Search found 106 matches

by zfinn
Sun Mar 15, 2020 9:03 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Seeing how many electrons transfer
Replies: 2
Views: 51

Re: Seeing how many electrons transfer

i usually find it easiest to just split into half reactions, finding the number of e- by looking at change in oxidation numbers
by zfinn
Sun Mar 15, 2020 9:01 pm
Forum: Balancing Redox Reactions
Topic: Oxidation/Reduction
Replies: 17
Views: 159

Re: Oxidation/Reduction

i look at the atom to determine it, but when asking for the species put the whole molecule
by zfinn
Sun Mar 15, 2020 8:52 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic and Voltaic
Replies: 5
Views: 62

Re: Galvanic and Voltaic

i think the book says they're the same thing, just different names. the two different types would be galvanic/voltaic and electrolytic cells.
by zfinn
Sun Mar 15, 2020 8:51 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius eq
Replies: 5
Views: 56

Re: Arrhenius eq

it's useful in situations where you want to see how the rate, temperature, and activation energy all relate
by zfinn
Sun Mar 15, 2020 8:49 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: adding platinum
Replies: 8
Views: 74

Re: adding platinum

If there isn't a viable metal electrode listed in the equation then platinum can be used/put in the diagram
by zfinn
Sun Mar 15, 2020 8:47 pm
Forum: Administrative Questions and Class Announcements
Topic: Athena
Replies: 34
Views: 1825

Re: Athena

thank you for such a fun past two quarters! we've all learned so much and are so lucky to have such an amazing professor.
by zfinn
Sun Mar 15, 2020 8:44 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Ea, rate, and temperature
Replies: 4
Views: 50

Re: Ea, rate, and temperature

if i understand correctly, raising temp will affect the rates most of reactions that are endothermic (heat using) with large activation energies.
by zfinn
Sun Mar 15, 2020 8:42 pm
Forum: Balancing Redox Reactions
Topic: Test 2 Return
Replies: 20
Views: 239

Re: Test 2 Return

if you have sabina i think they're in her mailbox!
by zfinn
Sun Mar 15, 2020 8:41 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Doing work vs work done
Replies: 8
Views: 102

Re: Doing work vs work done

when w is positive work is done on the system
by zfinn
Sun Mar 15, 2020 8:39 pm
Forum: Balancing Redox Reactions
Topic: Half rxns
Replies: 27
Views: 297

Re: Half rxns

with acidic you add h2o to balance oxygen and then simply h+ to balance the hydrogen, but with basic you add h2o to balance oxygen but then need to balance the hydrogens with oh-, while adding h2o to balance any additional oxygens.
by zfinn
Sun Mar 08, 2020 12:11 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: intermediates
Replies: 5
Views: 60

Re: intermediates

i doubt we’ll have to guess/make up any intermediates but you should know what they are and how to identify them
by zfinn
Tue Mar 03, 2020 10:50 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Relationship Between Ecell and K
Replies: 9
Views: 66

Relationship Between Ecell and K

what's the relationship between Ecell and the value of K? (i.e. if K > 1 or K <1)
by zfinn
Tue Mar 03, 2020 5:11 pm
Forum: Van't Hoff Equation
Topic: 5J.15
Replies: 1
Views: 65

5J.15

can someone explain problem 5J.15? even after looking at the solutions guide i'm still a bit confused on how to start, and also just the steps to solve the equation. thanks so much!
by zfinn
Mon Mar 02, 2020 3:35 pm
Forum: Administrative Questions and Class Announcements
Topic: corresponding questions for 2nd pg of thermo outline
Replies: 2
Views: 31

corresponding questions for 2nd pg of thermo outline

what sections of the book/which problems correspond to the second page of the thermodynamics outline?
by zfinn
Sun Mar 01, 2020 7:00 pm
Forum: Balancing Redox Reactions
Topic: Oxidizing/reducing agent
Replies: 18
Views: 151

Re: Oxidizing/reducing agent

the oxidizing agent is being reduced because it is recieving the e- from reduction process, and the reducing agent is being oxidized because it is giving e- for the reduction process.
by zfinn
Sun Mar 01, 2020 6:54 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6L.1
Replies: 1
Views: 22

Re: 6L.1

in the process C4+ --> C3+ one electron is gained.
the balanced equation has 2C4+ so therefore 2*1e- = 2e-, and n=2. hope this makes sense!
by zfinn
Sun Mar 01, 2020 6:51 pm
Forum: Van't Hoff Equation
Topic: Deriving [ENDORSED]
Replies: 2
Views: 50

Re: Deriving [ENDORSED]

this is how we did it in my discussion
by zfinn
Sun Mar 01, 2020 6:48 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram Comma vs Line
Replies: 5
Views: 29

Re: Cell Diagram Comma vs Line

a comma is used if elements are in the same phase, for example of both are aqueous
by zfinn
Sun Mar 01, 2020 6:32 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: N value
Replies: 7
Views: 65

Re: N value

yep! unless one half reaction has 2e- and the other has 4e-, then n=4 because it is the lowest common multiple.
by zfinn
Sun Mar 01, 2020 6:30 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Salt Bridge
Replies: 3
Views: 45

Re: Salt Bridge

if there is no salt bridge in an electrolytic cell it's because the anode and cathode can be in the same solution, so a salt bridge wouldn't be necessary (i think).
by zfinn
Sun Feb 23, 2020 11:18 pm
Forum: Balancing Redox Reactions
Topic: spontaneous
Replies: 15
Views: 129

Re: spontaneous

when the standard reaction potential is positive, the rxn will spontaneously proceed in the forward direction
by zfinn
Sun Feb 23, 2020 11:16 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: STP
Replies: 13
Views: 98

Re: STP

1 atm and 273.5K, although in the midterm it was written on the board so i'm assuming if you don't memorize it it could be okay (?)
by zfinn
Sun Feb 23, 2020 11:11 pm
Forum: Van't Hoff Equation
Topic: Thermo in Test 2
Replies: 6
Views: 67

Re: Thermo in Test 2

the 2nd page of outline 4 will definitely be covered, but personally i might to brush up on some of the concepts beforehand too just in case it's implicitly tested!
by zfinn
Sun Feb 23, 2020 11:10 pm
Forum: Balancing Redox Reactions
Topic: Oxidation?
Replies: 10
Views: 68

Re: Oxidation?

oxidation is loss of electrons, which means the charge of the oxidized atom will increase - the acronym OIL RIG is helpful for me (Oxidation Is Loss (of e-), Reduction Is Gain (of e-))
by zfinn
Sun Feb 23, 2020 11:06 pm
Forum: Balancing Redox Reactions
Topic: Half reactions
Replies: 17
Views: 146

Re: Half reactions

it is balanced when there is an equal number of electrons on each side that can cancel out
by zfinn
Sun Feb 16, 2020 10:51 pm
Forum: General Science Questions
Topic: Content on Test 2
Replies: 10
Views: 105

Re: Content on Test 2

that's my best guess, yeah. but you should probably check with ur ta in discussion this week just to make sure!
by zfinn
Sun Feb 16, 2020 10:49 pm
Forum: General Science Questions
Topic: homework for week 7
Replies: 7
Views: 65

homework for week 7

what homework should we turn in to discussion for week 7?
by zfinn
Sun Feb 16, 2020 10:48 pm
Forum: General Science Questions
Topic: What are Workshops?
Replies: 10
Views: 186

Re: What are Workshops?

my understanding is that step-up is in detail teaching of the topic, while workshop is more about going over questions that students may have (not as step by step/in depth)
by zfinn
Sun Feb 16, 2020 10:45 pm
Forum: Calculating Work of Expansion
Topic: Using Calculus to prove the equation
Replies: 4
Views: 93

Re: Using Calculus to prove the equation

Drew Myers 4G wrote:Can someone explain how to use calculus to prove
w = -PΔV?

does anyone know if we will be tested on this?
by zfinn
Sun Feb 16, 2020 10:43 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: isothermal reactions
Replies: 8
Views: 141

Re: isothermal reactions

isothermal reactions mean there is no change in temperature, and therefore it can't have a change in internal energy
by zfinn
Sun Feb 16, 2020 10:42 pm
Forum: General Science Questions
Topic: Content on Test 2
Replies: 10
Views: 105

Re: Content on Test 2

I think the way it was last quarter was material from midterm to test 2
by zfinn
Tue Feb 11, 2020 7:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Pizza Rolls REVIEW Session DOWNLOAD HERE
Replies: 67
Views: 2646

Re: Pizza Rolls REVIEW Session DOWNLOAD HERE

For Pizza Rolls 5e why is the answer false? is it only crystals that have 0 entropy at absolute zero?
by zfinn
Tue Feb 11, 2020 2:17 pm
Forum: Administrative Questions and Class Announcements
Topic: Pizza Rolls REVIEW Session DOWNLOAD HERE
Replies: 67
Views: 2646

Re: Pizza Rolls REVIEW Session DOWNLOAD HERE

can someone please explain #5 i am very confused. thank you
by zfinn
Sun Feb 09, 2020 8:39 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Volume decrease
Replies: 7
Views: 94

Re: Volume decrease

the rxn will favor the side with less moles of gas, although Dr. Lavelle mentioned that this rule is a quick sub for what is actually happening due to changes in concentration.
by zfinn
Sun Feb 09, 2020 8:34 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: ICE BOX
Replies: 27
Views: 206

Re: ICE BOX

when x is <5% of the initial concentration you can omit it
by zfinn
Tue Feb 04, 2020 11:27 pm
Forum: Calculating Work of Expansion
Topic: Work on a system +/-
Replies: 4
Views: 35

Work on a system +/-

i'm kind of lost on the concept of how to calculate if work is positive or negative in respect to different things, and also the concept of work being "done on" a system. for example, homework problem 4A 3b. thanks!
by zfinn
Mon Feb 03, 2020 12:04 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: state functions
Replies: 10
Views: 71

Re: state functions

state functions only depend on the final value, not the way you got there. for example in a state function it wouldn't matter if you walked down bruinwalk or through the tennis courts to get to Lavelle's lecture, it only matters that you showed up at the lecture and that the lecture is your current ...
by zfinn
Mon Feb 03, 2020 12:00 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Piston Example
Replies: 3
Views: 32

Re: Piston Example

my impression of the example was that the displacement of the piston (moving out) can be used to calculate the change in energy of the system; if you calculate the work function of the piston movement then the energy would've decreased by an amount equal to the energy lost as work done by the system.
by zfinn
Sun Feb 02, 2020 11:56 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: degeneracy
Replies: 7
Views: 50

Re: degeneracy

^ also was it covered in lecture?
by zfinn
Sun Feb 02, 2020 11:54 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: expansion
Replies: 5
Views: 35

Re: expansion

expansion means the volume of the system increases (it expands)
by zfinn
Sun Feb 02, 2020 11:52 pm
Forum: Phase Changes & Related Calculations
Topic: Calorimeters
Replies: 8
Views: 55

Re: Calorimeters

it will affect the problem if it's a bomb calorimeter, because then it's an isolated system
by zfinn
Sun Jan 26, 2020 6:23 pm
Forum: Phase Changes & Related Calculations
Topic: work and heat
Replies: 3
Views: 30

Re: work and heat

work and heat are related to the path taken to the final state, not simply just the final state
by zfinn
Sun Jan 26, 2020 6:16 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1213856

Re: Post All Chemistry Jokes Here

you can call me K because i don't change under pressure
by zfinn
Sun Jan 26, 2020 6:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pressure and equilibrium
Replies: 9
Views: 70

Re: Pressure and equilibrium

Micah3J wrote:Pressure doesn't affect the equilibrium constant though right? It will only shift it one way or the other?


yep! heat is the only measure that affects the equilibrium constant
by zfinn
Sun Jan 26, 2020 6:11 pm
Forum: Ideal Gases
Topic: PV=NRT
Replies: 7
Views: 78

Re: PV=NRT

i don't think we need to know that; if in any way we would it's probably given
by zfinn
Sun Jan 26, 2020 6:10 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: La Chatelier's Principle
Replies: 8
Views: 141

Re: La Chatelier's Principle

the reaction will move away from the side of the concentration increase
by zfinn
Sun Jan 26, 2020 6:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pressure and equilibrium
Replies: 9
Views: 70

Re: Pressure and equilibrium

If the pressure is increased the reaction will go towards the side with fewer gas particles. If you decrease the pressure the reaction will go to the side with more gas particles. this is a good quick way to do it, but Dr.Lavelle also emphasized that the reason behind this shift is how pressure cha...
by zfinn
Sun Jan 26, 2020 6:04 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Kw Equations
Replies: 10
Views: 120

Re: Kw Equations

[h3o+][oh-]=Kw and [Ka][Kb]=Kw
by zfinn
Tue Jan 14, 2020 6:07 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium constants table
Replies: 4
Views: 42

Equilibrium constants table

how do we know which equilibrium constant of the three per equation column (the ones decreasing in value) to use? for example in the Kc column for H2+I2--> 2HI do we use 794, 160, or 54? thanks so much!
by zfinn
Sun Jan 12, 2020 8:40 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: memorization
Replies: 12
Views: 98

Re: memorization

i think we'll usually be able to calculate it, and if not i'm pretty sure it will be given to us, like in the practice problems Dr.Lavelle did in class!
by zfinn
Sun Jan 12, 2020 8:36 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Hw for next week
Replies: 19
Views: 146

Re: Hw for next week

in lecture I remember him mentioning that equilibrium hw for both weeks is okay!
by zfinn
Sun Jan 12, 2020 8:35 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kp vs Kc usage
Replies: 5
Views: 35

Kp vs Kc usage

how do we know when a problem wants us to use Kp versus when we should use Kc? thanks!
by zfinn
Sun Jan 12, 2020 8:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K and Q
Replies: 10
Views: 68

Re: K and Q

Q is the calculation of a system not at equilibrium while K is the calculation of a system at equilibrium (the equilibrium constant).
by zfinn
Sun Jan 12, 2020 8:31 pm
Forum: Ideal Gases
Topic: The Ideal Gas Law
Replies: 3
Views: 30

Re: The Ideal Gas Law

it is ideal because it's assuming that the gas molecules have no attractive forces between themselves, and no molecular volume.
by zfinn
Sun Dec 08, 2019 10:19 pm
Forum: Student Social/Study Group
Topic: Week 10 Chemistry Community
Replies: 9
Views: 277

Re: Week 10 Chemistry Community

AGaeta_4E wrote:I think my number of posts is off by one, is this a problem for anyone else?

sometimes for me the number of posts by my name is wrong, so i have to go to "your posts" and that's usually correct!
by zfinn
Sun Dec 08, 2019 10:17 pm
Forum: Calculating the pH of Salt Solutions
Topic: pH
Replies: 6
Views: 118

Re: pH

The pH is the negative log of the solution's H3O+ concentration. The pOH would be the negative log of its OH- concentration, and this related to pH because pH = 14-pOH.
by zfinn
Sun Dec 08, 2019 10:14 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1213856

Re: Post All Chemistry Jokes Here

Q: What do you do with a sick chemist?
A: If you can't helium, and you can't curium, you might as well barium!
by zfinn
Sat Dec 07, 2019 11:59 am
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4616

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

Ashley Osorio wrote:How would one phrase number 36C?? Also, 36B is both Amphoteric and amphiprotic, right?


" the atoms that give glycine these properties are the N, with a lone pair that can accept a proton, and the -COOH, which can donate a proton." and for 36b it is both!
by zfinn
Fri Dec 06, 2019 3:22 pm
Forum: Hybridization
Topic: Lone pairs in hybridization
Replies: 4
Views: 86

Lone pairs in hybridization

do lone pairs count towards the number of groups attached to the central atom? for example would so2 have 3 groups attached to the central atom? thanks!
by zfinn
Sun Dec 01, 2019 5:46 pm
Forum: Hybridization
Topic: Hybridization and Orbital Shape
Replies: 2
Views: 29

Hybridization and Orbital Shape

How does the hybridization of orbitals change their shape?
by zfinn
Sun Dec 01, 2019 5:37 pm
Forum: Lewis Acids & Bases
Topic: acid v. base?
Replies: 16
Views: 126

Re: acid v. base?

the lewis structure that has a lone pair ready to donate would be a base, while the lewis structure carrying a positive charge is an acid.
by zfinn
Sun Dec 01, 2019 5:31 pm
Forum: General Science Questions
Topic: Memorization for Final
Replies: 2
Views: 44

Memorization for Final

Which concepts or values should we have memorized for the final (that won't be on the equation sheet)? thanks!
by zfinn
Sun Dec 01, 2019 5:26 pm
Forum: Conjugate Acids & Bases
Topic: Conjugate Base
Replies: 5
Views: 67

Re: Conjugate Base

strong acids inherently have a weak conjugate base, which means that its properties would not change the pH of a solution.
by zfinn
Sun Dec 01, 2019 5:18 pm
Forum: Lewis Acids & Bases
Topic: bronsted vs lewis
Replies: 9
Views: 83

Re: bronsted vs lewis

bronsted acids and bases identify the exchange of protons while lewis deal with the exchange of electrons. they aren't necessarily two separate groups, just different ways of viewing acids and bases.
by zfinn
Sun Nov 24, 2019 2:03 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs linear
Replies: 56
Views: 731

Re: Bent vs linear

bent will have 1 or 2 lone pairs (AX2E oe AX2E2) while linear will have none or 3 (AX2 or AX2E3)!
by zfinn
Sun Nov 24, 2019 1:56 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Seesaw
Replies: 23
Views: 197

Re: Seesaw

The bond angles would be less because lone-bonding pars have more repulsion
by zfinn
Sun Nov 24, 2019 12:57 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: AXE Format
Replies: 34
Views: 220

Re: AXE Format

there's no need to write the "1" subscript for X and E!
by zfinn
Sun Nov 24, 2019 12:53 pm
Forum: Dipole Moments
Topic: Hydrogen bonding
Replies: 5
Views: 77

Re: Hydrogen bonding

hydrogen bonding sites are wherever an H can bond with a F,O, or N
by zfinn
Mon Nov 18, 2019 11:05 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: How to know which angles are smaller
Replies: 8
Views: 64

How to know which angles are smaller

in a VSEPR shape with more than one angle size, i.e. seesaw, would all the angles decrease because of the lone pair (so angles are <90, <120, <180)? or do just the angles next to the lone pair bonding region decrease?
by zfinn
Sun Nov 17, 2019 2:00 pm
Forum: SI Units, Unit Conversions
Topic: Memorizing Conversions
Replies: 23
Views: 485

Re: Memorizing Conversions

I'd recommend memorizing them just because it makes converting a lot less seamless from my experience! it's helpful if you can, for example, see 10^-9 and automatically know it's nm.
by zfinn
Sun Nov 17, 2019 1:55 pm
Forum: Hybridization
Topic: Test?
Replies: 6
Views: 65

Re: Test?

If I remember correctly I think that Dr. Lavelle said it would not be on the test.
by zfinn
Sun Nov 17, 2019 1:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angles to know for test 2
Replies: 3
Views: 44

Angles to know for test 2

Which specific VSEPR angle measurements do we need to know for test 2? Thanks!
by zfinn
Sun Nov 17, 2019 1:37 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Octahedral??
Replies: 4
Views: 33

Re: Octahedral??

It's octahedral because the shape of the whole molecule looks like an octahedron (8 faces). It's basically another way to describe the bipyramidal shape, which is two 4-faced pyramids put together, creating an 8 faced shape.
by zfinn
Sun Nov 17, 2019 1:34 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: vapor pressure
Replies: 4
Views: 33

Re: vapor pressure

Since it wasn't explicitly covered in class/discussion I doubt it'll be on the test!
by zfinn
Sun Nov 17, 2019 1:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Van Der Waals Interaction
Replies: 11
Views: 85

Re: Van Der Waals Interaction

any atom that interacts with another atom will have these forces because it has electrons that are available for induced dipole movement. that being said, larger atoms have stronger van der waals forces because they have more electrons.
by zfinn
Sun Nov 17, 2019 1:28 pm
Forum: Bond Lengths & Energies
Topic: Bond lengths
Replies: 8
Views: 79

Re: Bond lengths

I think the bond lengths do vary slightly depending on the atoms, based on their electron affinity.
by zfinn
Sun Nov 17, 2019 1:26 pm
Forum: General Science Questions
Topic: Test 2
Replies: 7
Views: 73

Re: Test 2

It should cover everything since the midterm up to friday's lecture (+the concepts from one slide on monday)
by zfinn
Tue Nov 05, 2019 8:48 pm
Forum: Administrative Questions and Class Announcements
Topic: DINO NUGGETS Review Session! Download Problems HERE [ENDORSED]
Replies: 52
Views: 4711

Re: DINO NUGGETS Review Session! Download Problems HERE [ENDORSED]

Hi! a few more questions on the dino nuggets review - can anyone explain the reason behind the answers to 9.e, 9.f, or 9.h? also 9.j? Thanks so much in advance!!
by zfinn
Tue Nov 05, 2019 3:08 pm
Forum: SI Units, Unit Conversions
Topic: When to use scientific notation
Replies: 4
Views: 148

When to use scientific notation

How do we tell when we should convert our answers into scientific notation? I'm never sure when or when not to - thanks so much!
by zfinn
Tue Nov 05, 2019 3:00 pm
Forum: Administrative Questions and Class Announcements
Topic: DINO NUGGETS Review Session! Download Problems HERE [ENDORSED]
Replies: 52
Views: 4711

Re: DINO NUGGETS Review Session! Download Problems HERE [ENDORSED]

for dino nuggets #4 why is the answer 2 sig figs and not 3? is it because 250 mL has only 2 sig figs? i'm a bit confused if that's the reason or if it's something else - if someone could clarify that would be great! thanks so much
by zfinn
Sun Nov 03, 2019 9:15 pm
Forum: Properties of Light
Topic: What are the units of hertz
Replies: 41
Views: 392

Re: What are the units of hertz

1 cycle/second or in calculation basically s^-1
by zfinn
Sun Nov 03, 2019 9:11 pm
Forum: Electronegativity
Topic: Trends of the Periodic Table
Replies: 3
Views: 64

Re: Trends of the Periodic Table

these ones were on a worksheet my ta gave me!
by zfinn
Sun Nov 03, 2019 9:06 pm
Forum: Empirical & Molecular Formulas
Topic: Rounding
Replies: 6
Views: 221

Re: Rounding

I usually just see if multiplying by a number will clearly make it even. i.e if it is 1.66, even though that is close-is to 2, it is easy to see that multiplying by 3 will get us much closer to a whole number. if the number is like 1.97 though it's definitely safe to round up!
by zfinn
Sun Nov 03, 2019 9:03 pm
Forum: Lewis Structures
Topic: Octet Rule
Replies: 6
Views: 72

Re: Octet Rule

The octet rule means that most atoms are most comfortable/stable when they gain enough electrons to form an octet, and imitate the e- configuration of a noble gas.
by zfinn
Sun Nov 03, 2019 9:00 pm
Forum: Quantum Numbers and The H-Atom
Topic: Rules for n, l,m
Replies: 11
Views: 142

Re: Rules for n, l,m

principle quantum # = n = energy & size (shell)
angular momentum = l = can be anything up to (n-1)
magnetic number = ml = orientation, -l....l
spin number = ms = -1/2 or +1/2
by zfinn
Fri Oct 25, 2019 2:46 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 5 Homework
Replies: 9
Views: 96

Re: Week 5 Homework

The chemical bonds homework, because that's what we spent most of this week covering! and I think it'll translate better into what we discuss in discussion next week too.
by zfinn
Fri Oct 25, 2019 2:43 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Number of Valence Electrons
Replies: 5
Views: 77

Re: Number of Valence Electrons

It would have 7 valence e- (from d and s), and would more readily loose e- from the 4s shell.
by zfinn
Fri Oct 25, 2019 2:39 pm
Forum: Lewis Structures
Topic: Charges on atoms with lower e- affinity
Replies: 4
Views: 41

Re: Charges on atoms with lower e- affinity

Selena Yu 1I wrote:Dr. Lavelle was saying that you shouldn't put more charges on a lower electron affinity molecule because that would make the whole lewis structure less stable, which is what you don't want.

Does more charges include both negative and positive charges (for the FC)?
by zfinn
Fri Oct 25, 2019 2:37 pm
Forum: Properties of Light
Topic: Value of the speed of light
Replies: 3
Views: 57

Value of the speed of light

In my homework I usually use c=3.00*10^8 as the constant for speed of light, but I've noticed that in the answer booklet they use c=2.99792*10^8. Due to sig figs rounding my answer is almost always the same as if I were to use c=2.99792*10^8 like the book, but I'm wondering if there will ever be a t...
by zfinn
Fri Oct 25, 2019 2:26 pm
Forum: Properties of Electrons
Topic: Mass of electron in 1B.15
Replies: 3
Views: 48

Mass of electron in 1B.15

In homework problem 1B.15 (from the quantum section) were we expected to know the mass of the electron? Or is it okay to look that info up/will it be provided on a constants sheet for the test? Thanks so much!
by zfinn
Fri Oct 25, 2019 2:21 pm
Forum: Lewis Structures
Topic: Charges on atoms with lower e- affinity
Replies: 4
Views: 41

Charges on atoms with lower e- affinity

In today's lecture Dr. Lavelle mentioned that when creating Lewis Structures you didn't want to, "put more charges on an atom with lower electron affinity." I was wondering what this meant in the context of Lewis Structures, and the reasoning behind it? thanks so much!
by zfinn
Sat Oct 19, 2019 10:36 pm
Forum: Student Social/Study Group
Topic: Homework for Week 4
Replies: 4
Views: 77

Homework for Week 4

For our week four homework do we just do 5 more problems from "The Quantum World" section? Thanks in advance!
by zfinn
Sat Oct 19, 2019 10:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Resources
Replies: 2
Views: 58

Re: Resources

If you purchased the loose leaf textbook you should be able to access the resources for free on the site! If you didn't purchase the book though you might have to pay (but I'm not too sure).
by zfinn
Sat Oct 19, 2019 10:25 pm
Forum: General Science Questions
Topic: Tests
Replies: 9
Views: 118

Re: Tests

I think my TA mentioned that just to be safe we should memorize them, in case they happen to be missing from the formula sheet.
by zfinn
Sat Oct 19, 2019 10:24 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Inner e- and Outer e-
Replies: 14
Views: 114

Re: Inner e- and Outer e-

The inner electrons "shield" the outer ones from the nuclear charge, which causes the outer ones to be lost easier, since they aren't as strongly attracted anymore (due to shielding).
by zfinn
Sat Oct 19, 2019 10:21 pm
Forum: Photoelectric Effect
Topic: Intensity of Light
Replies: 5
Views: 71

Re: Intensity of Light

The way I understood it is that the intensity is what effects the amount of photons ejected. The frequency determines if a photon will have enough energy to eject an electron. But if you increase intensity it will double the photons which will double the amount of electrons ejected (at least I remem...
by zfinn
Sun Oct 13, 2019 3:57 pm
Forum: Properties of Light
Topic: Memorization of Electromagnetic Spectrum
Replies: 3
Views: 59

Memorization of Electromagnetic Spectrum

For this course do we have to have all the values in the electromagnetic spectrum memorized?
by zfinn
Sun Oct 13, 2019 3:15 pm
Forum: SI Units, Unit Conversions
Topic: knowing how many sig figs to use
Replies: 17
Views: 231

Re: knowing how many sig figs to use

You should keep as many sig figs as possible while you work on the problem in order to be the most accurate. Then at the end, you can round to the correct number!
by zfinn
Sat Oct 12, 2019 5:57 pm
Forum: Properties of Electrons
Topic: Diffraction
Replies: 4
Views: 63

Re: Diffraction

If two waves are "in phase" this means that they both peak at the same time (their highest points are at the same time). "Out of phase" would be when their peaks don't line up.
by zfinn
Sat Oct 12, 2019 5:50 pm
Forum: Properties of Light
Topic: c vs. v...
Replies: 3
Views: 68

Re: c vs. v...

c=(lambda)(v) is the wave equation so I think you can use it to solve for the wavelength or frequency of any wave (as long as you're given/find one or the other before using the equation)

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