2
Views: 417

Quiz 2 prep

What was the answer for quiz prep 2 #3: lewis structure for S2O3^2- that follows the octet rule?
by 704709603
Tue Nov 08, 2016 4:04 pm
Forum: Lewis Structures
Topic: Fall Quiz 2 2014
Replies: 1
Views: 357

Fall Quiz 2 2014

4. Knowing that carbon has a valence of four in nearly all its compounds and can form chains and rings of C atoms, draw two possible chain structures for C3H4.
by 704709603
Tue Nov 08, 2016 3:58 pm
Forum: Naming
Topic: Fall Quiz 3 2014
Replies: 1
Views: 221

Fall Quiz 3 2014

2. Name Na[Co(NH3)3Cl3]
I wrote triamminetricholorocobalt(II)sodium.
Why is there meant to be an -ate on the cobalt?
by 704709603
Tue Nov 08, 2016 3:49 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Coordination number
Replies: 1
Views: 232

Coordination number

How you do find the coordination number from a given formula of a coordination complex? Thanks!
by 704709603
Tue Nov 08, 2016 3:46 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Astrixes on ligans in table in course reader
Replies: 2
Views: 350

Astrixes on ligans in table in course reader

Hi,
Why are there astrixes on some of the ligands in the table in the course reader? Thank you!
by 704709603
Mon Nov 07, 2016 10:17 am
Forum: Naming
Topic: Naming
Replies: 2
Views: 285

Re: Naming

Why are there astrixes on come of the names in course reader? I assume that they denote some special property but I'm not sure what.
Thanks!
by 704709603
Mon Nov 07, 2016 10:15 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Shape of coordination compound
Replies: 3
Views: 766

Re: Shape of coordination compound

Is shape of coordination compounds something that we should be comfortable with?
Thanks!
by 704709603
Tue Nov 01, 2016 2:46 pm
Forum: Hybridization
Topic: Practice midterm question
Replies: 1
Views: 275

Practice midterm question

course reader p.188 Q6A: Can someone explain parts 1-3 please? I don't understand how we know how many hydrogen atoms are on each carbon without prior knowledge about proline. Thank you!
by 704709603
Tue Nov 01, 2016 10:42 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: What is MO theory for? [ENDORSED]
Replies: 20
Views: 6689

Re: What is MO theory for? [ENDORSED]

Wow, very interesting. Thank you!
by 704709603
Tue Nov 01, 2016 10:20 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: What is MO theory for? [ENDORSED]
Replies: 20
Views: 6689

What is MO theory for? [ENDORSED]

So, MO theory allows us to find the bonding order and the magnetic properties but why does knowing those things help us i.e. what are they for?
by 704709603
Mon Oct 31, 2016 6:44 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Molecular Orbital theory
Replies: 5
Views: 400

Re: Molecular Orbital theory

So, MO theory allows us to find the bonding order and the magnetic properties but why does knowing those things help us i.e. what are they for?
by 704709603
Fri Oct 28, 2016 12:29 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 1
Replies: 2
Views: 393

Midterm 1

Hi,
Up to what lecture does the midterm 1 cover?
Thank you!
by 704709603
Mon Oct 24, 2016 2:05 pm
Forum: Ionic & Covalent Bonds
Topic: CN-
Replies: 4
Views: 381

Re: CN-

Yes, was referring to the bond. Thank you!
by 704709603
Mon Oct 24, 2016 10:46 am
Forum: Ionic & Covalent Bonds
Topic: CN-
Replies: 4
Views: 381

CN-

Hi, is CN- not very strong since it is ionic?
Thanks!
by 704709603
Thu Oct 20, 2016 5:54 pm
Forum: Lewis Structures
Topic: Forming double bonds [ENDORSED]
Replies: 1
Views: 213

Forming double bonds [ENDORSED]

Hi,
Why do we remove the two e- from a lone pair to create a double bond when only 1 e- is actually needed to form a covalent bond? Or is my thinking incorrect?
Thanks!
by 704709603
Thu Oct 20, 2016 8:18 am
Forum: Ionic & Covalent Bonds
Topic: Ch 3 #9,11 [ENDORSED]
Replies: 5
Views: 501

Re: Ch 3 #9,11 [ENDORSED]

Oh, I understand! Thank you!
by 704709603
Wed Oct 19, 2016 9:19 am
Forum: Trends in The Periodic Table
Topic: Electron affinity
Replies: 5
Views: 550

Electron affinity

Hi,
why is the electron affinity of Br so high when it usually has a charge of -1? Wouldn't that mean that it does not want another e-?
Thank you!
by 704709603
Tue Oct 18, 2016 7:54 am
Forum: Ionic & Covalent Bonds
Topic: Ch 3 #9,11 [ENDORSED]
Replies: 5
Views: 501

Re: Ch 3 #9,11 [ENDORSED]

With a +2 charge shouldn't we subtract 2 from 25?
by 704709603
Mon Oct 17, 2016 11:05 am
Forum: Ionic & Covalent Bonds
Topic: Ch 3 #9,11 [ENDORSED]
Replies: 5
Views: 501

Ch 3 #9,11 [ENDORSED]

Hi,
Can anyone explain 3.9 and 3.11 please?

Thank you!
by 704709603
Fri Oct 14, 2016 12:13 pm
Forum: Trends in The Periodic Table
Topic: Ch 2. #67,81. 47,39,29
Replies: 1
Views: 221

Ch 2. #67,81. 47,39,29

Hi,
Can someone explain b in 67 and the part about electron repulsion in 81 please? And then 47,39,29 please :)
Thank you!
by 704709603
Sat Oct 08, 2016 7:23 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Homework Problems #11 and #15 [ENDORSED]
Replies: 4
Views: 546

Re: Homework Problems #11 and #15 [ENDORSED]

Hi,
How do you solve 15 without the Rydberg equation?
Thank you!
by 704709603
Fri Oct 07, 2016 4:24 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Post Module Heisenberg #11 [ENDORSED]
Replies: 4
Views: 564

Re: Post Module Heisenberg #11 [ENDORSED]

How do you find the uncertainty in the kinetic energy per mole?
by 704709603
Thu Oct 06, 2016 3:24 pm
Forum: Empirical & Molecular Formulas
Topic: Writing chem eqns
Replies: 1
Views: 258

Writing chem eqns

Hi,
Do I need to memorize the charged of the transition metals so that I can know how to write their names?
Thank you!
by 704709603
Mon Oct 03, 2016 9:04 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Online module assessment solutions
Replies: 2
Views: 381

Online module assessment solutions

Hi,
Is there somewhere we can access the solutions to the online module assessments? No worries if not, I'll go to office hours.

Thank you!
by 704709603
Wed Sep 28, 2016 11:30 am
Forum: Photoelectric Effect
Topic: Threshold energy question from pre assessment module
Replies: 1
Views: 246

Threshold energy question from pre assessment module

When the energy per photon is equal to the energy required to remove an e-, is that called the threshold energy? Thank you :)
by 704709603
Wed Sep 28, 2016 9:13 am
Forum: Properties of Light
Topic: Balmer, Lyman, and Paschen series HW question 1.11
Replies: 4
Views: 2020

Re: Balmer, Lyman, and Paschen series HW question 1.11

I'm also confused about the series and atomic spectra. :/
by 704709603
Wed Sep 28, 2016 8:45 am
Forum: Photoelectric Effect
Topic: Photoelectric effect pre-module assessment #17-19
Replies: 8
Views: 753

Re: Photoelectric effect pre-module assessment #17-19

How did you find the mass of the sodium e-?
by 704709603
Tue Sep 27, 2016 8:37 pm
Forum: Photoelectric Effect
Topic: Intensity
Replies: 5
Views: 564

Re: Intensity

In lecture, I believe Lavelle said that intensity is a higher amplitude.
by 704709603
Tue Sep 27, 2016 12:42 pm
Forum: Properties of Light
Topic: EM radiation and Colors
Replies: 2
Views: 286

Re: EM radiation and Colors

Thank you very much!
by 704709603
Tue Sep 27, 2016 12:41 pm
Forum: Photoelectric Effect
Topic: Intensity
Replies: 5
Views: 564

Re: Intensity

Thank you very much!
by 704709603
Tue Sep 27, 2016 12:41 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Post-Module Assessment #22-23
Replies: 5
Views: 1888

Re: Photoelectric Effect Post-Module Assessment #22-23

Thank you very much! I'm pretty sure that the 1.02x10^-18J is actually the E of the photon so we then need to subtract from it the threshold energy from the previous problem to get 3.03x10^19J. Right?
by 704709603
Mon Sep 26, 2016 7:21 pm
Forum: Photoelectric Effect
Topic: Intensity
Replies: 5
Views: 564

Intensity

Hi :)

Can someone explain what this statement in the course reader means please?: "If light had only wave properties them increasing the intensity should eject e-"

Thank you!
by 704709603
Mon Sep 26, 2016 7:19 pm
Forum: Properties of Light
Topic: EM radiation and Colors
Replies: 2
Views: 286

EM radiation and Colors

Hi :) Can someone explain why EM radiation is seen as light please? I know that when electrons are excited they give off photons when they are move to a different energy level in a material's atoms, but literally why are photons seen as light? Also, when stage lights are filtered through a green, re...
by 704709603
Mon Sep 26, 2016 4:28 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Post-Module Assessment #22-23
Replies: 5
Views: 1888

Photoelectric Effect Post-Module Assessment #22-23

Hi :) Can someone explain what the answer to the question is and the reasoning behind it please? 22. Molybdenum metal must absorb radiation with a minimum frequency of 1.09 x 1015 s-1 before it can emit an electron from its surface. Answer the following two questions. A. What is the minimum energy n...
by 704709603
Mon Sep 26, 2016 4:22 pm
Forum: Photoelectric Effect
Topic: Photoelectric effect pre-module assessment #17-19
Replies: 8
Views: 753

Photoelectric effect pre-module assessment #17-19

Hi :) Can someone explain what the answer to the question is and the reasoning behind it please? Light hits a sodium metal surface and the velocity of the ejected electron is 6.61x10^5 m.s^-1. The work function for sodium is 150.6 kJ.mol^-1. Answer the following 3 questions. A. What is the kinetic e...
by 704709603
Mon Sep 26, 2016 4:15 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Balancing Chemistry Equations Pre-module Assessment Question #6
Replies: 2
Views: 502

Balancing Chemistry Equations Pre-module Assessment Question #6

Hi :) Can someone explain what the answer to the question is and the reasoning behind it please? During a summer camping weekend 4 moles of butane (C4H10) gas were used for cooking. Choose the right balanced equation for the combustion of 4 moles of butane gas. What's the net number of moles of gas ...

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