Search found 106 matches
- Sun Mar 15, 2020 9:03 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Seeing how many electrons transfer
- Replies: 3
- Views: 303
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
- Sun Mar 15, 2020 9:01 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation/Reduction
- Replies: 17
- Views: 1130
Re: Oxidation/Reduction
i look at the atom to determine it, but when asking for the species put the whole molecule
- Sun Mar 15, 2020 8:52 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic and Voltaic
- Replies: 5
- Views: 412
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.
- Sun Mar 15, 2020 8:51 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius eq
- Replies: 6
- Views: 431
Re: Arrhenius eq
it's useful in situations where you want to see how the rate, temperature, and activation energy all relate
- Sun Mar 15, 2020 8:49 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: adding platinum
- Replies: 8
- Views: 543
Re: adding platinum
If there isn't a viable metal electrode listed in the equation then platinum can be used/put in the diagram
- Sun Mar 15, 2020 8:47 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Athena
- Replies: 34
- Views: 3056
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.
- Sun Mar 15, 2020 8:44 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Ea, rate, and temperature
- Replies: 4
- Views: 937
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.
- Sun Mar 15, 2020 8:42 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2 Return
- Replies: 20
- Views: 1170
Re: Test 2 Return
if you have sabina i think they're in her mailbox!
- Sun Mar 15, 2020 8:41 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Doing work vs work done
- Replies: 8
- Views: 636
Re: Doing work vs work done
when w is positive work is done on the system
- Sun Mar 15, 2020 8:39 pm
- Forum: Balancing Redox Reactions
- Topic: Half rxns
- Replies: 27
- Views: 1370
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.
- Sun Mar 08, 2020 12:11 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: intermediates
- Replies: 5
- Views: 379
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
- 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: 3171
Relationship Between Ecell and K
what's the relationship between Ecell and the value of K? (i.e. if K > 1 or K <1)
- Tue Mar 03, 2020 5:11 pm
- Forum: Van't Hoff Equation
- Topic: 5J.15
- Replies: 1
- Views: 248
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!
- 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: 231
corresponding questions for 2nd pg of thermo outline
what sections of the book/which problems correspond to the second page of the thermodynamics outline?
- Sun Mar 01, 2020 7:00 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidizing/reducing agent
- Replies: 18
- Views: 1057
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.
- Sun Mar 01, 2020 6:54 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L.1
- Replies: 1
- Views: 134
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!
the balanced equation has 2C4+ so therefore 2*1e- = 2e-, and n=2. hope this makes sense!
- Sun Mar 01, 2020 6:51 pm
- Forum: Van't Hoff Equation
- Topic: Deriving [ENDORSED]
- Replies: 2
- Views: 258
Re: Deriving [ENDORSED]
this is how we did it in my discussion
- 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: 310
Re: Cell Diagram Comma vs Line
a comma is used if elements are in the same phase, for example of both are aqueous
- Sun Mar 01, 2020 6:32 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: N value
- Replies: 7
- Views: 445
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.
- Sun Mar 01, 2020 6:30 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 3
- Views: 231
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).
- Sun Feb 23, 2020 11:18 pm
- Forum: Balancing Redox Reactions
- Topic: spontaneous
- Replies: 15
- Views: 798
Re: spontaneous
when the standard reaction potential is positive, the rxn will spontaneously proceed in the forward direction
- Sun Feb 23, 2020 11:16 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: STP
- Replies: 13
- Views: 713
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 (?)
- Sun Feb 23, 2020 11:11 pm
- Forum: Van't Hoff Equation
- Topic: Thermo in Test 2
- Replies: 6
- Views: 420
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!
- Sun Feb 23, 2020 11:10 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidation?
- Replies: 10
- Views: 673
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-))
- Sun Feb 23, 2020 11:06 pm
- Forum: Balancing Redox Reactions
- Topic: Half reactions
- Replies: 17
- Views: 875
Re: Half reactions
it is balanced when there is an equal number of electrons on each side that can cancel out
- Sun Feb 16, 2020 10:51 pm
- Forum: General Science Questions
- Topic: Content on Test 2
- Replies: 10
- Views: 672
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!
- Sun Feb 16, 2020 10:49 pm
- Forum: General Science Questions
- Topic: homework for week 7
- Replies: 7
- Views: 442
homework for week 7
what homework should we turn in to discussion for week 7?
- Sun Feb 16, 2020 10:48 pm
- Forum: General Science Questions
- Topic: What are Workshops?
- Replies: 10
- Views: 837
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)
- Sun Feb 16, 2020 10:45 pm
- Forum: Calculating Work of Expansion
- Topic: Using Calculus to prove the equation
- Replies: 4
- Views: 495
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?
- Sun Feb 16, 2020 10:43 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: isothermal reactions
- Replies: 8
- Views: 588
Re: isothermal reactions
isothermal reactions mean there is no change in temperature, and therefore it can't have a change in internal energy
- Sun Feb 16, 2020 10:42 pm
- Forum: General Science Questions
- Topic: Content on Test 2
- Replies: 10
- Views: 672
Re: Content on Test 2
I think the way it was last quarter was material from midterm to test 2
- Tue Feb 11, 2020 7:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Pizza Rolls REVIEW Session DOWNLOAD HERE
- Replies: 67
- Views: 5548
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?
- Tue Feb 11, 2020 2:17 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Pizza Rolls REVIEW Session DOWNLOAD HERE
- Replies: 67
- Views: 5548
Re: Pizza Rolls REVIEW Session DOWNLOAD HERE
can someone please explain #5 i am very confused. thank you
- 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: 254
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.
- Sun Feb 09, 2020 8:34 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE BOX
- Replies: 27
- Views: 773
Re: ICE BOX
when x is <5% of the initial concentration you can omit it
- Tue Feb 04, 2020 11:27 pm
- Forum: Calculating Work of Expansion
- Topic: Work on a system +/-
- Replies: 4
- Views: 131
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!
- 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: 339
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 ...
- Mon Feb 03, 2020 12:00 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Piston Example
- Replies: 3
- Views: 131
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.
- Sun Feb 02, 2020 11:56 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: degeneracy
- Replies: 17
- Views: 615
Re: degeneracy
^ also was it covered in lecture?
- Sun Feb 02, 2020 11:54 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: expansion
- Replies: 5
- Views: 298
Re: expansion
expansion means the volume of the system increases (it expands)
- Sun Feb 02, 2020 11:52 pm
- Forum: Phase Changes & Related Calculations
- Topic: Calorimeters
- Replies: 8
- Views: 437
Re: Calorimeters
it will affect the problem if it's a bomb calorimeter, because then it's an isolated system
- Sun Jan 26, 2020 6:23 pm
- Forum: Phase Changes & Related Calculations
- Topic: work and heat
- Replies: 3
- Views: 212
Re: work and heat
work and heat are related to the path taken to the final state, not simply just the final state
- Sun Jan 26, 2020 6:16 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3041862
Re: Post All Chemistry Jokes Here
you can call me K because i don't change under pressure
- Sun Jan 26, 2020 6:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Pressure and equilibrium
- Replies: 9
- Views: 246
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
- Sun Jan 26, 2020 6:11 pm
- Forum: Ideal Gases
- Topic: PV=NRT
- Replies: 7
- Views: 288
Re: PV=NRT
i don't think we need to know that; if in any way we would it's probably given
- 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: 517
Re: La Chatelier's Principle
the reaction will move away from the side of the concentration increase
- Sun Jan 26, 2020 6:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Pressure and equilibrium
- Replies: 9
- Views: 246
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...
- Sun Jan 26, 2020 6:04 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Kw Equations
- Replies: 10
- Views: 504
Re: Kw Equations
[h3o+][oh-]=Kw and [Ka][Kb]=Kw
- Tue Jan 14, 2020 6:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Equilibrium constants table
- Replies: 4
- Views: 168
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!
- Sun Jan 12, 2020 8:40 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: memorization
- Replies: 12
- Views: 574
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!
- Sun Jan 12, 2020 8:36 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Hw for next week
- Replies: 19
- Views: 730
Re: Hw for next week
in lecture I remember him mentioning that equilibrium hw for both weeks is okay!
- Sun Jan 12, 2020 8:35 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp vs Kc usage
- Replies: 5
- Views: 158
Kp vs Kc usage
how do we know when a problem wants us to use Kp versus when we should use Kc? thanks!
- Sun Jan 12, 2020 8:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K and Q
- Replies: 10
- Views: 274
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).
- Sun Jan 12, 2020 8:31 pm
- Forum: Ideal Gases
- Topic: The Ideal Gas Law
- Replies: 3
- Views: 106
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.
- Sun Dec 08, 2019 10:19 pm
- Forum: Student Social/Study Group
- Topic: Week 10 Chemistry Community
- Replies: 9
- Views: 717
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!
- Sun Dec 08, 2019 10:17 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: pH
- Replies: 6
- Views: 344
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.
- Sun Dec 08, 2019 10:14 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3041862
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!
A: If you can't helium, and you can't curium, you might as well barium!
- Sat Dec 07, 2019 11:59 am
- Forum: Administrative Questions and Class Announcements
- Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
- Replies: 115
- Views: 12368
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!
- Fri Dec 06, 2019 3:22 pm
- Forum: Hybridization
- Topic: Lone pairs in hybridization
- Replies: 4
- Views: 373
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!
- Sun Dec 01, 2019 5:46 pm
- Forum: Hybridization
- Topic: Hybridization and Orbital Shape
- Replies: 2
- Views: 127
Hybridization and Orbital Shape
How does the hybridization of orbitals change their shape?
- Sun Dec 01, 2019 5:37 pm
- Forum: Lewis Acids & Bases
- Topic: acid v. base?
- Replies: 16
- Views: 911
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.
- Sun Dec 01, 2019 5:31 pm
- Forum: General Science Questions
- Topic: Memorization for Final
- Replies: 2
- Views: 131
Memorization for Final
Which concepts or values should we have memorized for the final (that won't be on the equation sheet)? thanks!
- Sun Dec 01, 2019 5:26 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate Base
- Replies: 5
- Views: 343
Re: Conjugate Base
strong acids inherently have a weak conjugate base, which means that its properties would not change the pH of a solution.
- Sun Dec 01, 2019 5:18 pm
- Forum: Lewis Acids & Bases
- Topic: bronsted vs lewis
- Replies: 9
- Views: 545
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.
- Sun Nov 24, 2019 2:03 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs linear
- Replies: 56
- Views: 4088
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)!
- Sun Nov 24, 2019 1:56 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Seesaw
- Replies: 23
- Views: 952
Re: Seesaw
The bond angles would be less because lone-bonding pars have more repulsion
- Sun Nov 24, 2019 12:57 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AXE Format
- Replies: 34
- Views: 1107
Re: AXE Format
there's no need to write the "1" subscript for X and E!
- Sun Nov 24, 2019 12:53 pm
- Forum: Dipole Moments
- Topic: Hydrogen bonding
- Replies: 5
- Views: 441
Re: Hydrogen bonding
hydrogen bonding sites are wherever an H can bond with a F,O, or N
- Mon Nov 18, 2019 11:05 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: How to know which angles are smaller
- Replies: 8
- Views: 458
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?
- Sun Nov 17, 2019 2:00 pm
- Forum: SI Units, Unit Conversions
- Topic: Memorizing Conversions
- Replies: 25
- Views: 1306
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.
- Sun Nov 17, 2019 1:55 pm
- Forum: Hybridization
- Topic: Test?
- Replies: 6
- Views: 366
Re: Test?
If I remember correctly I think that Dr. Lavelle said it would not be on the test.
- Sun Nov 17, 2019 1:50 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Angles to know for test 2
- Replies: 3
- Views: 206
Angles to know for test 2
Which specific VSEPR angle measurements do we need to know for test 2? Thanks!
- Sun Nov 17, 2019 1:37 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Octahedral??
- Replies: 4
- Views: 659
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.
- Sun Nov 17, 2019 1:34 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: vapor pressure
- Replies: 4
- Views: 316
Re: vapor pressure
Since it wasn't explicitly covered in class/discussion I doubt it'll be on the test!
- Sun Nov 17, 2019 1:33 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Van Der Waals Interaction
- Replies: 11
- Views: 579
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.
- Sun Nov 17, 2019 1:28 pm
- Forum: Bond Lengths & Energies
- Topic: Bond lengths
- Replies: 8
- Views: 370
Re: Bond lengths
I think the bond lengths do vary slightly depending on the atoms, based on their electron affinity.
- Sun Nov 17, 2019 1:26 pm
- Forum: General Science Questions
- Topic: Test 2
- Replies: 7
- Views: 370
Re: Test 2
It should cover everything since the midterm up to friday's lecture (+the concepts from one slide on monday)
- 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: 6596
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!!
- Tue Nov 05, 2019 3:08 pm
- Forum: SI Units, Unit Conversions
- Topic: When to use scientific notation
- Replies: 4
- Views: 284
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!
- 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: 6596
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
- Sun Nov 03, 2019 9:15 pm
- Forum: Properties of Light
- Topic: What are the units of hertz
- Replies: 41
- Views: 1997
Re: What are the units of hertz
1 cycle/second or in calculation basically s^-1
- Sun Nov 03, 2019 9:11 pm
- Forum: Electronegativity
- Topic: Trends of the Periodic Table
- Replies: 3
- Views: 207
Re: Trends of the Periodic Table
these ones were on a worksheet my ta gave me!
- Sun Nov 03, 2019 9:06 pm
- Forum: Empirical & Molecular Formulas
- Topic: Rounding
- Replies: 6
- Views: 618
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!
- Sun Nov 03, 2019 9:03 pm
- Forum: Lewis Structures
- Topic: Octet Rule
- Replies: 6
- Views: 372
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.
- Sun Nov 03, 2019 9:00 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Rules for n, l,m
- Replies: 11
- Views: 562
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
angular momentum = l = can be anything up to (n-1)
magnetic number = ml = orientation, -l....l
spin number = ms = -1/2 or +1/2
- Fri Oct 25, 2019 2:46 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Week 5 Homework
- Replies: 9
- Views: 407
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.
- Fri Oct 25, 2019 2:43 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Number of Valence Electrons
- Replies: 5
- Views: 346
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.
- Fri Oct 25, 2019 2:39 pm
- Forum: Lewis Structures
- Topic: Charges on atoms with lower e- affinity
- Replies: 4
- Views: 121
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)?
- Fri Oct 25, 2019 2:37 pm
- Forum: Properties of Light
- Topic: Value of the speed of light
- Replies: 3
- Views: 188
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...
- Fri Oct 25, 2019 2:26 pm
- Forum: Properties of Electrons
- Topic: Mass of electron in 1B.15
- Replies: 3
- Views: 166
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!
- Fri Oct 25, 2019 2:21 pm
- Forum: Lewis Structures
- Topic: Charges on atoms with lower e- affinity
- Replies: 4
- Views: 121
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!
- Sat Oct 19, 2019 10:36 pm
- Forum: Student Social/Study Group
- Topic: Homework for Week 4
- Replies: 4
- Views: 183
Homework for Week 4
For our week four homework do we just do 5 more problems from "The Quantum World" section? Thanks in advance!
- Sat Oct 19, 2019 10:31 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Resources
- Replies: 2
- Views: 192
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).
- Sat Oct 19, 2019 10:25 pm
- Forum: General Science Questions
- Topic: Tests
- Replies: 9
- Views: 394
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.
- 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: 464
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).
- Sat Oct 19, 2019 10:21 pm
- Forum: Photoelectric Effect
- Topic: Intensity of Light
- Replies: 5
- Views: 168
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...
- Sun Oct 13, 2019 3:57 pm
- Forum: Properties of Light
- Topic: Memorization of Electromagnetic Spectrum
- Replies: 3
- Views: 153
Memorization of Electromagnetic Spectrum
For this course do we have to have all the values in the electromagnetic spectrum memorized?
- Sun Oct 13, 2019 3:15 pm
- Forum: SI Units, Unit Conversions
- Topic: knowing how many sig figs to use
- Replies: 17
- Views: 771
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!
- Sat Oct 12, 2019 5:57 pm
- Forum: Properties of Electrons
- Topic: Diffraction
- Replies: 4
- Views: 134
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.
- Sat Oct 12, 2019 5:50 pm
- Forum: Properties of Light
- Topic: c vs. v...
- Replies: 3
- Views: 269
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)