Search found 65 matches

by connie ma 3G
Sun Jan 24, 2021 1:01 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Units for Standard Reaction Enthalpy
Replies: 3
Views: 17

Re: Units for Standard Reaction Enthalpy

im pretty sure that the standard reaction enthalpy is for however many moles of a compound is used/produced in a reaction which is why its in units of kJ not kJ/mole. standard enthalpy of formation however is always the enthalpy for the formation of ONE MOLE of a compound which is why its in kJ/mole...
by connie ma 3G
Sun Jan 24, 2021 12:57 pm
Forum: Student Social/Study Group
Topic: Comfort Movies
Replies: 119
Views: 267

Re: Comfort Movies

Jurassic World. i love when the people get eaten it puts my mind at rest.
by connie ma 3G
Sun Jan 24, 2021 12:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Difference between K and Kc
Replies: 10
Views: 24

Re: Difference between K and Kc

K is just the general term for equilibrium constant. you specify Kc or Kp depending on what you're working with but K just refers to both
by connie ma 3G
Sun Jan 24, 2021 12:51 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5% rule for checking the validity of assumptions
Replies: 3
Views: 12

Re: 5% rule for checking the validity of assumptions

im not sure but i feel like it would apply to partial pressures as well since the concept behind the approximation is the same. i would definitely double check with someone else maybe the professor or a TA to make sure though.
by connie ma 3G
Sun Jan 24, 2021 12:49 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Midterm
Replies: 1
Views: 7

Re: Midterm

no. he said in an email that only the topics covered this past week from outline 3 will be on the midterm so that includes 4D3, 4D4, 4D5, and 4E3 from the textbook
by connie ma 3G
Sat Jan 16, 2021 12:12 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Autoprotolysis
Replies: 5
Views: 36

Re: Autoprotolysis

someone already gave an excellent answer to your question but adding on to it, i think the main purpose of showing us the autoprotolysis of water was so we would understand why [H+][OH-]=10^-14. it just provides us context on where that concept came from since we use it a lot.
by connie ma 3G
Sat Jan 16, 2021 12:09 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: ICE Box
Replies: 28
Views: 74

Re: ICE Box

we use the ice chart for weak acids/bases to better visualize the changes that are occurring in solution. strong acids/bases dissociate 100% which makes the calculations very simple so we dont need the ice charts. you can definitely still use the ice chart for strong acids/bases if you want to but i...
by connie ma 3G
Sat Jan 16, 2021 12:06 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: pH of conjugate acid/base
Replies: 3
Views: 28

Re: pH of conjugate acid/base

not really sure what you mean by calculating the pH of the "conjugate". i think when you calculate pH you're measuring the acidity/basicity levels of an entire solution not a single compound. also when you subtract pKa or pKb from 14 then you get the other value, if thats what youre asking...
by connie ma 3G
Fri Jan 15, 2021 2:40 pm
Forum: Administrative Questions and Class Announcements
Topic: acids and bases on the midterm
Replies: 6
Views: 35

acids and bases on the midterm

will the midterm only test us on the acids and bases content that we learned in 14B or will we also be tested on the acids and bases content from last quarter in 14A?
by connie ma 3G
Thu Jan 14, 2021 4:53 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Lecture example
Replies: 1
Views: 33

Lecture example

in the example professor gave with acetic acid on wednesdays lecture around 22:30, he said that it was acting as a base. but im confused because the acetic acid donated the H+ ion to the water molecule to form H3O+ so why is it considered a base?
by connie ma 3G
Sat Jan 09, 2021 2:34 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Le Chatelier's Principle
Replies: 4
Views: 23

Re: Le Chatelier's Principle

like the poster above said, it seems possible! however i think in the context of this unit we wouldnt need to worry about such a scenario and i think the main takeaway from that example was just to understand how the equilibrium would shift when more reactants or products are added.
by connie ma 3G
Sat Jan 09, 2021 2:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Inert Gas Pressure Change
Replies: 3
Views: 14

Re: Inert Gas Pressure Change

i think Professor Lavelle wanted to mainly emphasize the fact that volume HAS to decrease for the equilibrium to change. because a lot of people may assume that increasing pressure/decreasing volume and decreasing pressure/increasing volume are things that happen simultaneously. he used inert gas as...
by connie ma 3G
Sat Jan 09, 2021 2:19 pm
Forum: Ideal Gases
Topic: value of R
Replies: 24
Views: 75

value of R

in the ideal gas law PV=nRT i know that R can take on different values. but how do you know which value to use? theres 4 different R values on our equation sheet and im not sure when you would use each one.
by connie ma 3G
Sat Jan 09, 2021 2:16 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: very large K
Replies: 6
Views: 22

very large K

in the lectures Professor Lavelle mentioned that if K is very small (<10^-4) then any change in the reactants side is essentially negligible. i was wondering if the same would hold true if K was very large (>10^4). Would that mean that any change on the products side is negligible?
by connie ma 3G
Mon Jan 04, 2021 11:59 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Temperature/Pressure Effect on Equilibirum (Le Chatlier)
Replies: 4
Views: 35

Re: Temperature/Pressure Effect on Equilibirum (Le Chatlier)

Changing the temperature will shift the equilibrium depending on whether the rxn is endothermic or exothermic. if its endothermic then increasing temperature will shift it right and decreasing temperature will shift it left. if it is exothermic then increasing temperature will shift it left while de...
by connie ma 3G
Tue Dec 15, 2020 2:36 pm
Forum: Student Social/Study Group
Topic: Staying Motivated
Replies: 20
Views: 119

Re: Staying Motivated

I study with my sister and we do "focus sessions" where we set a timer for 25 minutes of uninterrupted work time and then break for 5 minutes and repeat :) you can totally adjust the time to what you prefer and study alone if you don't have any siblings but I find studying together us keep...
by connie ma 3G
Sun Dec 13, 2020 1:28 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Textbook problem 6C.17
Replies: 4
Views: 59

Textbook problem 6C.17

"Which is the stronger base, the hypobromite ion, BrO-, or
morphine, C17H19O3N? Justify your answer."

How would we answer this without knowing the pKb values that the answer guide references?
by connie ma 3G
Sat Dec 12, 2020 11:00 pm
Forum: Naming
Topic: Textbook 9C.1 Naming Question
Replies: 4
Views: 24

Re: Textbook 9C.1 Naming Question

yes OH2 is just H2O (im pretty sure at least). I dont know why they write it like that but I assumed it is water because of the "aqua" part in the name.
by connie ma 3G
Sat Dec 12, 2020 10:57 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: polydentate ligands
Replies: 5
Views: 51

polydentate ligands

will we need to know specific polydentate ligands such as "en," "edta," or oxalato for the final?
by connie ma 3G
Sat Dec 12, 2020 6:20 pm
Forum: Hybridization
Topic: Textbook problem 2F1
Replies: 3
Views: 35

Textbook problem 2F1

"State the relative orientations of each of the following hybrid orbitals
(a) sp3 ;(b) sp ;(c) sp3d2 ;(d) sp2"

Can someone explain this to me? Is this something we need to know for the final?
by connie ma 3G
Sun Dec 06, 2020 12:53 am
Forum: Bronsted Acids & Bases
Topic: neutralization
Replies: 3
Views: 39

Re: neutralization

to clarify what someone else said, complete neutralization only occurs if its a strong acid reacting with a strong base. if its strong/weak or weak/weak then i dont think complete neutralization occurs.
by connie ma 3G
Sun Dec 06, 2020 12:50 am
Forum: Bronsted Acids & Bases
Topic: Acids strong vs not
Replies: 3
Views: 37

Re: Acids strong vs not

i think what others have said here are pretty good responses. adding on to them and in response to what you originally asked, i dont think the placement of the H in the molecular formula really gives anything away as to the strength of an acid. thats normally to help people determine the placement o...
by connie ma 3G
Sun Dec 06, 2020 12:45 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Effect of Electronegativity on the Strength of Acids
Replies: 4
Views: 50

Re: Effect of Electronegativity on the Strength of Acids

the more electronegative an atom is in a compound the better it is at pulling the electrons/stabilizing the charge on the other atom when the H+ ion is donated. this makes the conjugate base more stable and likely to occur so the acid is stronger.
by connie ma 3G
Tue Dec 01, 2020 9:49 am
Forum: Biological Examples
Topic: oxygen transport process
Replies: 2
Views: 30

Re: oxygen transport process

Hi, The example of oxygen transport is one example of coordination complexes in biological systems. The transition metal in this case is iron, which is bound to multiple different ligands. The first four bonds are from a polydentate, specifically a tetradentate, which means that this same ligand bi...
by connie ma 3G
Mon Nov 30, 2020 11:50 pm
Forum: Biological Examples
Topic: oxygen transport process
Replies: 2
Views: 30

oxygen transport process

Can someone explain the part of Monday's (11/30) lecture where Professor Lavelle discusses the biological importance of coordination complexes in hemoglobin/oxygen transport in our body? I was very confused by that part in the lecture and didn't really get the point he was trying to make so if someo...
by connie ma 3G
Sat Nov 28, 2020 1:12 am
Forum: Determining Molecular Shape (VSEPR)
Topic: How do you know if atoms lie in the same plane?
Replies: 5
Views: 39

Re: How do you know if atoms lie in the same plane?

Adding on to what someone else already said, some of the shapes we learned that has atoms in the same plane would be linear, square planar, and trigonal planar. As you can tell, some of the names of the molecules help give it away. The other shapes like tetrahedral or bent are much more "3d&quo...
by connie ma 3G
Sat Nov 28, 2020 1:04 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Shape vs Polarity
Replies: 11
Views: 72

Re: Shape vs Polarity

I think others may have already said this but to put it in a succinct way, when youre determining shape the only thing that matters is the number and type of bonding regions. So the actual kinds of atoms dont matter. But when youre determining polarity/non polarity then the kinds of atoms do matter ...
by connie ma 3G
Sat Nov 28, 2020 1:00 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Molecular Geometry
Replies: 7
Views: 50

Re: Molecular Geometry

Adding on to what others have said, dont worry too much if its your first time learning molecular shapes. You will pick up faster than you think! When i learned them for the first time in high school, I picked them up super quickly by doing practice with different molecules/compounds. If you cant fi...
by connie ma 3G
Sat Nov 28, 2020 12:53 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Preferential Interactions
Replies: 4
Views: 37

Re: Preferential Interactions

im not sure what preferential interactions are or when/where he mentioned them but (as far as i am aware) i think in general you determine if a molecule is polar or not based on 1) if it has polar bonds and 2) if its shape is polar. if the answer to any of those 2 criteria is no then the molecule is...
by connie ma 3G
Sat Nov 28, 2020 12:43 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: chelates
Replies: 4
Views: 44

chelates

I just watched Wednesday's lecture and am very confused. How do you know/tell if a ligand is going to form a ring of atoms that would make the complex into a chelate?
by connie ma 3G
Fri Nov 20, 2020 10:11 pm
Forum: Student Social/Study Group
Topic: Favorite TV shows
Replies: 178
Views: 879

Re: Favorite TV shows

stranger things is a must if u havent seen it yet. i think of it as an all around good show that a lot of different people can enjoy. my favorite show is the vampire diaries if youre into attractive characters, bad acting, and a dramatic plot line lol. criminal minds is also very intriguing and addi...
by connie ma 3G
Mon Nov 16, 2020 6:16 pm
Forum: Ionic & Covalent Bonds
Topic: textbook problem 2D3 and 2D5
Replies: 3
Views: 32

textbook problem 2D3 and 2D5

Hi, can someone explain how we are supposed to solve these without knowing the exact electronegativity values/differences between elements? 2D3: Which of these compounds has bonds that are primarily ionic? (a) BBr3; (b) BaBr2; (c) BeBr2. 2D5: For each pair, determine which compound has bonds with gr...
by connie ma 3G
Mon Nov 16, 2020 3:06 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook problem 2A17
Replies: 4
Views: 34

Textbook problem 2A17

2A17: Predict the number of valence electrons present for each of the following ions:(a) Mn^4+ ; (c) Co^3+ Textbook Answers: (a) 3 ; (c) 6 Why do they only count the valence electrons in the 3d orbital? For example, in part (a) if 4 electrons were removed from Mn then 2 of those electrons would be r...
by connie ma 3G
Mon Nov 16, 2020 2:44 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook problems 2A9 and 2A11
Replies: 3
Views: 21

Re: Textbook problems 2A9 and 2A11

It's asking for exactly what it says, M is an unknown metal whose ground-state electron configuration is given and we need to figure out what element M is. So you basically need to work backwards from how you normally would write an element's electron configuration. Just count the number of electro...
by connie ma 3G
Mon Nov 16, 2020 2:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook problems 2A9 and 2A11
Replies: 3
Views: 21

Textbook problems 2A9 and 2A11

Hi can anyone explain these textbook problems? I have absolutely no idea what theyre asking for and how they got the answer. 2A9: Which M^2+ ions (where M is a metal) are predicted to have the following ground-state electron configurations: (a) [Ar]3d7; (b) [Ar]3d6? Textbook Answers: a) Co^2+ b) Fe^...
by connie ma 3G
Sun Nov 15, 2020 3:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm 2 format?
Replies: 9
Views: 95

Re: Midterm 2 format?

its going to be multiple choice. as far as difficulty goes i dont think anyone really knows for sure but i think the general consensus on the first midterm was that it was easier so i wouldnt be surprised if this midterm was slightly more difficult.
by connie ma 3G
Sun Nov 15, 2020 3:31 pm
Forum: Electronegativity
Topic: Electronegativity
Replies: 9
Views: 78

Re: Electronegativity

going down the periodic table there is an increase in the atomic radius/number of "shells" which increases the shielding effect and decreases the zeff. as a result there is less "pull" for electrons.
by connie ma 3G
Sun Nov 15, 2020 3:28 pm
Forum: Student Social/Study Group
Topic: Studying Tips
Replies: 23
Views: 159

Re: Studying Tips

i always reread my notes and then do the textbook/sapling questions and normally thats enough for me!
by connie ma 3G
Wed Nov 11, 2020 9:15 pm
Forum: Bond Lengths & Energies
Topic: ion-dipole vs H-bond
Replies: 4
Views: 37

Re: ion-dipole vs H-bond

You are confusing ionic bonds with H-Bonds. Ionic bonds are the bonds that form between a nonmetal and metal atom. Those are of course stronger than any intermolecular force. Any bond that forms between atoms will always be stronger than the bond formed between molecules in general. However, he sai...
by connie ma 3G
Wed Nov 11, 2020 5:54 pm
Forum: Bond Lengths & Energies
Topic: ion-dipole vs H-bond
Replies: 4
Views: 37

ion-dipole vs H-bond

In the lecture from Monday 11/9 around the 56:38 time stamp Dr. Lavelle orders the IMFs from strongest to weakest and he puts H-bonds above ion-dipoles. However, in high school chemistry and according to google searches, ion-dipole is supposedly stronger than H-bonds. Can anyone confirm or deny this...
by connie ma 3G
Thu Nov 05, 2020 2:02 pm
Forum: Formal Charge and Oxidation Numbers
Topic: most stable lewis structure/formal charge
Replies: 6
Views: 67

Re: most stable lewis structure/formal charge

Hello! In regards to the possibility of a sulfur atom having four double bonds, I'm almost certain it's impossible. Even though Lavelle has mentioned that S can have an expanded octet, four double bonds would correspond to 16 electrons, and the maximum amount of valence electrons S can accommodate ...
by connie ma 3G
Thu Nov 05, 2020 10:57 am
Forum: Formal Charge and Oxidation Numbers
Topic: Lewis structures and formal charge
Replies: 4
Views: 22

Re: Lewis structures and formal charge

Could someone explain a bit more on why atoms with high electron affinities would be more stable with a negative formal charge and vice versa? Thanks! I think it's because a negative formal charge indicates that there are more electrons bonded to that atom in the structure compared to the number of...
by connie ma 3G
Thu Nov 05, 2020 10:32 am
Forum: Formal Charge and Oxidation Numbers
Topic: most stable lewis structure/formal charge
Replies: 6
Views: 67

most stable lewis structure/formal charge

In the lectures Dr. Lavelle gave examples with the sulfate ion SO4 2- and showed that it is generally more stable when there are two double bonds and two single bonds between the S and O atoms (expanded octet) as opposed to just 4 single bonds (not expanded octet) because it brings the formal charge...
by connie ma 3G
Thu Nov 05, 2020 10:21 am
Forum: Formal Charge and Oxidation Numbers
Topic: Lewis structures and formal charge
Replies: 4
Views: 22

Lewis structures and formal charge

If a structure could not have formal charges of all 0, and some of them had to be either positive or negative values, which atoms should these +/- values be placed on to achieve the most stable structure?
by connie ma 3G
Thu Nov 05, 2020 12:20 am
Forum: Lewis Structures
Topic: Chemical Formulas
Replies: 8
Views: 55

Re: Chemical Formulas

Like someone else said, there is a list of common polyatomic ions that are helpful to know just because they are so commonly used/seen. I think most high school chemistry classes make you memorize them. Other than that, I think the formulas for the more uncommon compounds are normally given to us.
by connie ma 3G
Thu Oct 29, 2020 8:56 pm
Forum: Photoelectric Effect
Topic: Electron Properties
Replies: 4
Views: 58

Re: Electron Properties

for the problems we've been doing and practicing with, if the wavelength is less than 10^-15 m then we would assume that it is undetectable.
by connie ma 3G
Mon Oct 26, 2020 11:29 pm
Forum: Properties of Light
Topic: increasing intensity
Replies: 5
Views: 58

increasing intensity

Hi, on Brooke Yasuda's (UA) week 2 worksheet the second question is a T/F statement that says: "An increase in intensity means an increase in energy." Her answer was: "Trick Question! Depends on if you are taking into account the wave characteristic of light or the particle characteri...
by connie ma 3G
Mon Oct 26, 2020 10:48 pm
Forum: Einstein Equation
Topic: Sapling HW #4
Replies: 2
Views: 61

Re: Sapling HW #4

Calculate the energy per photon using E=hc/lambda (make sure you convert the cm into meters for the wavelength).

25.34 J represents the total energy absorbed by ALL the photons so divide 25.34 by the E value you calculated above to get the number of photons.
by connie ma 3G
Mon Oct 26, 2020 10:44 pm
Forum: DeBroglie Equation
Topic: De Broglie wavelength
Replies: 3
Views: 20

De Broglie wavelength

What is the cutoff/threshold for a "detectable" de broglie wavelength? How small can the value be for a wavelength and still be counted as detectable? (mainly asking for how small the exponent value on the 10 can be, if that makes sense)
by connie ma 3G
Mon Oct 26, 2020 12:34 am
Forum: Properties of Light
Topic: Textbook problem 1A3
Replies: 2
Views: 23

Textbook problem 1A3

Can explain problem 1A3 from the textbook? I understand why a,b, and d would not happen but I don't understand c even after looking at the student solutions manual. Thanks! Which of the following happens when the frequency of elec- tromagnetic radiation decreases? Explain your reasoning. (a) The spe...
by connie ma 3G
Sun Oct 25, 2020 8:46 pm
Forum: General Science Questions
Topic: Sapling Homework
Replies: 14
Views: 151

Re: Sapling Homework

Yes, the Sapling homework is now due on Week 4, which includes Week 2, 3, 4 material (because Week 2 and 3 were supposed to be due Sunday of Week 3 but now Dr. Lavelle added 10 additional problems from Week 4 content). I would suggest to at least attempt to complete all the Sapling homework before ...
by connie ma 3G
Sat Oct 24, 2020 4:28 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Sapling HOMEWORK #10
Replies: 2
Views: 28

Sapling HOMEWORK #10

Hi can anyone give a step by step process of how to solve this problem from the sapling homework? The electron in a hydrogen atom is excited to the n=7 shell and emits electromagnetic radiation when returning to lower energy levels. Determine the number of spectral lines that could appear when this ...
by connie ma 3G
Sat Oct 24, 2020 2:36 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: When do we use Heisenberg indeterminacy equation
Replies: 10
Views: 70

Re: When do we use Heisenberg indeterminacy equation

Given what we learned, I would say for right now it is limited to the types of calculations/problems we did in the lecture/hw/textbook but for all we know we could be going more in depth with different applications of it in the future.
by connie ma 3G
Sat Oct 24, 2020 2:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Questions on midterm
Replies: 7
Views: 39

Questions on midterm

How many questions should we anticipate being on the midterm? I've heard people say different things and just wanted some clarification on what to expect. Does anyone know?
by connie ma 3G
Fri Oct 23, 2020 11:54 am
Forum: Administrative Questions and Class Announcements
Topic: Schrodingers/Orbitals on Midterm?
Replies: 2
Views: 32

Schrodingers/Orbitals on Midterm?

Sorry if this has already been discussed/answered but is the content from Wednesday's lecture (namely schrodingers and the orbitals) going to be on the midterm? In the lecture and his email, Dr. Lavelle says yes but some people have been saying that he said it will not be on the midterm during his o...
by connie ma 3G
Fri Oct 16, 2020 12:31 am
Forum: Einstein Equation
Topic: Textbook 1A.9
Replies: 2
Views: 33

Re: Textbook 1A.9

First convert the wavelength to m: 2.5 nm = 2.5 x 10^-9 m Then use c=(lambda)(v) to solve for frequency. It should look like 3 x 10^8 = (2.5 x 10^-9)(v) You should get 1.2 x 10^17 Hz Then use the frequency you just calculated to find the E with E=hv. It should look like E = (6.63 x 10^-34)(1.2 x 10^...
by connie ma 3G
Thu Oct 15, 2020 7:34 pm
Forum: SI Units, Unit Conversions
Topic: Webcam
Replies: 11
Views: 126

Re: Webcam

My TA just sent out an email earlier today saying that we can just use an external device to join zoom instead of buying a webcam. I think in that case I'm just gonna use my phone.
by connie ma 3G
Mon Oct 12, 2020 10:50 pm
Forum: Properties of Light
Topic: Photoelectric Effect Post Assessment #34
Replies: 2
Views: 40

Re: Photoelectric Effect Post Assessment #34

First use the given wavelength of the incoming photon to calculate its E (make sure to convert nm to m when you do so): E = hc/lambda E = (6.626 x 10^-34)(3 x 10^8)/(194 x 10^-9) E = 1.02 x 10^-18 J Now use E(photon) - E(threshold) = E(kinetic) (1.02 x 10^-18) - (7.22 x 10^-19) = E(kinetic) E(kineti...
by connie ma 3G
Mon Oct 12, 2020 10:37 pm
Forum: Properties of Light
Topic: Photoelectric effect post assessment 31A
Replies: 2
Views: 56

Re: Photoelectric effect post assessment 31A

Use the equation: E(photon) - E(threshold) = E(kinetic) Since the problem specifies the kinetic energy is 0 then once you plug all the information into the equation it should look like this: E(photon) - (3.607 x 10^-19 J) = 0 This means that E(photon) = 3.607 x 10^-19 J Now use E=hv to solve for v: ...
by connie ma 3G
Mon Oct 12, 2020 10:27 pm
Forum: Photoelectric Effect
Topic: Intensity and Ejecting Election
Replies: 4
Views: 68

Re: Intensity and Ejecting Election

No, if a certain frequency is not enough to eject an electron then increasing the intensity of it will still not meet the threshold energy required to eject the electron. You need to increase the frequency of the radiation. This is because the light is not acting as a wave. Rather, it is acting as a...
by connie ma 3G
Tue Oct 06, 2020 2:47 pm
Forum: Photoelectric Effect
Topic: Audio-visual topics photoelectric effect 28-30
Replies: 1
Views: 61

Re: Audio-visual topics photoelectric effect 28-30

A) use the equation for kinetic energy of a particle: E= 0.5mv^2 where E is the kinetic energy, m is the mass of an electron, and, v is velocity. mass of an electron is a given constant that you can google if you dont know but its 9.11 x 10^-31 kg. the velocity is given in the problem and just plug ...
by connie ma 3G
Tue Oct 06, 2020 2:35 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra Post Mod Q
Replies: 2
Views: 48

Re: Atomic Spectra Post Mod Q

Using C=wavelength x frequency and the wavelength (1850 nm) you were given, calculate the frequency. Make sure you change the wavelength to meters when doing so. Then use the frequency you just calculated and plug it into E=hv to solve for E, the energy per photon. Now divide the TOTAL energy (11J) ...
by connie ma 3G
Tue Oct 06, 2020 2:29 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Atomic Spectra
Replies: 1
Views: 44

Re: Atomic Spectra

Use C=wavelength x frequency to calculate the frequency. Then use the frequency you calculated in the E=hv equation to solve for E.
by connie ma 3G
Mon Oct 05, 2020 4:01 pm
Forum: Molarity, Solutions, Dilutions
Topic: Molarity Question
Replies: 7
Views: 104

Re: Molarity Question

Step 1: convert 5.00 g of KMnO4 to moles. You should get 0.0316 moles. Step 2: convert 150.00 mL to L. You should get 0.15000 L. Step 3: calculate the initial molarity of the solution by using the values you just calculated in steps 1/2. 0.0316 moles/0.15000 L and you should get 0.211 M Step 4: use ...
by connie ma 3G
Mon Oct 05, 2020 2:33 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Module
Replies: 6
Views: 74

Re: Photoelectric Effect Module

Im pretty sure its equivalent to the number of photons. there is a 1:1 interaction ratio. hope this helps!

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