Search found 104 matches

by AKhanna_3H
Sat Mar 14, 2020 11:59 am
Forum: Administrative Questions and Class Announcements
Topic: Format?
Replies: 11
Views: 104

Re: Format?

Jared Khoo 1G wrote:Will the final still account for the 180 points on the syllabus or will it be worth less?

He said in an email that it is still 180 points but it will be short.
by AKhanna_3H
Fri Mar 13, 2020 8:44 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 6.45
Replies: 3
Views: 19

6.45

For this question how can you tell which metals are the most strongly reducing?
by AKhanna_3H
Fri Mar 13, 2020 6:15 am
Forum: Administrative Questions and Class Announcements
Topic: Partial Credit
Replies: 8
Views: 93

Partial Credit

Will we be able to get partial credit for answers on the final if it is electronic?
by AKhanna_3H
Thu Mar 12, 2020 1:24 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: 7.23 part b
Replies: 1
Views: 18

7.23 part b

Could someone explain part b of this question? I understand that the slow step of the reaction determines the rate but how do you replace the intermediate in the rate law using the other steps in the mechanism?
by AKhanna_3H
Thu Mar 12, 2020 9:43 am
Forum: Student Social/Study Group
Topic: discussion
Replies: 3
Views: 48

Re: discussion

I think they are cancelled but we still need to email our TA our week 10 homework.
by AKhanna_3H
Thu Mar 12, 2020 9:40 am
Forum: Administrative Questions and Class Announcements
Topic: Format?
Replies: 11
Views: 104

Re: Format?

Mariah wrote:
Rosa Munoz 2E wrote:No idea. We're all waiting on Lavelle's email


We won't have to be on campus right?


Since it's a take home test we most likely won't have to be on campus, just need access to wifi.
by AKhanna_3H
Thu Mar 12, 2020 7:50 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: final
Replies: 3
Views: 47

Re: final

The questions on the 14A final were fairly even in terms of material from the whole quarter, so I would assume it will be the same for 14B.
by AKhanna_3H
Tue Mar 10, 2020 9:57 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Effect of temperature 7D.7
Replies: 3
Views: 34

Effect of temperature 7D.7

For part c of this question, it asks what the effect of raising the temperature on the rate constants. What are the general trends of raising the temperature for endothermic and exothermic reactions?
by AKhanna_3H
Sun Mar 08, 2020 2:38 pm
Forum: General Science Questions
Topic: Review Packet
Replies: 14
Views: 120

Re: Review Packet

I think there will be an announcement in class tomorrow if you are referring to Lyndon's review packet
by AKhanna_3H
Sun Mar 08, 2020 2:37 pm
Forum: First Order Reactions
Topic: Graph
Replies: 9
Views: 69

Re: Graph

The graph will be linear with a slope of -k
by AKhanna_3H
Sun Mar 08, 2020 2:37 pm
Forum: First Order Reactions
Topic: order of reaction equations
Replies: 6
Views: 67

Re: order of reaction equations

I do not believe that we will need to know the derivations. I would only think that we would need to if it is explicitly stated on the outline sheets.
by AKhanna_3H
Wed Mar 04, 2020 12:22 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Possible Solution Error on 6N.1 part b
Replies: 5
Views: 69

Re: Possible Solution Error on 6N.1 part b

My TA confirmed that it is an error in the solution manual because there should only be 1 e-, so your answer is correct!
by AKhanna_3H
Tue Mar 03, 2020 6:35 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Including Inert Electrodes
Replies: 2
Views: 25

Including Inert Electrodes

When do we include these in a cell diagram?
by AKhanna_3H
Sun Mar 01, 2020 8:13 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: test 2 topics
Replies: 11
Views: 59

Re: test 2 topics

The second page of outline 4 and all of outline 5. I usually do all of the practice problems on the outlines to prepare for the tests and I find that every topic is covered.
by AKhanna_3H
Sun Mar 01, 2020 8:09 pm
Forum: Balancing Redox Reactions
Topic: Anode and Cathode
Replies: 8
Views: 52

Re: Anode and Cathode

If not told, you can figure out which is which by calculating what would make the overall cell potential positive. You could find the individual cell potentials for each half reaction, and then determine which would make E(cathode) - E(anode) a positive value.
by AKhanna_3H
Sun Mar 01, 2020 8:08 pm
Forum: Balancing Redox Reactions
Topic: OH and H
Replies: 8
Views: 52

Re: OH and H

They can be on either side, the equation just needs to be balanced
by AKhanna_3H
Sun Mar 01, 2020 8:04 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 19
Views: 150

Re: Test 2

Test 2 will only cover the second page of outline 4 and all of outline 5.
by AKhanna_3H
Thu Feb 27, 2020 3:36 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 6N.9
Replies: 1
Views: 38

Re: 6N.9

I'm not sure if you can use this logic with every problem, but I think you would determine which is which by calculating what would make the overall cell potential positive. So you could find the individual cell potentials for each half reaction, and then determine which would make E(cathode) - E(an...
by AKhanna_3H
Sun Feb 23, 2020 10:23 pm
Forum: Van't Hoff Equation
Topic: Thermo in Test 2
Replies: 6
Views: 60

Re: Thermo in Test 2

Whatever was not covered on the midterm, so the second page of outline 4
by AKhanna_3H
Sun Feb 23, 2020 10:20 pm
Forum: Balancing Redox Reactions
Topic: Oxidation?
Replies: 10
Views: 57

Re: Oxidation?

Oxidation is the loss of electrons, so the oxidation number increases. Reduction is the gain of electrons, so the oxidation number decreases.
by AKhanna_3H
Sun Feb 23, 2020 10:17 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Test 2
Replies: 13
Views: 81

Re: Test 2

The second page of outline 4 and all of outline 5
by AKhanna_3H
Sun Feb 23, 2020 10:13 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: STP
Replies: 13
Views: 82

Re: STP

Assume pressure is 1 atm and temperature is 273 K
by AKhanna_3H
Wed Feb 19, 2020 1:06 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: 5.55
Replies: 4
Views: 63

Re: 5.55

Solids and liquids are not included in equilibrium constants. Only gases and aqueous solutions are included.
by AKhanna_3H
Fri Feb 14, 2020 2:08 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: K and Q and G
Replies: 6
Views: 55

Re: K and Q and G

If the system is at equilibrium, you can replace Q with K in the equation.
by AKhanna_3H
Fri Feb 14, 2020 2:06 pm
Forum: Ideal Gases
Topic: pv=nrt
Replies: 19
Views: 142

Re: pv=nrt

Yes, this equation can be used for STP.
by AKhanna_3H
Fri Feb 14, 2020 2:05 pm
Forum: Phase Changes & Related Calculations
Topic: Equation Choice
Replies: 5
Views: 74

Re: Equation Choice

A phase change is when something goes from a solid to liquid (fusion), liquid to gas (vaporization), solid to gas (sublimation), or the reverse of these. In terms of equations to use, I assume you are talking about finding the q value, or amount of heat, associated for that phase change. In this cas...
by AKhanna_3H
Fri Feb 14, 2020 2:00 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K
Replies: 12
Views: 86

Re: K

Only include gases and aqueous solutions. Disregard solids and liquids.
by AKhanna_3H
Wed Feb 12, 2020 1:26 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 4F.11
Replies: 1
Views: 29

4F.11

For this problem, the solutions manual uses delta S = nRlnT2/T1 to solve for change of entropy. Why do they use this formula, because I thought the formula was nClnT2/T1, and C would be 5/2R since it is constant pressure?
by AKhanna_3H
Sun Feb 09, 2020 7:44 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: Difference between qv and qp
Replies: 5
Views: 50

Re: Difference between qv and qp

In general the subscripts are just indicating volume and pressure. This is similar to saying Cv and Cp as heat capacities at constant volume and constant pressure.
by AKhanna_3H
Sun Feb 09, 2020 7:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Pressure change
Replies: 3
Views: 25

Re: Pressure change

Additionally, if the pressure increases the reaction will shift towards the side of the equation with less moles to counteract the change. If the pressure decreases the reaction will shift towards the side of the equation with more moles.
by AKhanna_3H
Sun Feb 09, 2020 7:35 pm
Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
Topic: 4G.5
Replies: 4
Views: 30

4G.5

How would you explain why the cis crystal would have a higher entropy than the trans isomer? Also what does residual entropy mean and is it different than entropy? Thank you!
by AKhanna_3H
Thu Feb 06, 2020 6:30 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 4D.9
Replies: 1
Views: 40

Re: 4D.9

I had the same question, but I found the answer in an endorsed post from Dr. Lavelle, if you scroll up to the announcements of this section it should be there.
by AKhanna_3H
Tue Feb 04, 2020 9:52 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Bomb Calorimeters
Replies: 2
Views: 24

Bomb Calorimeters

What exactly do we need to know about bomb calorimeters? Is there a specific formula/concept that corresponds to using a bomb calorimeter?
by AKhanna_3H
Thu Jan 30, 2020 1:35 pm
Forum: Phase Changes & Related Calculations
Topic: Molar Heat Capacity at Cp s. Cv
Replies: 4
Views: 36

Re: Molar Heat Capacity at Cp s. Cv

Subscript p refers to constant pressure and subscript v refers to constant volume.
by AKhanna_3H
Thu Jan 30, 2020 1:33 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 4a.9
Replies: 3
Views: 20

Re: 4a.9

This question would use the heat capacity formula q = nCdeltaT. You would solve for q of copper and q of water by setting them equal to each other and assigning a negative sign to the q of water (calorimeter). You can set them equal to each other because the heat lost by one reaction is gained by th...
by AKhanna_3H
Thu Jan 30, 2020 1:24 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Delta X and U
Replies: 1
Views: 21

Re: Delta X and U

I think the book is just using it as an example of any variable to show that delta means "change of." X is a placeholder for other variables such as U.
On page 244 of the textbook it says the symbol delta X means a difference in the property X.
by AKhanna_3H
Thu Jan 30, 2020 1:15 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Internal energy change, isothermal expansion
Replies: 1
Views: 13

Re: Internal energy change, isothermal expansion

I believe it is because we are assuming an ideal gas, in which there are no intermolecular forces, so we only consider kinetic energy.
by AKhanna_3H
Wed Jan 29, 2020 10:46 pm
Forum: Phase Changes & Related Calculations
Topic: internal energy
Replies: 11
Views: 75

Re: internal energy

Internal energy is represented by delta U. Q represents the heat entering or exiting the system.
by AKhanna_3H
Sun Jan 26, 2020 12:12 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: different methods
Replies: 3
Views: 24

Re: different methods

I believe it usually depends on the information given. For example, if you are given the bond enthalpies then it would be best to use that method versus a different one.
by AKhanna_3H
Sun Jan 26, 2020 12:11 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: state functions
Replies: 4
Views: 19

Re: state functions

State functions can be added or subtracted because it does not matter what path it took to get from the initial value to the final value.
by AKhanna_3H
Thu Jan 23, 2020 9:22 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Changes in Pressure
Replies: 9
Views: 59

Changes in Pressure

How does increasing the pressure affect the reaction? Are reactants or products favored?
by AKhanna_3H
Thu Jan 23, 2020 4:04 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: pKa to Kb
Replies: 12
Views: 75

Re: pKa to Kb

pKa + pKb = pKw. Therefore pKa + pKb = 14. 14 - pKb = pKa, and 14 - pKa = pKb.
by AKhanna_3H
Thu Jan 23, 2020 1:41 pm
Forum: Ideal Gases
Topic: test 1
Replies: 9
Views: 75

Re: test 1

No, test 1 will cover up to last Friday's lecture (1/17).
by AKhanna_3H
Sat Jan 18, 2020 11:02 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Tips for Test
Replies: 23
Views: 176

Re: Tips for Test

Last quarter for 14A with Lavelle, I did all the practice problems on the syllabus for the topics we would be tested on and I found that to be very helpful!
by AKhanna_3H
Sat Jan 18, 2020 11:00 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Change in Pressure
Replies: 5
Views: 42

Re: Change in Pressure

If more reactants are added (increasing the number of moles), the reaction will "shift right" meaning more products will be formed to offset that change. Now that there are more reactants available, more products must form to keep the reaction in equilibrium. If reactants are removed (decr...
by AKhanna_3H
Sat Jan 18, 2020 10:57 am
Forum: Administrative Questions and Class Announcements
Topic: Study Guide Test One
Replies: 17
Views: 128

Re: Study Guide Test One

There's no study guide, but for 14A with Dr. Lavelle I found it was very helpful to do all the practice problems on the syllabus for the sections we would be tested on. For test 1 I believe those are the first two sections.
by AKhanna_3H
Sat Jan 18, 2020 10:55 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Difference between K and Q?
Replies: 11
Views: 56

Re: Difference between K and Q?

Q and K are both measured by the ratio of products over reactants, but K represents that ratio at equilibrium while Q can represent that ratio at any point in the reaction.
by AKhanna_3H
Sat Jan 18, 2020 10:54 am
Forum: Administrative Questions and Class Announcements
Topic: How was my Friday class/lecture?
Replies: 4
Views: 58

Re: How was my Friday class/lecture?

I really appreciated that there were a lot of examples and we went through each in detail.
by AKhanna_3H
Sun Jan 12, 2020 3:54 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 1 date
Replies: 4
Views: 37

Re: Test 1 date

During your week 3 discussion
by AKhanna_3H
Sun Jan 12, 2020 3:49 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: What is this?
Replies: 23
Views: 379

Re: What is this?

Le Chatelier's Principle explains how chemical reactions shift to minimize the effects of a change. For example, if more reactants are added, the reaction will shift "right" and more product is formed. If reactants are removed, the reaction will shift "left" and less products wil...
by AKhanna_3H
Sun Jan 12, 2020 3:46 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: When to use Kc vs Kp
Replies: 7
Views: 39

Re: When to use Kc vs Kp

Kc refers to concentrations and Kp refers to pressure, so (aq) would correlate to Kc and (g) to Kp
by AKhanna_3H
Sun Jan 12, 2020 3:40 pm
Forum: Administrative Questions and Class Announcements
Topic: 14A Final Pickup
Replies: 5
Views: 55

14A Final Pickup

What room can we pick up our 14A finals from? And can we start getting them this week or next week?
by AKhanna_3H
Tue Jan 07, 2020 3:40 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework 1
Replies: 18
Views: 189

Homework 1

When is the first homework assignment due? I know they are usually due in discussion sections but is that also true for week 1?
by AKhanna_3H
Sat Dec 07, 2019 2:53 pm
Forum: General Science Questions
Topic: Final Content
Replies: 3
Views: 89

Re: Final Content

Yes the material is cumulative but will focus on material after the midterm.
by AKhanna_3H
Sat Dec 07, 2019 9:58 am
Forum: Lewis Acids & Bases
Topic: 6A.17
Replies: 1
Views: 23

6A.17

This question asks whether the following oxides are acidic, basic, or amphoteric: a. BaO b. SO3 c. As2O3 d. Bi2O3
I understand the definitions of acids, bases, and what it means to be amphoteric, but how do you know what each oxide is?
by AKhanna_3H
Fri Dec 06, 2019 3:58 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: AX4 geometry in coordination comppounds
Replies: 2
Views: 38

Re: AX4 geometry in coordination comppounds

AX4 is for tetrahedral molecules. Square planar molecules have four bonding regions and two sets of lone pairs, or AX4E2.
by AKhanna_3H
Wed Dec 04, 2019 12:08 am
Forum: Naming
Topic: naming email
Replies: 2
Views: 56

Re: naming email

What email is it? Is there anyway you can send a screenshot because I cannot find that email
by AKhanna_3H
Tue Dec 03, 2019 8:19 pm
Forum: Naming
Topic: Memorizing
Replies: 9
Views: 84

Re: Memorizing

Does someone have a screenshot of the table he sent us I can't seem to find it in my email? Thanks!
by AKhanna_3H
Tue Dec 03, 2019 12:17 pm
Forum: General Science Questions
Topic: Exam Subjects
Replies: 5
Views: 147

Re: Exam Subjects

I believe the exam is cumulative but will emphasize topics after the midterm.
by AKhanna_3H
Mon Dec 02, 2019 11:30 pm
Forum: General Science Questions
Topic: Final test locations
Replies: 4
Views: 83

Re: Final test locations

These are the room assignments he posted on his website, hope this helps!
by AKhanna_3H
Mon Dec 02, 2019 11:27 pm
Forum: Administrative Questions and Class Announcements
Topic: Marshmallow
Replies: 1
Views: 78

Re: Marshmallow

After the review session on Friday!
by AKhanna_3H
Mon Dec 02, 2019 11:18 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 9 and 10 Homework
Replies: 2
Views: 47

Re: Week 9 and 10 Homework

I think anything from the coordination compounds and acid and base structures on the syllabus should be ok!
by AKhanna_3H
Mon Dec 02, 2019 11:15 pm
Forum: Naming
Topic: Hw 9c.1 part c
Replies: 5
Views: 54

Re: Hw 9c.1 part c

The formula gives us (OH2) which indicates aqua, if it was (OH), that would be hydroxido
by AKhanna_3H
Mon Dec 02, 2019 10:06 pm
Forum: Administrative Questions and Class Announcements
Topic: Grades
Replies: 15
Views: 177

Re: Grades

Besides the 50% required to get a C-, Dr. Lavelle does not determine the grade cutoffs for an A, A-, B+, etc. until after the final, meaning you may not have to get the standard 93% to get an A in the class. It all depends on the overall scores at the end.
by AKhanna_3H
Mon Dec 02, 2019 4:06 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration
Replies: 4
Views: 101

Re: Electron Configuration

Dr. Lavelle explained that the configurations should be written in order of energy level, so 3d would come before 4s.
by AKhanna_3H
Mon Dec 02, 2019 4:03 pm
Forum: Hybridization
Topic: Lone Pairs
Replies: 2
Views: 30

Re: Lone Pairs

Since lone pairs count as a region of electron density, I believe they would count towards hybridization. For example, in a water molecule, the oxygen has two lone pairs and two covalent bonds, and would have a hybridization of sp3.
by AKhanna_3H
Mon Dec 02, 2019 3:59 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: seesaw
Replies: 4
Views: 57

Re: seesaw

Dr. Lavelle said in a previous post that the seesaw is a topic covered in 14B and we do not need to explicitly know this for the final.
by AKhanna_3H
Mon Dec 02, 2019 3:57 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Pka
Replies: 2
Views: 30

Re: Pka

large Ka/small pKa = strong acid
small Ka/large pKa = weak acid
by AKhanna_3H
Mon Dec 02, 2019 3:51 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: how to find pH
Replies: 4
Views: 44

Re: how to find pH

According to a previous post, Dr. Lavelle said that we would not have to calculate one from the other, but it is important to know that when you put an acid in a solution with a pKa less than the pH of the solution the acid will dissociate.
by AKhanna_3H
Mon Dec 02, 2019 3:48 pm
Forum: Lewis Structures
Topic: 2D.3
Replies: 2
Views: 65

Re: 2D.3

Ba and Br have the highest difference in electronegativity according to periodic table trends, therefore the bonds in BaBr2 are primarily ionic
by AKhanna_3H
Tue Nov 19, 2019 11:19 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 bond
Replies: 3
Views: 34

Re: hydrogen bond

Hydrogen bonds form because hydrogen has a partially positive charge, and hydrogen atoms form hydrogen bonds with extremely electronegative atoms with partially negative charges. These atoms are Fluorine, Oxygen, and Nitrogen.
by AKhanna_3H
Wed Nov 13, 2019 2:16 pm
Forum: Administrative Questions and Class Announcements
Topic: Regrade requests
Replies: 3
Views: 92

Regrade requests

If I went through the solutions and feel as if I should have received points that I did not get, is there a way to do a regrade request?
by AKhanna_3H
Wed Nov 13, 2019 1:36 pm
Forum: Administrative Questions and Class Announcements
Topic: Class grading
Replies: 12
Views: 225

Re: Class grading

Final grades are not assigned until the end of the quarter once the averages are determined. Just try to get as many points as possible throughout the course.
by AKhanna_3H
Thu Nov 07, 2019 11:12 am
Forum: Bond Lengths & Energies
Topic: Test 2 Topics
Replies: 40
Views: 498

Re: Test 2 Topics

Material after the midterm to what we have learned just before the test
by AKhanna_3H
Thu Nov 07, 2019 11:11 am
Forum: Student Social/Study Group
Topic: Class Grading
Replies: 44
Views: 1047

Re: Class Grading

The class is not curved and letter grades are not assigned to tests and midterms. At the end of the quarter Dr. Lavelle will create the cutoffs for A/A-/B+ etc. depending on what the end points are. This means that to get an A in the class you may have to get a different percentage than the standard...
by AKhanna_3H
Thu Nov 07, 2019 11:07 am
Forum: Balancing Chemical Reactions
Topic: Balancing This Equation
Replies: 11
Views: 170

Re: Balancing This Equation

Combustion reactions always have O2 as a reactant and H20 and C02 as products.
by AKhanna_3H
Thu Nov 07, 2019 11:03 am
Forum: Octet Exceptions
Topic: Why can't Aluminum have an expanded octet?
Replies: 5
Views: 106

Re: Why can't Aluminum have an expanded octet?

Aluminum does not have an expanded octet. Since it is a group 3 atom it sometimes violates the octet rule by having less than 8 valence electrons when bonded.
by AKhanna_3H
Thu Nov 07, 2019 10:43 am
Forum: Lewis Structures
Topic: Does the shape that I draw the Lewis structure matter?
Replies: 14
Views: 92

Re: Does the shape that I draw the Lewis structure matter?

Since we have not talked about shapes yet in lecture I would say you probably do not have to worry about the shapes of Lewis structures. Once we learn it then you will have to take shape into account.
by AKhanna_3H
Sat Nov 02, 2019 3:43 pm
Forum: Ionic & Covalent Bonds
Topic: The net energy decrease when Na and Cl form NaCl
Replies: 2
Views: 30

Re: The net energy decrease when Na and Cl form NaCl

Na and Cl independently are less stable than when they are bonded because they have incomplete octets as ions. They bond together to achieve a lower energy state and are more stable.
by AKhanna_3H
Sat Nov 02, 2019 3:37 pm
Forum: Electronegativity
Topic: Oxygen and Electronegativity
Replies: 5
Views: 37

Re: Oxygen and Electronegativity

Electronegativity is a measure of the tendency of an atom to form a covalent bond. Fluorine is the most electronegative atom on the periodic table, meaning it has the highest tendency to form a covalent bond. Since Oxygen is close to Fluorine, it also has a relatively high electronegativity. Electro...
by AKhanna_3H
Sat Nov 02, 2019 3:28 pm
Forum: Dipole Moments
Topic: London Dispersion vs Van der waals
Replies: 2
Views: 33

Re: London Dispersion vs Van der waals

Dr. Lavelle said that these are the same thing, just different words for the same concept!
by AKhanna_3H
Thu Oct 31, 2019 12:00 am
Forum: Lewis Structures
Topic: Textbook question 2B.9
Replies: 1
Views: 35

Re: Textbook question 2B.9

Ions are drawn separated from each other because in ionic bonds, electrons are not shared like in covalent bonds. Rather, electrons are donated or accepted. Therefore, there are no shared electron pairs, and no need to draw single, double, triple bonds between two atoms.
by AKhanna_3H
Mon Oct 28, 2019 10:37 am
Forum: Administrative Questions and Class Announcements
Topic: Review Sessions
Replies: 2
Views: 56

Review Sessions

Are the review sessions for the midterm still happening tonight even though classes are cancelled?
by AKhanna_3H
Sat Oct 26, 2019 5:19 pm
Forum: Lewis Structures
Topic: Lewis Structure
Replies: 5
Views: 59

Re: Lewis Structure

The least electronegative atom goes in the center. Electronegativity increases as you go across the periodic table and decreases as you go down the periodic table.
by AKhanna_3H
Sat Oct 26, 2019 5:14 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge
Replies: 7
Views: 78

Re: Formal Charge

Dr. Lavelle said in lecture that the formal charge of an atom indicates a gain or loss of electrons when forming a covalent bond. Calculating formal charges is helpful in drawing the best possible Lewis structures and making sure that the overall charge of the molecule is represented in the Lewis st...
by AKhanna_3H
Sat Oct 26, 2019 4:25 pm
Forum: Lewis Structures
Topic: Sulfate Lewis Structure (From class)
Replies: 1
Views: 26

Re: Sulfate Lewis Structure (From class)

He started by finding how many valence electrons Sulfur and Oxygen had. Both have 6, and since there are 4 Oxygens present, there are a total of 32 electrons, so your Lewis structure should include 32 electrons. First he drew the diagram with Sulfur in the center and 4 Oxygens each with a single bon...
by AKhanna_3H
Sat Oct 26, 2019 4:04 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Assigning Orbitals to Elements
Replies: 4
Views: 49

Re: Assigning Orbitals to Elements

My TA said that you do not need to know how to do this. I believe he said there is no way to figure it out just from reading a problem, but he definitely said we would not have to do this on a midterm/test. Hope that helps!
by AKhanna_3H
Sat Oct 26, 2019 4:03 pm
Forum: Photoelectric Effect
Topic: kinetic energy
Replies: 6
Views: 77

Re: kinetic energy

The equation for this is on the formula sheet so you don't have to memorize it but you will most likely have to apply it to problems.
by AKhanna_3H
Wed Oct 16, 2019 2:52 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Bohr's Equation
Replies: 5
Views: 71

Re: Bohr's Equation

You might have to double check, but I believe the tests/midterms/finals are similar to the homework problems which involve calculations, so it is unlikely that you would have to derive an equation on a test. Hope this helps!
by AKhanna_3H
Wed Oct 16, 2019 2:49 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal plane for s-orbitals?
Replies: 3
Views: 41

Re: Nodal plane for s-orbitals?

A nodal plane by definition is a plane where the probability of finding an electron is 0. This means there are no planes for the s-orbital where the probability of finding an electron is 0.
by AKhanna_3H
Wed Oct 16, 2019 2:42 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Electron spin
Replies: 8
Views: 109

Re: Electron spin

I think that as long as you understand that +1/2 indicates a positive spin and -1/2 indicates a negative spin for the fourth quantum number, you should be good!
by AKhanna_3H
Tue Oct 15, 2019 4:42 pm
Forum: *Black Body Radiation
Topic: What is Black Body?
Replies: 6
Views: 146

Re: What is Black Body?

I also believe Dr. Lavelle said that it absorbs all radiation.
by AKhanna_3H
Tue Oct 15, 2019 4:16 pm
Forum: Photoelectric Effect
Topic: Speed of Light
Replies: 29
Views: 251

Re: Speed of Light

Yes it is a constant.
by AKhanna_3H
Sat Oct 12, 2019 8:25 pm
Forum: DeBroglie Equation
Topic: Knowing Which Equation to Use
Replies: 4
Views: 63

Re: Knowing Which Equation to Use

I usually start by figuring out what variables I know and then finding an equation that has the unknown variable in it, filling in all the known variables that apply to that equation.
by AKhanna_3H
Sat Oct 12, 2019 8:09 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Decreasing gap between energy level
Replies: 6
Views: 105

Re: Decreasing gap between energy level

As an electron gets farther away from the nucleus, the "pull" of the nucleus decreases in strength. Therefore the easier it is for an electron to jump to a higher energy level the farther away from the nucleus it is.
by AKhanna_3H
Sat Oct 12, 2019 8:02 pm
Forum: SI Units, Unit Conversions
Topic: Weekly Posts
Replies: 7
Views: 85

Re: Weekly Posts

You have to post 5 times by Sunday at 11:59 p.m.
by AKhanna_3H
Thu Oct 10, 2019 4:03 pm
Forum: SI Units, Unit Conversions
Topic: Course Reader
Replies: 6
Views: 131

Re: Course Reader

There is no course reader, the only required material is the textbook which also comes with a solution manual.
by AKhanna_3H
Wed Oct 09, 2019 3:11 pm
Forum: Limiting Reactant Calculations
Topic: Problem M.5
Replies: 2
Views: 74

Problem M.5

Could someone please explain how to approach problem M.5? Thanks!
by AKhanna_3H
Thu Oct 03, 2019 7:31 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Rounding
Replies: 12
Views: 245

Re: Rounding

In general, you would use the full number and then round to the correct number of significant figures as the last step of your calculations to get your final answer. For the most accuracy, avoid rounding any numbers in your calculations until the final answer.

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