Search found 70 matches

by Racquel Fox 2I
Mon Jan 25, 2021 12:20 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Textbook 4E.7 part b
Replies: 3
Views: 10

Textbook 4E.7 part b

Use the data in Tables 4E.2 and 4E.3 to estimate the reaction enthalpy for b) CH3CHCH2 (g) + H2O --> CH3CH(OH)CH3 (g) How do you calculate the bond enthalpy for H2O? The tables don't give it, and the only bond enthalpy they give is O-H, which I don't think you can just multiply by two because that w...
by Racquel Fox 2I
Sat Jan 23, 2021 5:03 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Textbook 4D.21 part c
Replies: 1
Views: 12

Textbook 4D.21 part c

4D.21) c) Use standard enthalpies of formation from Appendix 2A to calculate the standard reaction enthalpy for each of the following reactions: H2S (aq) + 2KOH (aq) --> K2S (aq) + 2H2O (l) I got -38.72 kJ as the answer, but the solutions says its +15.28 kJ. I got the other parts right, so I thought...
by Racquel Fox 2I
Sat Jan 23, 2021 12:43 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Textbook 4D.13
Replies: 1
Views: 12

Textbook 4D.13

4D.13) Barium metal is produced by the reaction of aluminum metal with barium oxide. From the standard reaction enthalpies, 2Ba(s) + O2(g) --> 2BaO (s) deltaH = -1107 kJ 2Al(s) + 3/2O2(g) --> Al2O3(s) deltaH=1676 kJ calculate the reaction enthalpy for the production of metallic barium in the reactio...
by Racquel Fox 2I
Mon Jan 18, 2021 12:44 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Textbook 6D.15 part b
Replies: 1
Views: 14

Textbook 6D.15 part b

Calculate the pH of (b) 0.055 M AlCl3(aq).

Where do you find the Ka/Kb value for this part? I can't find it in the 6C.1 and 6C.2 tables?
by Racquel Fox 2I
Sun Jan 17, 2021 7:33 pm
Forum: Student Social/Study Group
Topic: Study Strategies
Replies: 31
Views: 50

Re: Study Strategies

I struggled a lot in 14A, but found when I read over the information in the textbook for the next lecture before it occurred, I was able to get a better understanding of the material when doing the textbook problems. Also, definitely go to the UA workshops! They are so helpful and give you extra pra...
by Racquel Fox 2I
Sun Jan 17, 2021 6:47 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Sapling Week 2 #2
Replies: 4
Views: 22

Sapling Week 2 #2

At first when I did this problem, I made the assumption that you could change the 0.176-x in the denominator of the Ka equation to just 0.176 and got the answer wrong. When attempting it for the second time, I kept it as 0.176-x and got it right, but I'm a little confused on when you can assume that...
by Racquel Fox 2I
Sun Jan 17, 2021 1:14 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Q > K, Q< K
Replies: 25
Views: 75

Re: Q > K, Q< K

When Q>K, the reaction shifts towards the reactants, and when Q<K, the reaction shifts toward the products. There's a tip where if you write the K before the Q, the arrow points towards the direction of the shift: K<Q, shift toward reactants; K>Q, shift toward products.
by Racquel Fox 2I
Sun Jan 17, 2021 1:12 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: sapling week 1/2 #2
Replies: 3
Views: 21

Re: sapling week 1/2 #2

Where exactly are you having trouble? Make sure you are setting up the ICE box correctly, finding all of the equilibrium concentrations, and then solving for K.
by Racquel Fox 2I
Fri Jan 15, 2021 1:01 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: 6D.5 part d
Replies: 3
Views: 32

6D.5 part d

6D.5) Calculate the pH, pOH, and percentage protonation of solute in each of the following aqueous solutions: (d) 0.0073 M codeine, given that the pKa of its conjugate acid is 8.21. I don't really know how to go about starting this problem since the formula for codeine isn't given. If anyone could t...
by Racquel Fox 2I
Sun Jan 10, 2021 5:43 pm
Forum: Student Social/Study Group
Topic: Study Habits
Replies: 94
Views: 259

Re: Study Habits

I struggled with studying for midterms for 14A, but I did much better on the final when I started learning the material before it appeared in lecture, so that lecture was more of a review for me to get a better understanding. Also, do a LOT of practice problems!
by Racquel Fox 2I
Sat Jan 09, 2021 3:53 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Impacts of Increasing Pressure
Replies: 4
Views: 13

Re: Impacts of Increasing Pressure

I'm pretty sure that even if the problem doesn't mention volume, the volume change is inferred because you can't have an increase in pressure and have everything else stay the same.
by Racquel Fox 2I
Thu Jan 07, 2021 5:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Partial pressure vs concentration
Replies: 6
Views: 25

Re: Partial pressure vs concentration

I'm pretty sure you would generally use the partial pressure for gases, but you are able to convert pressure to concentration and vice versa by the equation Lavelle mentioned in class: P = nRT/V where n/V = concentration
by Racquel Fox 2I
Thu Jan 07, 2021 5:04 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sapling #5
Replies: 4
Views: 32

Re: Sapling #5

The way I did this problem was by looking at the reactants and products given in the equation, and then seeing which other chemical equations contained them. For this problem, the two equations used are I2 <--> 2I and N2 + 3H2 <--> 2NH3. There are a couple rules regarding this type of problem worth ...
by Racquel Fox 2I
Tue Jan 05, 2021 3:00 pm
Forum: Student Social/Study Group
Topic: Learning Sessions
Replies: 24
Views: 121

Re: Learning Sessions

I think I understood the material best when I went to 2 during a week, but it completely depends on your schedule, and if that doesn't work for you definitely try to attend at least one.
by Racquel Fox 2I
Sat Dec 12, 2020 3:12 pm
Forum: Amphoteric Compounds
Topic: Glycine Amphoteric
Replies: 3
Views: 27

Re: Glycine Amphoteric

Sana Nagori 2J wrote:I think because if oxygen donated a pair it would end up with a positive formal charge and oxygens do not want that.


Why would N want a +1 charge thought?
by Racquel Fox 2I
Sat Dec 12, 2020 2:50 pm
Forum: Amphoteric Compounds
Topic: Glycine Amphoteric
Replies: 3
Views: 27

Glycine Amphoteric

For the lewis structure of glycine, (NH2CH2COOH), you get N with a lone pair, and two O with two lone pairs. The lone pair on the N contributes to the amphoteric character, but why wouldn't the lone pairs on the O atoms? I'm not sure if that makes sense, but I'm just a little confused why the lone p...
by Racquel Fox 2I
Sat Dec 12, 2020 12:31 am
Forum: Lewis Structures
Topic: Exception to Octet rule (Cl)
Replies: 6
Views: 27

Re: Exception to Octet rule (Cl)

Cl can have an expanded octet because its in the 3rd period on the periodic table, and the 3p elements and lower can have an expanded octet. I believe for this problem Cl would be the central atom for the sake of symmetry where it could have two O on either side that are double bonded, and a lone pa...
by Racquel Fox 2I
Fri Dec 11, 2020 1:44 pm
Forum: Biological Examples
Topic: Hemoglobin Information for Final
Replies: 3
Views: 80

Re: Hemoglobin Information for Final

Kailani_Dial_3G wrote:Heme.png

This would be the octahedral shape as you can see it has the attachments above and below the heme

If you were to remove the Oxygen and the histadine that it attached to the bottom then it would be square planar


Thank you that's really helpful!
by Racquel Fox 2I
Fri Dec 11, 2020 1:19 pm
Forum: Biological Examples
Topic: Hemoglobin Information for Final
Replies: 3
Views: 80

Hemoglobin Information for Final

I was doing the Marshmallow worksheet and was confused on the answer for the expected geometry for the compound for the heme complex (Q 20). The answers say that the shape is tetrahedral or square planar, but how can it be both of those if square planar is an octahedral electron geometry? I'm not su...
by Racquel Fox 2I
Wed Dec 09, 2020 10:48 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 2
Views: 28

Rydberg Equation

I know the Rydberg equation on the equation sheet is v=R[1/(n1^2) - 1/(n2^2)], but in one of the review sessions yesterday the equation En=-(hR)/n^2 was brought up. Can you derive the first equation from the second one, and if we had a question on the final asking about energy levels, which equation...
by Racquel Fox 2I
Tue Dec 08, 2020 10:14 pm
Forum: Conjugate Acids & Bases
Topic: Acid Base Equilibrium
Replies: 1
Views: 16

Acid Base Equilibrium

Predict the product of the following acid-base reactions, and also predict whether the equilibrium lies to the left or to the right of the equation:
HCO3 - (aq) + F - (aq)

I got that the products would be HF and CO3 2-, but I'm a little confused on how you know where the equilibrium lies?
by Racquel Fox 2I
Tue Dec 08, 2020 8:40 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Shape of Coordination Compounds
Replies: 1
Views: 17

Shape of Coordination Compounds

Is the only way to find the shape of a coordination compound to draw out the Lewis structure, or is there another way?
by Racquel Fox 2I
Mon Dec 07, 2020 9:50 pm
Forum: Biological Examples
Topic: Cisplatin
Replies: 2
Views: 56

Cisplatin

I've seen a few problems in workshops that ask specific questions about cisplatin, and I don't fully understand them and want to go over it more. Does anyone know where in the textbook it explains?
by Racquel Fox 2I
Sun Dec 06, 2020 6:54 pm
Forum: Polyprotic Acids & Bases
Topic: Textbook 6C.19
Replies: 7
Views: 61

Re: Textbook 6C.19

I'm a little confused on the answer for part a) and part c). Part a) is comparing HF and HCl and part c) is comparing HBrO2 and HClO2. Why would HCl be stronger than HF, and HClO2 stronger than HBrO2? What is the periodic trend going on? Remember in the last lecture where Dr. Lavelle said that the ...
by Racquel Fox 2I
Sun Dec 06, 2020 6:20 pm
Forum: Polyprotic Acids & Bases
Topic: Textbook 6C.19
Replies: 7
Views: 61

Textbook 6C.19

I'm a little confused on the answer for part a) and part c). Part a) is comparing HF and HCl and part c) is comparing HBrO2 and HClO2. Why would HCl be stronger than HF, and HClO2 stronger than HBrO2? What is the periodic trend going on?
by Racquel Fox 2I
Sun Dec 06, 2020 12:45 pm
Forum: Student Social/Study Group
Topic: Studying for Final Exam
Replies: 57
Views: 368

Re: Studying for Final Exam

I'm going to go over textbook problems on the unit outlines, starting with newer material and working backward. I'm also definitely going to review sessions with UAs this week. If it helps you, try and make a schedule to plan out how you will be studying each day for the final. It makes your studyin...
by Racquel Fox 2I
Sun Dec 06, 2020 12:43 pm
Forum: Administrative Questions and Class Announcements
Topic: Partial Credit on the Final
Replies: 6
Views: 67

Partial Credit on the Final

Does anyone know if any of the questions on the final exam will offer partial credit? Or will it be more like the second midterm where no partial credit was offered?
by Racquel Fox 2I
Thu Dec 03, 2020 10:24 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelates and Polydentates
Replies: 2
Views: 17

Chelates and Polydentates

Are all polydentates automatically considered chelates?
by Racquel Fox 2I
Thu Dec 03, 2020 10:41 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Sapling Homework #5
Replies: 2
Views: 38

Sapling Homework #5

I'm a little confused on how to go about finding coordination numbers for this question. At first I thought it had
something to do with the oxidation state, so I don't really know how to start if someone could
let me know a good starting point.
by Racquel Fox 2I
Wed Dec 02, 2020 3:47 pm
Forum: Naming
Topic: Oxidation State
Replies: 4
Views: 38

Oxidation State

Are oxidation states just the charge on the atoms?
by Racquel Fox 2I
Sun Nov 29, 2020 3:52 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent
Replies: 9
Views: 62

Re: Bent

Yeah I'm pretty sure it is.
by Racquel Fox 2I
Sat Nov 28, 2020 2:26 pm
Forum: Student Social/Study Group
Topic: Midterm Exam Questions
Replies: 16
Views: 149

Re: Midterm Exam Questions

Definitely email your TA to schedule a meeting to go over your midterm. I just went over my midterm with my TA and it clarified a lot for me.
by Racquel Fox 2I
Sat Nov 28, 2020 2:25 pm
Forum: Student Social/Study Group
Topic: Final Study
Replies: 32
Views: 199

Re: Final Study

I would try and do more of the textbook problems, and definitely find some of the worksheets from past workshops. If you search chemistry community, you can usually find some :)
by Racquel Fox 2I
Sat Nov 28, 2020 2:21 pm
Forum: Student Social/Study Group
Topic: Studying From Home
Replies: 91
Views: 496

Re: Studying From Home

I feel the same way, I always went to the library and used to never be able to study at home. I just try to switch up my location in my house a bit so I'm never stuck in one place for too long. I like to listen to music while I study because it helps me get into more of a rhythm while studying. I al...
by Racquel Fox 2I
Thu Nov 26, 2020 3:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Chart
Replies: 18
Views: 104

VSEPR Chart

Does anyone know if we will get a VSEPR chart for the final, or do we have to memorize all of the molecular shapes?
by Racquel Fox 2I
Sun Nov 22, 2020 10:31 pm
Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
Topic: Polarizablity
Replies: 10
Views: 82

Re: Polarizablity

Polarizability is the tendency of an anion to get distorted by a cation and increases when the size of the anion increases.
by Racquel Fox 2I
Sun Nov 22, 2020 4:49 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Plausible Formal Charges
Replies: 6
Views: 29

Re: Plausible Formal Charges

The most stable Lewis structure is the structure with the lowest amount of charge, if not a charge of zero.
by Racquel Fox 2I
Wed Nov 18, 2020 10:17 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: d vs s orbitals
Replies: 7
Views: 98

Re: d vs s orbitals

Jacquelyn Challis 1H wrote:Just to clarify, when writing electron configurations, would you write 3d or 4s first? I've seen it done both ways and I'm getting confused.


In order to fill them in the right order, you can write 4s first, but proper electron configuration is to put it back to 3d, 4s.
by Racquel Fox 2I
Tue Nov 17, 2020 3:39 pm
Forum: Quantum Numbers and The H-Atom
Topic: Cr+ Ground State Electron Configuration
Replies: 2
Views: 29

Cr+ Ground State Electron Configuration

Write the ground-state electron configuration for Cr+ and give the first two quantum numbers for the last electron.
Answer: Cr: [Ar]4s13d5, Cr+: [Ar] 3d5

Why would the 4s orbital only have 1 electron?
by Racquel Fox 2I
Tue Nov 17, 2020 12:29 pm
Forum: Quantum Numbers and The H-Atom
Topic: Quantum Number Practice
Replies: 3
Views: 48

Quantum Number Practice

Does anyone have any good extra quantum number practice? I did all of the questions in the textbook and the sapling homework but I just want to make sure I'm really prepared for MT2.
by Racquel Fox 2I
Sun Nov 15, 2020 4:43 pm
Forum: Octet Exceptions
Topic: Textbook 2C.1
Replies: 5
Views: 50

Re: Textbook 2C.1

SebastianCastellanos2L wrote:I ran into the same problem and I also think that the answer key in the online textbook is likely mistaken. I have noticed that its missing answers for certain questions and the explanation from the physical one makes the most sense.


Thank you! I'm glad I'm not the only one haha
by Racquel Fox 2I
Sat Nov 14, 2020 1:42 pm
Forum: Octet Exceptions
Topic: Textbook 2C.1
Replies: 5
Views: 50

Textbook 2C.1

Which of the following species are radicals? a) NO2-; b) CH3; c) OH; d) CH2O I'm a little confused on part A of 2C.1. I counted the number of valence electrons, and with the added electron from the negative charge, I got 18 ve-, but in the answer key that is one of the radicals. What am I doing wron...
by Racquel Fox 2I
Sat Nov 14, 2020 1:22 pm
Forum: Student Social/Study Group
Topic: Midterm 2
Replies: 22
Views: 135

Re: Midterm 2

I'm going to focus more on the textbook problems. I think I'm going to do all of the odd questions in the sections, and then when I have a good grip on them I'm going to go back and do the evens. Also, I'm going to spend more time really understanding the conceptual ideas because that's where I had ...
by Racquel Fox 2I
Sat Nov 14, 2020 1:20 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Number of Resonance Structures
Replies: 7
Views: 82

Re: Number of Resonance Structures

I know that resonance structures are any molecule with 2 or more Lewis dot structures, but I'm pretty sure we wouldn't get a really hard, time-extensive one on the midterm, so I wouldn't worry too much about that :)
by Racquel Fox 2I
Wed Nov 11, 2020 2:55 pm
Forum: Ionic & Covalent Bonds
Topic: Textbook: 2a.3
Replies: 2
Views: 31

Textbook: 2a.3

I just wanted to check and see if I was setting up electron configurations right for 2a.3. 2a.3)a) S^2- : 1s^2 2s^2 2p^6 3s^2 3p^6 or Ar 2a.3)b) As^3+ : 1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 or Ar 3d^10 4s^2 2a.3)d) Ge^2+ : 1s^2 2s^2 2p^6 3s^2 3p^6 3d^10 4s^2 or Ar 3d^10 4s^2 Also, I'm slightly confus...
by Racquel Fox 2I
Fri Nov 06, 2020 8:15 pm
Forum: Lewis Structures
Topic: Electron Configuration; Aufbau Principle
Replies: 5
Views: 56

Re: Electron Configuration; Aufbau Principle

Thank you so much! I was having a lot of trouble understanding it so it's really nice to have that help :)
by Racquel Fox 2I
Fri Nov 06, 2020 8:13 pm
Forum: Properties of Light
Topic: Photoelectric Effect
Replies: 14
Views: 138

Re: Photoelectric Effect

Yes, I'm pretty sure that the excess energy is the same as the kinetic energy because the kinetic energy is the excess energy that is produced when the energy of the photon is greater than the work function.
by Racquel Fox 2I
Fri Nov 06, 2020 8:07 pm
Forum: Student Social/Study Group
Topic: Blind sided by Midterm 1 memorization questions, How to study for memorization questions
Replies: 11
Views: 118

Re: Blind sided by Midterm 1 memorization questions, How to study for memorization questions

I feel the same; I feel like I studied really hard to try and get all of the calculations down, but skimmed over the conceptual parts and thought I would be able to reason them out. I think that the best thing we can do going forward is put a little more time into truly understanding the conceptual ...
by Racquel Fox 2I
Fri Nov 06, 2020 8:03 pm
Forum: Ionic & Covalent Bonds
Topic: Formal Charge Equation
Replies: 10
Views: 52

Formal Charge Equation

I know that the equation for the formal charge for Lewis Dot Structure is FC = # valence electrons - the number of dots and lines, but I'm getting a little confused on the concept behind the bond lines. I know that they are bonded electrons, but why would one bond line count as one when it is two el...
by Racquel Fox 2I
Wed Oct 28, 2020 1:01 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post-Module Assessment #28
Replies: 1
Views: 39

Atomic Spectra Post-Module Assessment #28

The meter was defined in 1963 as 1,650,763.73 wavelengths of radiation emitted by krypton-86 (it has since been redefined). What is the wavelength of this krypton-86 radiation? To what region of the electromagnetic spectrum does this wavelength correspond (i.e. infrared, ultraviolet, x-ray, etc.)? W...
by Racquel Fox 2I
Tue Oct 27, 2020 10:26 pm
Forum: Einstein Equation
Topic: Work Function and Energy of Photons
Replies: 4
Views: 49

Work Function and Energy of Photons

In some practice problems I've been doing I noticed that E=hv is equal to the work function. How do you know when you are supposed to set them equal to each other?
by Racquel Fox 2I
Tue Oct 27, 2020 3:30 pm
Forum: Properties of Light
Topic: Energy Equations Confusion
Replies: 6
Views: 57

Re: Energy Equations Confusion

In order to solve this you need to know the work function of the substance the incident light is ejecting the electron from. Once you know this you can use the photoelectric equation (kinetic energy of electron) = (energy of photon) - (work function). Plug in the kinetic energy of the electron and ...
by Racquel Fox 2I
Tue Oct 27, 2020 3:27 pm
Forum: Properties of Light
Topic: Energy Equations Confusion
Replies: 6
Views: 57

Re: Energy Equations Confusion

Minh-Thy Vo 3E wrote:To find the energy you would use Ek=1/2mv^2 because it is asking for kinetic energy.
For the wavelength you would use the de Broglie equation wavelength= h/p using the mass of an electron and the velocity given.


I thought that the kinetic energy was given? Am I wrong about that?
by Racquel Fox 2I
Tue Oct 27, 2020 3:23 pm
Forum: Properties of Light
Topic: Energy Equations Confusion
Replies: 6
Views: 57

Energy Equations Confusion

A shorter wavelength light source is used resulting in ejected electrons with a kinetic energy of 4.200 * 10^-19 J
What is the energy of the incident light?
What is the wavelength of this incident light?

I'm a little confused on how to start this equation if anyone could offer some insight.
by Racquel Fox 2I
Mon Oct 26, 2020 10:39 pm
Forum: Properties of Light
Topic: 1B. 5 Textbook problem
Replies: 1
Views: 33

Re: 1B. 5 Textbook problem

1 keV uses the prefix "kilo", so you would need to convert the keV to eV by multiplying by 10^3 eV and then converting to J.
by Racquel Fox 2I
Mon Oct 26, 2020 10:37 pm
Forum: Properties of Electrons
Topic: Sapling Homework #14
Replies: 5
Views: 78

Re: Sapling Homework #14

I'm pretty sure n2 = 7, and with that you would get the v = R((1/n1^2) - (1/n2^2)) to be 3.29*10^15 x ((1/4)-(1/49)). Why does n2=7? Sorry, I just looked back at your post and realized you said your n2=6. I'm not sure if we have different questions, but my #14 on Sapling states: Calculate the wavel...
by Racquel Fox 2I
Mon Oct 26, 2020 10:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Locked out of textbook
Replies: 1
Views: 27

Re: Locked out of textbook

I would email your TA to figure it out, especially if you've already redeemed your access code.
by Racquel Fox 2I
Mon Oct 26, 2020 10:26 pm
Forum: General Science Questions
Topic: help with work function hw question
Replies: 2
Views: 45

Re: help with work function hw question

For the first part, I think you would use the Ek = hv - phi equation and solve for phi. So you would basically get
phi = hv - Ek --> (6.626*10^-34)(1.15 s^-1) - (3.80*10^-19 J)
by Racquel Fox 2I
Mon Oct 26, 2020 10:19 pm
Forum: Empirical & Molecular Formulas
Topic: Limiting Reactant Calculations Module #22
Replies: 2
Views: 40

Limiting Reactant Calculations Module #22

According to the following equation, 0.750 g of C6H9Cl3 is mixed with 1.000 kg of AgNO3 in a flask of water. A white solid, AgCl, completely precipitates out. What is the mass of AgCl produced? C6H9Cl3 + 3AgNO3 ---> AgCl + C6H9(NO3)3. Molar Mass: C6H9Cl3 (187.50 g/mol), 3AgNO3 (169.88 g/mol), AgCl (...
by Racquel Fox 2I
Mon Oct 26, 2020 10:08 pm
Forum: Properties of Light
Topic: Tips for knowing what equation to use?
Replies: 5
Views: 74

Re: Tips for knowing what equation to use?

I think you would use De Broglie's equation anytime there is noticeable mass, so if the question is asking about an electron or something along those lines. If the question is asking about a photon, because they are massless, you would use the E=hv equation.
by Racquel Fox 2I
Mon Oct 26, 2020 10:06 pm
Forum: Photoelectric Effect
Topic: Moles of atoms/photons
Replies: 3
Views: 39

Re: Moles of atoms/photons

I'm not sure if this answers your question, but if you have 1 e-, you would divide by 6.022*10^23 to find the moles of e-
by Racquel Fox 2I
Mon Oct 26, 2020 9:06 pm
Forum: Properties of Electrons
Topic: Sapling Homework #14
Replies: 5
Views: 78

Re: Sapling Homework #14

I'm pretty sure n2 = 7, and with that you would get the v = R((1/n1^2) - (1/n2^2)) to be 3.29*10^15 x ((1/4)-(1/49)).
by Racquel Fox 2I
Mon Oct 26, 2020 8:58 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Inconsistencies in Delta Values
Replies: 4
Views: 53

Re: Inconsistencies in Delta Values

I'm pretty sure that you generally do 2*y in order to get delta y because that is the same as (5+5 + 5-5). I'm not sure if the textbook is flawed, but I think unless there is a given value for delta y, you would multiply the number after the +/- by 2 in order to find it.
by Racquel Fox 2I
Mon Oct 26, 2020 8:52 pm
Forum: Student Social/Study Group
Topic: Studying Concepts
Replies: 6
Views: 65

Re: Studying Concepts

If you're just starting to study, I would definitely look over the modules on the Chem 14A website for fundamental practice. Also, do the odd numbered exercises in the textbooks for the fundamentals and focus 1 of the quantum information. Good luck!
by Racquel Fox 2I
Mon Oct 26, 2020 8:50 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: sapling question 27
Replies: 3
Views: 43

Re: sapling question 27

In this the problem, they explicitly state that delta v = 0.01*10^6 m/s, so you would just input that number. I'm not completely sure why they give the other number, but it's not relevant to this question.
by Racquel Fox 2I
Mon Oct 26, 2020 7:55 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Change in Velocity Uncertainty
Replies: 4
Views: 67

Change in Velocity Uncertainty

Your bowling ball of mass 4.02kg rolls down a lane with a speed of 2.35 +/- 0.1m/s. What is the minimum indeterminacy of its position? Can you blame the Heisenberg Uncertainty Principle when your ball misses the pins? I'm getting confused on when you multiply the velocity by 2 or when you just use t...
by Racquel Fox 2I
Mon Oct 26, 2020 7:52 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: position units
Replies: 19
Views: 124

Re: position units

I think you would always convert nm to m unless it's specified otherwise.
by Racquel Fox 2I
Mon Oct 26, 2020 7:51 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Sapling Homework #22
Replies: 3
Views: 57

Sapling Homework #22

You can use an electron microscope in which the matter wave associated with the electron beam has a wavelength of 0.0339 nm. What is the kinetic energy of an electron in the beam, expressed in electron volts? I first approached this problem by trying to find the frequency from deriving the c=lambda*...
by Racquel Fox 2I
Mon Oct 26, 2020 7:41 pm
Forum: Balancing Chemical Reactions
Topic: Text Book Problems
Replies: 2
Views: 45

Re: Text Book Problems

I'm not completely sure, but I don't think we'll need to know specific formulaic names. I would just know basic compound names like CO2 and others like that.
by Racquel Fox 2I
Mon Oct 26, 2020 7:40 pm
Forum: Photoelectric Effect
Topic: 1B.15
Replies: 3
Views: 51

Re: 1B.15

I think you would use the E=hv equation because it's referring to the radiation. The way I interpreted that was that it was asking more specifically about the photon, and I'm pretty sure if the question refers to the photon you would use E=hv rather than any other energy equations.

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