Search found 106 matches

by CNourian2H
Sun Mar 15, 2020 12:22 am
Forum: Second Order Reactions
Topic: 1st order vs 2nd order graphs
Replies: 2
Views: 38

Re: 1st order vs 2nd order graphs

oh that makes sense, thanks
by CNourian2H
Sat Mar 14, 2020 9:58 pm
Forum: Second Order Reactions
Topic: 1st order vs 2nd order graphs
Replies: 2
Views: 38

1st order vs 2nd order graphs

can someone explain why first order graphs have a slope thats pos but 2nd order graphs have a neg slope (without using eq).
by CNourian2H
Sat Mar 14, 2020 9:57 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Endgame 15b
Replies: 5
Views: 68

Re: Endgame 15b

Oh i guess pseudo rate constant k' is just using the reactant concentration that the rate is dependent on. that would be [B].
by CNourian2H
Sat Mar 14, 2020 9:55 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Endgame 15b
Replies: 5
Views: 68

Re: Endgame 15b

Ya I dont understand how to get it directly.
by CNourian2H
Sat Mar 14, 2020 9:23 pm
Forum: Administrative Questions and Class Announcements
Topic: ENDGAME Review Session
Replies: 71
Views: 2530

Re: ENDGAME Review Session

I was just confused on 14f if anyone can explain it.
by CNourian2H
Sat Mar 14, 2020 9:23 pm
Forum: Administrative Questions and Class Announcements
Topic: ENDGAME Review Session
Replies: 71
Views: 2530

Re: ENDGAME Review Session

This was very helpful, thank you!
by CNourian2H
Sat Mar 14, 2020 9:22 pm
Forum: Administrative Questions and Class Announcements
Topic: Printing for Final
Replies: 9
Views: 160

Re: Printing for Final

He said that we submit the test online, so i dont think we even need to scan or print anything anymore
by CNourian2H
Sat Mar 14, 2020 9:21 pm
Forum: Administrative Questions and Class Announcements
Topic: Final time
Replies: 5
Views: 88

Re: Final time

Ya his email says it is. Just make sure you log on at 11:15(i think that is the time)!
by CNourian2H
Sat Mar 14, 2020 9:18 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Catalysts on Final
Replies: 6
Views: 88

Re: Catalysts on Final

can someone explain how you know something is a catalyst? im confused on that.
by CNourian2H
Sat Mar 14, 2020 9:17 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 7E.3
Replies: 2
Views: 52

Re: 7E.3

Oh that makes sense, so rate law and rate constant are proportional to each other?
by CNourian2H
Sat Mar 14, 2020 9:14 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Endgame 1a
Replies: 5
Views: 85

Re: Endgame 1a

yes, just remember that the lower concentration is always in the products.
by CNourian2H
Sat Mar 14, 2020 9:10 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Cell Diagram
Replies: 16
Views: 138

Re: Cell Diagram

I am pretty sure cathode is always on right and anode is always on left. that is how it is always shown for problems. but i guess you can make cathode on left if you make electrons flowing towards left.
by CNourian2H
Sat Mar 14, 2020 9:08 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Relationship between work, cell potential, and delta G
Replies: 6
Views: 108

Re: Relationship between work, cell potential, and delta G

When delta G is negative, there is energy free to do work. Cell potential wants to go down. IF cell potential goes down there is a release of energy free to do work. I don’t think this is a correct. In the equation delta G= -nFEcell, if cell potential is higher, and more positive, then Gibbs free e...
by CNourian2H
Sat Mar 14, 2020 9:05 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Concentration Cells
Replies: 8
Views: 87

Re: Concentration Cells

Basically, the electrons flow through the different concentrations, where it goes from a higher to a lower concentration. The lower concentration will always be for your product.
by CNourian2H
Sat Mar 14, 2020 2:08 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Test 2 on Standard Cell Potential
Replies: 6
Views: 39

Re: Test 2 on Standard Cell Potential

Ya, so since Ecell is more negative for the lithium equation, the anode is lithium equation.
by CNourian2H
Sat Mar 14, 2020 1:44 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slow and Fast Step
Replies: 7
Views: 74

Slow and Fast Step

just to clarify, the slow step determines the rate of the overall rxn by determining the reaction order?
by CNourian2H
Sat Mar 14, 2020 1:42 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: intermediates
Replies: 8
Views: 68

Re: intermediates

Think about them as something necessary to get from the reactants you want to products you want. they come along in process, but arent part of initial reactants or final products.
by CNourian2H
Sat Mar 14, 2020 1:39 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 7C.11 c)
Replies: 2
Views: 14

Re: 7C.11 c)

if you think about the rate equation...

rate= k [A]

increasing the concentration will increase the rate of the rxn as they are proportional to each other, but that does not mean it will affect k, the rate constant. also k is a constant, so it does not change over course of rxn.
by CNourian2H
Sat Mar 14, 2020 1:29 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 7E.3
Replies: 2
Views: 52

7E.3

7E.3 The presence of a catalyst provides a reaction pathway in which the activation energy of a certain reaction is reduced from 125 kJ*mol−1 to 75 kJ*mol−1. (a) By what factor does the rate of the reaction increase at 298 K, all other factors being equal? (b) By what factor would the rate change if...
by CNourian2H
Sat Mar 14, 2020 1:27 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: A- frequency factor
Replies: 2
Views: 20

A- frequency factor

can someone explain how the frequency factor comes into play with everything?
by CNourian2H
Sat Mar 14, 2020 1:26 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: determining a catalyst
Replies: 5
Views: 33

determining a catalyst

I am confused on how to determine if something is a catalyst. If you are given a reaction or multiple steps for a reaction, how do you know what the catalyst is?
by CNourian2H
Sat Mar 14, 2020 1:19 pm
Forum: Administrative Questions and Class Announcements
Topic: Final
Replies: 12
Views: 191

Re: Final

I am confused: if we are getting a time limit for this, then how does he track that we only take 3-4 hours to take the test from when he posts the test on the website.
by CNourian2H
Sat Mar 14, 2020 1:17 pm
Forum: Administrative Questions and Class Announcements
Topic: Final- general questions
Replies: 12
Views: 127

Re: Final- general questions

Do you know what time tomorrow he is going to send the test out?
by CNourian2H
Sat Mar 14, 2020 1:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Final- general questions
Replies: 12
Views: 127

Re: Final- general questions

Ya, I am not as afraid for my grade as just being prepared going into the test.
by CNourian2H
Sat Mar 14, 2020 1:15 pm
Forum: Zero Order Reactions
Topic: Equation with dt
Replies: 2
Views: 45

Re: Equation with dt

Just to add on, I never used this equation or others like this in the homework problems, so I want to know its usefulness for the final
by CNourian2H
Sat Mar 14, 2020 1:14 pm
Forum: Zero Order Reactions
Topic: Equation with dt
Replies: 2
Views: 45

Equation with dt

Im confused, do we ever actually use the equations with dt?

ex: d[A]/-[A]^2 = k dt
by CNourian2H
Sat Mar 14, 2020 1:06 pm
Forum: Administrative Questions and Class Announcements
Topic: Final- general questions
Replies: 12
Views: 127

Final- general questions

I am getting a little anxious because I do not know general details about this final. What is the exact time limit? How are we going to be tested, is it all online and are we using zoom/video recording site while taking the test? How is the test formatted? I just feel like I do not know all the info...
by CNourian2H
Wed Feb 19, 2020 9:55 pm
Forum: Administrative Questions and Class Announcements
Topic: about the Midterm...
Replies: 8
Views: 132

Re: about the Midterm...

I think my main issue was freaking out when I enter the test. Just remember to breathe and relax before starting each assessment so you can answer each question with a clear mind and right direction. Good luck everyone!
by CNourian2H
Wed Feb 19, 2020 9:53 pm
Forum: Administrative Questions and Class Announcements
Topic: Advice from a Medical Student - Part II [ENDORSED]
Replies: 150
Views: 10407

Re: Advice from a Medical Student - Part II [ENDORSED]

Thank you, this was so interesting and uplifting.
by CNourian2H
Wed Feb 19, 2020 9:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Lavelle's Office Hours
Replies: 5
Views: 96

Re: Lavelle's Office Hours

Does anyone know what Lavelle's office hours are like? Is it going over general HW problems and information, or do we need to ask him questions and bring our own HW problems in?
by CNourian2H
Wed Feb 19, 2020 9:48 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Material
Replies: 16
Views: 191

Test 2 Material

Since Test 2 has been postponed to a week later, does that mean we will also be responsible for all the info we learn next week?
by CNourian2H
Wed Feb 19, 2020 9:47 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: q=n*delta H
Replies: 5
Views: 110

Re: q=n*delta H

Whether you use delta H or C*delta T depends on the information you are given. If you have delta H reaction, for example, then you will use that value. If you don’t have that information and instead just have the material and it’s specific heat, as well as the temperature change, you will use that ...
by CNourian2H
Wed Feb 19, 2020 9:45 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Delta s = 0
Replies: 8
Views: 148

Re: Delta s = 0

that is true for reversible isothermal expansion. for an irreversible rxn, delta s is greater than 0 and delta s surroundings is =0.
by CNourian2H
Wed Feb 19, 2020 9:38 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Second law of thermodynamics
Replies: 6
Views: 101

Re: Second law of thermodynamics

it is natural for entropy to increase abd be greater than 0 because the world naturally will always has disorder. Only in conditions that aren't related to the real world, that is when entropy is =0.
by CNourian2H
Wed Feb 19, 2020 9:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Anode and Cathode
Replies: 14
Views: 315

Re: Anode and Cathode

how do the terms anode and cathode relate to oxidation and reduction. He used the latter pair of terms to define anode and cathode, but can someone explain this further?
by CNourian2H
Wed Feb 19, 2020 9:27 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1215231

Re: Post All Chemistry Jokes Here

What did the bartender say when oxygen, hydrogen, sulfur, sodium, and phosphorus walking into the bar? OH SNaP!
by CNourian2H
Wed Feb 19, 2020 9:23 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7951
Views: 1215231

Re: Post All Chemistry Jokes Here

Here is a joke:
by CNourian2H
Wed Feb 19, 2020 9:19 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Delta G and delta Gr
Replies: 3
Views: 38

Re: Delta G and delta Gr

when do we know when to write delta G r (with r as the subscript)? I see both but never understand when to write what when calculating it.
by CNourian2H
Wed Feb 19, 2020 9:17 pm
Forum: Balancing Redox Reactions
Topic: Understanding Half-Reactions
Replies: 11
Views: 86

Re: Understanding Half-Reactions

Can you explain how to tell which is being oxidized and which is being reduced in a redox rxn?
by CNourian2H
Wed Feb 19, 2020 9:15 pm
Forum: Balancing Redox Reactions
Topic: Oxidation Numbers
Replies: 7
Views: 53

Re: Oxidation Numbers

Maya Pakulski 1D wrote:What are oxidation numbers used for?


I am also partly confused with this. I understand we use the oxidation numbers for redox reactions, but can you explain how it in an example?
by CNourian2H
Wed Feb 19, 2020 9:12 pm
Forum: Balancing Redox Reactions
Topic: What is being reduced/oxidized in this rxn?
Replies: 4
Views: 41

Re: What is being reduced/oxidized in this rxn?

I think there is an error also. Yours looks correct.
by CNourian2H
Wed Feb 19, 2020 9:09 pm
Forum: Balancing Redox Reactions
Topic: Redox reactions
Replies: 2
Views: 29

Re: Redox reactions

You put the H+ for the acidic solution on the opposite side of the H20 (when applicable to add it).
by CNourian2H
Tue Feb 11, 2020 8:59 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: thermodynamically stable
Replies: 6
Views: 51

Re: thermodynamically stable

i never saw this in our notes. will we be tested on this?
by CNourian2H
Tue Feb 11, 2020 8:58 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: thermodynamically stable
Replies: 6
Views: 51

thermodynamically stable

what does it mean to b thermodynamically stable? how does this relate to gibbs free energy?
by CNourian2H
Mon Feb 10, 2020 8:58 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: higher molar entropies
Replies: 2
Views: 78

higher molar entropies

why does a monoatomic gas have higher entropy than a diatomic gas?
by CNourian2H
Mon Feb 10, 2020 4:01 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Isothermal
Replies: 9
Views: 80

Re: Isothermal

Not necessarily. Isothermal means that there is no temperature change (aka deltaT = 0) whereas reversibility has to do with entropy and if total entropy is 0 (aka in a reversible system) or if entropy of the surroundings is 0 (aka in an irreversible system). Can you explain further how entropy rela...
by CNourian2H
Mon Feb 10, 2020 3:54 pm
Forum: Calculating Work of Expansion
Topic: Reversible vs irreversible expansions
Replies: 2
Views: 33

Reversible vs irreversible expansions

What is the difference between reversible and irreversible expansions?
by CNourian2H
Sun Feb 09, 2020 10:07 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: heat cap for liquid water instead of solid water
Replies: 1
Views: 18

heat cap for liquid water instead of solid water

Why do you use the specific heat capacity for liquid water instead of solid water in this problem?
4C.11 How much heat is needed to convert 80.0 g of ice at 0.0 8C into liquid water at 20.0 8C (see Tables 4A.2 and 4C.1)?
by CNourian2H
Sun Feb 09, 2020 8:42 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: HW 4c.3
Replies: 2
Views: 39

HW 4c.3

4C.3 Calculate the final temperature and the change in enthalpy when 765 J of energy is transferred as heat to 0.820 mol Kr(g) at 298 K and 1.00 atm (a) at constant pressure; (b) at constant vol- ume. Treat the gas as ideal.

How do you differentiate what to do for constant pressure vs constant vol?
by CNourian2H
Sun Feb 09, 2020 1:01 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: HW Question
Replies: 2
Views: 34

Re: HW Question

Also, isn't it usually qsys = -qsurr
so how is this different from the problems using that equation.
by CNourian2H
Sun Feb 09, 2020 1:00 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: HW Question
Replies: 2
Views: 34

HW Question

Hi. Im confused why we would add the heat of kettle and heat of water together for this problem in (a). 4A.7 (a) Calculate the heat that must be supplied to a copper kettle of mass 400.0 g containing 300.0 g of water to raise its tem- perature from 20.0 8C to the boiling point of water, 100.0 8C. (b...
by CNourian2H
Thu Jan 23, 2020 2:18 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acids and Bases pka and pkb
Replies: 8
Views: 58

Re: Acids and Bases pka and pkb

Mariah wrote:
Abhi Vempati 2H wrote:Adding on to what @Hui Qiao Wu 1I mentioned, the lower the pka of an acid, the higher the pKb of its conjugate base. This is because of the equation pka + pKb = 14. Hope this helps!


14 is the same as p[sub]w right?


Yes, Pkw=14
by CNourian2H
Wed Jan 22, 2020 3:56 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Acids and Bases pka and pkb
Replies: 8
Views: 58

Acids and Bases pka and pkb

Can someone explain the relation btwn pkA/pkB and how strong the acid/base is. If I have a higher pkB, does that mean I have a weaker base?
by CNourian2H
Wed Jan 22, 2020 1:36 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: 5J.13
Replies: 5
Views: 115

5J.13

5J.13 A gaseous mixture consisting of 2.23 mmol N2 and 6.69 mmol H2 in a 500.-mL container was heated to 600. K and allowed to reach equilibrium. Will more ammonia be formed if that equilibrium mixture is then heated to 700. K? For N2(g) + 3H2(g) --> 2NH3(g), K=1.7 x 10^-3 at 600.K and K=7.8 x 10^-5...
by CNourian2H
Tue Jan 21, 2020 6:08 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: partial pressure
Replies: 5
Views: 41

partial pressure

what are the general units for partial pressure? I have seen bar and atm, so do both work depending on what the problem gives you?
by CNourian2H
Tue Jan 21, 2020 5:13 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G part c
Replies: 3
Views: 33

5G part c

5G.1 State whether the following statements are true or false. If false, explain why.
(c) If one starts with a higher pressure of reactant, the equilibrium constant will be larger.

Can someone explain C to me? I understand it is false but i want to know the best way to explain it.
by CNourian2H
Wed Jan 15, 2020 6:26 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: HW 5J.5 part C
Replies: 3
Views: 42

HW 5J.5 part C

5J.5 State whether reactants or products will be favored by an increase in the total pressure (resulting from compression) on each of the following equilibria. If there is no change, explain why that is so. 
(c) 4NH3(g)+ 5O2(g) -> HNO(g) + 6H2O(g) How do I know the reactants are favored in this case...
by CNourian2H
Sun Dec 08, 2019 3:40 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid Strength- Acetic vs Formic Acid
Replies: 4
Views: 181

Re: Acid Strength- Acetic vs Formic Acid

So it is involving electronegativity...Im guessing.
by CNourian2H
Sun Dec 08, 2019 3:39 am
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid Strength- Acetic vs Formic Acid
Replies: 4
Views: 181

Re: Acid Strength- Acetic vs Formic Acid

Oh I think I got it. It's because of the CH3 in acetic acid is electron donating, and it contributes e- density towards the O-H bond making the bond stronger to break and H+ ion less wanting to go and attach to another compound.
by CNourian2H
Sun Dec 08, 2019 3:36 am
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Rod vs spherical shaped molecules
Replies: 8
Views: 168

Re: Rod vs spherical shaped molecules

I get it now. The rod shaped molecs have greater surface area bc of more pts of interaction btwn 2 polar molecs, which causes a stronger interaction btwn the 2 molecs. therefore, a higher BP would be needed to break up the 2 molecs.
by CNourian2H
Sat Dec 07, 2019 10:05 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4662

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

Naren_Ramesh_4D wrote:On question 2b of the mini marshmallow, does the order of the ligand in the coordination complex matter?


I dont think so

order of ligands matters in writing the name- alphabetical order
not in writing formula
by CNourian2H
Sat Dec 07, 2019 1:40 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: HW 6D.11 part e
Replies: 1
Views: 79

HW 6D.11 part e

6D.11 Decide whether an aqueous solution of each of the following salts has a pH equal to, greater than, or less than 7. If pH . 7 or pH , 7, write a chemical equation to justify your answer. (e) AlCl3;

I am confused how to write the equation for Al +3. Why does it combine with H20 first?
by CNourian2H
Fri Dec 06, 2019 6:04 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Acid Strength- Acetic vs Formic Acid
Replies: 4
Views: 181

Acid Strength- Acetic vs Formic Acid

Problem 6C.21b: Why is formic acid stronger than acetic acid? I'm confused with the electronegativity/polarity aspect of it.
by CNourian2H
Fri Dec 06, 2019 5:13 pm
Forum: Lewis Acids & Bases
Topic: List of Strong Acids/Bases
Replies: 1
Views: 27

Re: List of Strong Acids/Bases

Also, if anyone knows the full list of strong and weak acids and bases we need to memorize.
by CNourian2H
Fri Dec 06, 2019 5:12 pm
Forum: Lewis Acids & Bases
Topic: List of Strong Acids/Bases
Replies: 1
Views: 27

List of Strong Acids/Bases

Does anyone have a good list that simply puts what to look for when trying to decide whether one acid/base is stronger than another?
by CNourian2H
Thu Dec 05, 2019 10:31 pm
Forum: Amphoteric Compounds
Topic: Transition Metals
Replies: 1
Views: 91

Transition Metals

How do i know if a transition metal is amphoteric? Do we need to know specific ones for the final?
by CNourian2H
Wed Dec 04, 2019 9:50 pm
Forum: Naming
Topic: HW Problem 9C 3d
Replies: 1
Views: 40

HW Problem 9C 3d

We are asked to write the formula for sodiumbisoxalato(diaqua)ferrate(III)

I'm confused how we know which ligand to put first and which to put second in the formula for the compound.
Also, why is diaqua in parentheses?
by CNourian2H
Wed Dec 04, 2019 9:22 pm
Forum: Naming
Topic: Homework Problem 9C 3a
Replies: 2
Views: 49

Homework Problem 9C 3a

So the problem asks to write the formula for potassium hexacyanidochromate(III) I understand how to get the formula from this coordination compound name but I want to clarify a few things. 1)the -3 charge for hexacyanidochromate is not written outside the brackets bc it cancels out with the +3 charg...
by CNourian2H
Wed Dec 04, 2019 3:39 pm
Forum: Hybridization
Topic: Hybridization General Question
Replies: 3
Views: 52

Hybridization General Question

In Homework question 2.45, it asks to write the hybridization of each lone pair in the bonding in H2C =(double bond) CHCHO. The drawing in the answer key says the lone pairs of O have a hybridization of sp2 but the hybridization of O when its bonded is 2sp2 (difference is the 2 in front). What does ...
by CNourian2H
Wed Dec 04, 2019 2:25 pm
Forum: Hybridization
Topic: Drawing Acrylonitrile
Replies: 1
Views: 32

Drawing Acrylonitrile

Problem 2F.13 asks to draw Acrylonitrile, which is CH2CHCN, and then state the bond angles. How do I know which element is the central atom and how to organize the surrounding molecules? The drawing affects what bond angles I put, so is there a way to ensure I draw it correctly with all compounds si...
by CNourian2H
Thu Nov 21, 2019 5:02 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: Hydrogen Bonding Homework Problem
Replies: 2
Views: 43

Hydrogen Bonding Homework Problem

3F.5 Suggest, giving reasons, which substance in each of the fol- lowing pairs is likely to have the higher normal melting point (Lewis structures may help your arguments): (a) HCl or NaCl; (b) C2H5OC2H5 (diethyl ether) or C4H9OH (butanol); (c) CHI3 or CHF3; (d) C2H4 or CH3OH. In B, why can buthanol...
by CNourian2H
Wed Nov 13, 2019 9:35 pm
Forum: Administrative Questions and Class Announcements
Topic: Test #2
Replies: 22
Views: 2110

Re: Test #2

Do you think it will also have some information from the midterm as well? Or only new untested topics?
by CNourian2H
Tue Nov 12, 2019 1:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Test #2
Replies: 22
Views: 2110

Re: Test #2

Maybe we should ask Dr. Lavelle on Wednesday during the lecture, the test is coming up and I want to start preparing for it.
by CNourian2H
Tue Nov 12, 2019 1:41 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 7 Homework
Replies: 7
Views: 88

Re: Week 7 Homework

I feel like the homework is pretty flexible in which concepts you can do it on that are relatively recent- I'm thinking concepts like dipole moments, intermolecular and intramolecular forces, and whatever is around that is all ok.
by CNourian2H
Tue Nov 12, 2019 1:37 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Grades
Replies: 3
Views: 61

Re: Midterm Grades

Hiba Alnajjar_4B wrote:Not sure when they'll be posted, but Dr. Lavelle announced that we would be getting them back during Wednesday lecture, so maybe after Wednesday?


Are we reviewing the questions on the midterm during the lecture or just getting them back?
by CNourian2H
Tue Nov 12, 2019 1:35 pm
Forum: Dipole Moments
Topic: Temporary Dipoles
Replies: 5
Views: 70

Temporary Dipoles

Can someone explain what a temporary dipole is and how it occurs? How does it happen on a nonpolar molecule?
by CNourian2H
Tue Nov 12, 2019 1:32 pm
Forum: DeBroglie Equation
Topic: When to Use
Replies: 8
Views: 164

When to Use

I know the De Brogile Equation is used in certain circumstances, what are those? How do you know based on the wording of the question that you need to use this equation for your answer?
by CNourian2H
Tue Nov 12, 2019 1:30 pm
Forum: Lewis Structures
Topic: Exceptions
Replies: 5
Views: 64

Exceptions

What elements have exceptions to the octet rule other than the ones that are past the 3rd period and can have more than an octet? I know there are specific elements that also like specific types of bonds, what are those elements?
by CNourian2H
Tue Nov 12, 2019 1:27 pm
Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
Topic: Rod vs spherical shaped molecules
Replies: 8
Views: 168

Rod vs spherical shaped molecules

Can someone explain the key differences between rod shaped and spherical shaped molecules?
by CNourian2H
Tue Nov 12, 2019 1:07 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Wavelength Plausibility
Replies: 30
Views: 1321

Re: Wavelength Plausibility

Technically, if the question asks if the wavelength is detectable, or more often it will ask if there are "detectable wavelike properties" that means that it wants to know whether the wavelength is greater than 10e-15 or not. That makes a lot of sense! A good thing to look out for, thanks!
by CNourian2H
Tue Nov 12, 2019 1:05 pm
Forum: Administrative Questions and Class Announcements
Topic: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE
Replies: 53
Views: 3130

Re: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE

All these worksheets were really helpful for reviewing for the midterm, thank you! Will any worksheets be posted to review for the upcoming Test 2? Thanks!
by CNourian2H
Tue Nov 12, 2019 1:02 pm
Forum: Student Social/Study Group
Topic: Chemistry News
Replies: 65
Views: 48123

Re: Chemistry News

Wow! I just read some of these articles and they're so interesting! Thank you for sharing, keep them coming!
by CNourian2H
Tue Nov 12, 2019 1:00 pm
Forum: Administrative Questions and Class Announcements
Topic: Extra Credit?
Replies: 6
Views: 105

Topics on Test 2

Hey guys! Does anyone know the full range of topics covered on Test 2? I know it is coming up next week starting the 19th but I am unsure what exactly is on it.
by CNourian2H
Tue Nov 12, 2019 12:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Extra Credit?
Replies: 6
Views: 105

Extra Credit?

I'm pretty sure Dr. Lavelle doesn't offer any extra credit or other opportunities to boost up your grade, but I just wanted to make sure on Chem Community. Thanks!
by CNourian2H
Tue Nov 12, 2019 12:57 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 2 Review Sessions?
Replies: 6
Views: 97

Test 2 Review Sessions?

Are there any review sessions and workshops available for the upcoming Test 2? Really nervous and wanted to get extra practice.
by CNourian2H
Tue Nov 12, 2019 12:56 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Grades
Replies: 3
Views: 61

Midterm Grades

Does anyone know when our midterm grades will be posted onto myucla?
by CNourian2H
Tue Nov 12, 2019 12:52 pm
Forum: Quantum Numbers and The H-Atom
Topic: Finding orbitals without given ml quantum number
Replies: 2
Views: 97

Finding orbitals without given ml quantum number

1D.23 How many orbitals can have the following quantum numbers in an atom: (a) n=2, l=1; (c) n=2?

I am confused with how to answer a and c because they don't give a mI value so there are multiple orbitals that can have those quantum numbers.
by CNourian2H
Tue Nov 12, 2019 12:43 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Writing full electron configuration
Replies: 3
Views: 117

Writing full electron configuration

If it says to write the full electron configuration in the ground state for an element, do you ever need to include the different subshells that show unpaired electrons? for example: for the full electron configuration of nitrogen, in the 2p-orbital do you write it out as [2px1 2py1 2pz1] or just [2...
by CNourian2H
Tue Nov 12, 2019 12:38 pm
Forum: Empirical & Molecular Formulas
Topic: Answering a Question without amount of elements
Replies: 1
Views: 123

Answering a Question without amount of elements

When you don't get the amount in grams of each element in the question, what is the best way to find out those amounts? You would get the molar mass of the compound and the amounts of the other molecules in the equation. There was a question like this on the midterm.
by CNourian2H
Tue Nov 12, 2019 12:35 pm
Forum: Administrative Questions and Class Announcements
Topic: Final Studying
Replies: 14
Views: 166

Final Studying

Has anyone began reviewing for the final? If so, what are you doing to slowly prepare?
by CNourian2H
Sun Oct 20, 2019 9:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quick Question about orbitals
Replies: 1
Views: 53

Quick Question about orbitals

Quick question! Why does the # of orbitals increase by 2 per level? For example, why does S have 1 orbital and the next level, p, has 3 orbitals, d has 5 orbitals, etc? It increases by 2, why can't it increase by 1?
by CNourian2H
Sun Oct 20, 2019 9:09 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Spin up and Spin down
Replies: 2
Views: 29

Spin up and Spin down

I am really confused with the spin up and spin down aspect we discussed in class. Can someone clear it up for me?
I also remember him saying that when both electrons are spin up, they interact differently than when they are spin down. Why?
by CNourian2H
Sun Oct 20, 2019 9:06 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Neon- electron configuration
Replies: 3
Views: 33

Neon- electron configuration

In class, Dr. Lavelle said that elements like Neon are not good at building bonds. Why is this so?
by CNourian2H
Sun Oct 20, 2019 8:56 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Series
Replies: 3
Views: 47

Re: Series

The series is from the spectrum of hydrogen, as sequences of lines correspond to atomic transitions that each begin or end with the same atomic state in hydrogen. The Balmer series- all of the lines are in the visible region The Lyman series- ultraviolet region The Brackett series, Pfund series, Pas...
by CNourian2H
Sun Oct 20, 2019 8:32 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Friday's lecture (4s and 3d)
Replies: 3
Views: 53

Re: Friday's lecture (4s and 3d)

The 4s sublevel is filled before the 3d sublevel because the 4s subshell is lower in energy, and it is farther from the nucleus than the 3d subshell.
by CNourian2H
Sun Oct 13, 2019 7:23 pm
Forum: Photoelectric Effect
Topic: Electrons ejected based on wavelength
Replies: 3
Views: 59

Electrons ejected based on wavelength

I am confused why light sources with long wavelengths of light cannot eject electrons in the photoelectric experiment, but why light sources with short wavelengths can. Can someone clear this up for me?
by CNourian2H
Sun Oct 13, 2019 7:19 pm
Forum: Properties of Electrons
Topic: Wavelike vs Particle-like Behavior
Replies: 6
Views: 70

Re: Wavelike vs Particle-like Behavior

I thought of this to mean that electrons behave both like particles and like waves. De Brogile explains that all material particles in motion have wave characteristics, but for microscopic bodies like electrons this observation is important. Electrons are under high speed, showing a wave-like appear...
by CNourian2H
Sun Oct 13, 2019 6:57 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Textbook Problem- 1B.19
Replies: 1
Views: 25

Textbook Problem- 1B.19

Hi guys, I'm confused with this textbook problem. Can anyone describe the steps needed to complete the problem? 1B.19 Protons and neutrons have nearly the same mass. How different are their wavelengths? Calculate the wavelength of each particle when traveling at 2.75 x 10^5 mxs^-1 in a particle acce...
by CNourian2H
Sun Oct 13, 2019 6:51 pm
Forum: Properties of Light
Topic: Quanta
Replies: 4
Views: 70

Re: Quanta

We use quantum mechanics to describe the behavior of very small objects that can accept energy only in discrete amounts. These discrete amounts are called quanta. It's easy for me to think about quanta as the smallest unit of any physical property- whether that is energy, matter, etc. It is like a p...

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