Search found 82 matches

by Diana Chavez-Carrillo 2L
Sat Jan 25, 2020 6:02 pm
Forum: Ideal Gases
Topic: aqueous elements in eq calculation
Replies: 8
Views: 25

Re: aqueous elements in eq calculation

Solids and liquids like water are not included in the equilibrium calculation. Only gas or aqueous in the reaction are counted for. This is the same rule that applies when using the ICE tables and even with Le Chatelier's Principle because changes in the concentration of a liquid or a solid DO NOT a...
by Diana Chavez-Carrillo 2L
Sat Jan 25, 2020 5:52 pm
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: Ka*Kb=Kw
Replies: 5
Views: 24

Re: Ka*Kb=Kw

Kw= 10^-14 and Kw= 1.0 * 10 ^-14 are the same but I believe in the book they used 1.0 * 10 ^-14 because it helps keeping up with the sig figs. But remember that Kw=10 ^-14 ONLY at 25 degrees Celsius.
by Diana Chavez-Carrillo 2L
Sat Jan 25, 2020 5:45 pm
Forum: Phase Changes & Related Calculations
Topic: revere reactions
Replies: 7
Views: 27

Re: revere reactions

Would this be the same for going up a phase? Would it be endothermic in this case since now there is more heat required to break down the phase like a solid to liquid?
by Diana Chavez-Carrillo 2L
Sat Jan 25, 2020 5:26 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Partial Pressure vs. Concentration
Replies: 5
Views: 16

Re: Partial Pressure vs. Concentration

Usually in the problem will you be given molarity or moles and this will hint that you need to use concentration (Kc) but if the problem gives you atm or barr then you will use the partial pressure (Kp). However, the question should be clear about which one you should be using from the given informa...
by Diana Chavez-Carrillo 2L
Sat Jan 25, 2020 5:15 pm
Forum: Phase Changes & Related Calculations
Topic: Endothermic and Exothermic
Replies: 13
Views: 31

Re: Endothermic and Exothermic

In an endothermic reaction, heat is being absorbed so you can think of it as a reactant. In an exothermic reaction, heat is being released so you can think of it as a product. You can usually tell whether a reaction is endothermic or exothermic by looking at the given enthalpy. If the enthalpy is a ...
by Diana Chavez-Carrillo 2L
Fri Jan 17, 2020 11:24 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Buffer
Replies: 1
Views: 20

Buffer

In today's lecture Lavelle mentioned something about a Buffer, can someone explain this concept for me and how it relates to the pH of a weak acid/base and salt?
by Diana Chavez-Carrillo 2L
Fri Jan 17, 2020 11:19 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Difference between K and Q?
Replies: 11
Views: 28

Difference between K and Q?

The reaction quotient (Q) formula looks very similar to the formula used for the equilibrium constant, K so what is their difference? Is it just that K has to be at equilibrium or is there other differences between them?
by Diana Chavez-Carrillo 2L
Fri Jan 17, 2020 10:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Tips for Test
Replies: 16
Views: 53

Re: Tips for Test

I like to read the textbook chapters because they definitely do break down the topics and also I like to use Khan Academy to study for the tests. You can search up chemical equilibrium or acids and bases on khan academy and the lesson plans for them will pop up. I like using this resource because th...
by Diana Chavez-Carrillo 2L
Fri Jan 17, 2020 9:40 pm
Forum: Ideal Gases
Topic: final exam pickup
Replies: 8
Views: 59

Re: final exam pickup

I went today to the room in Young Hall and they said finals will for sure be available next week (week 3). I am also wondering whether the rationale for the final exam questions will be provided to us either online or with our physical exam? Also, in case there are some errors with the grading of ou...
by Diana Chavez-Carrillo 2L
Fri Jan 17, 2020 8:42 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Kc & Kp
Replies: 12
Views: 34

Re: Kc & Kp

Is it possible for there to be an equation with both gaseous particles and aqueous solutions? How would we go about solving this? Would we use a combination of Kc and Kp?
by Diana Chavez-Carrillo 2L
Fri Jan 17, 2020 12:40 pm
Forum: Ideal Gases
Topic: final exam pickup
Replies: 8
Views: 59

Re: final exam pickup

I was wondering the same thing and I checked my email because I remember Lavelle mentioned final exam pickups somewhere. He sent an email about the class average grades and at the bottom, he said: "Final exams will be available 3rd week Winter quarter from 3034 Young Hall." So I am going t...
by Diana Chavez-Carrillo 2L
Fri Jan 17, 2020 12:21 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Homework question 5H.1 PART B
Replies: 2
Views: 12

Homework question 5H.1 PART B

For the homework problem 5H.1 part B it contains fractions as the stoichiometric coefficient: 1/2 N2 + 3/2 H2 -> NH3. In the solution manual they placed 41 (this number is K=41 which came from part A) to the power of 1/2 and got 6.4 as the value of K for this equation but I am confused about where y...
by Diana Chavez-Carrillo 2L
Fri Jan 10, 2020 5:52 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Difference between lies, sits, and shifts
Replies: 4
Views: 17

Re: Difference between lies, sits, and shifts

They essentially mean the same thing, and another one you might see is that it "favors" one side. Okay, I see thank you! However, for the "favors" part I remember seeing in his module (the first module I believe) where K>1 means that there is a "slight" favoring of pro...
by Diana Chavez-Carrillo 2L
Fri Jan 10, 2020 5:33 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Difference between lies, sits, and shifts
Replies: 4
Views: 17

Difference between lies, sits, and shifts

I know Professor Lavelle kept emphasizing how elements can't literally sit or lie anywhere but I was confused on their differences because I see that they can be used interchangeably so do they all mean the same thing? For example, if K>1 then would we say it shifted, lies, or sits to the right?
by Diana Chavez-Carrillo 2L
Thu Jan 09, 2020 9:40 pm
Forum: Student Social/Study Group
Topic: Homework for Week 1
Replies: 6
Views: 34

Re: Homework for Week 1

Professor Lavelle announced in class that homework 1 will be turned in after the lecture on Friday (tomorrow 01/10). However, this is only for week 1 so for week 2 and the following weeks the homework (5 problems) will be turned in to your TAs when you have your discussion sections.
by Diana Chavez-Carrillo 2L
Thu Jan 09, 2020 9:18 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Units for K
Replies: 10
Views: 44

Re: Units for K

To go off of the previous responses, although units are omitted when we write K we write a C or P next to it which indicates the units we are using without necessarily writing them. The purpose of this is to make sure that it is clear whether we are calculating concentration or pressure. For Kc, it ...
by Diana Chavez-Carrillo 2L
Thu Jan 09, 2020 8:54 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Clarification on equilibrium
Replies: 3
Views: 13

Re: Clarification on equilibrium

In the first module Lavelle mentioned how K>1 means that there is slight favoring of products and K<1 measn there is slight favoring of reactants. Are K< or > 1 and K< or > 10^3 or 10^-3 not the same and why? I remember in lecture Lavelle mentioning how for K< or > 10^3 or 10^-3 you either favor the...
by Diana Chavez-Carrillo 2L
Thu Jan 09, 2020 8:28 pm
Forum: Administrative Questions and Class Announcements
Topic: Solutions Manual
Replies: 4
Views: 28

Re: Solutions Manual

Did you buy the bundle or the book separately because I had bought the bundle and it came with a solution Manual book? The solution manual is an orange book but if you do not have it then I believe you can also find the answers to the homework questions on the back of the textbook.
by Diana Chavez-Carrillo 2L
Thu Jan 09, 2020 8:23 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 5G.7
Replies: 5
Views: 32

Re: 5G.7

this is unrelated but can someone help me please? I can't figure out how to post something without replying to someone... The way that I have done it is with the following steps: 1. On the top left-hand corner, you should see the word/link "Board Index" (click it) 2. Scroll down to the Ch...
by Diana Chavez-Carrillo 2L
Thu Jan 09, 2020 6:45 pm
Forum: Administrative Questions and Class Announcements
Topic: Sapling Learning
Replies: 9
Views: 47

Re: Sapling Learning

I remember that some students from 14A mentioned how there were practice questions on Sapling Learning and Lavelle emphasized that students should do them. Anyone who has used the Sapling Learning for 14A was the questions similar to the exam questions and would they be helpful for 14B?
by Diana Chavez-Carrillo 2L
Mon Jan 06, 2020 9:38 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: HW Problem 5G.7
Replies: 4
Views: 41

Re: HW Problem 5G.7

I was confused as well as to why the solution manual did not write Kp and just wrote K. However, on the solution manual the ratio was written with "P" in front of each reactant or product which indicates that the ratio is the equilibrium of their partial pressures. Based on Lavelle's modul...
by Diana Chavez-Carrillo 2L
Sun Dec 08, 2019 9:41 am
Forum: Naming
Topic: Naming
Replies: 7
Views: 44

Re: Naming

Reina Robles 1H wrote:You use those when the ligand already contains a prefix (for example, (en)), is a polydentate, or it starts with a vowel.

I hope this helps!


Just to clarify, we only use prefixes for whats inside the brackets and not on the cation or anion outside the brackets correct?
by Diana Chavez-Carrillo 2L
Sun Dec 08, 2019 9:27 am
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Memorizing Ligands
Replies: 3
Views: 47

Re: Memorizing Ligands

For sure know ethylenediamine (en), oxalato (ox), and ethylenediaminetetraacetato (edta) because they are chelating ligands!
by Diana Chavez-Carrillo 2L
Sun Dec 08, 2019 9:06 am
Forum: General Science Questions
Topic: Final exam
Replies: 3
Views: 94

Re: Final exam

Will the test focus more on the first or second half of the class? The exam will be cumulative so expect to apply concepts together because many of the concepts we learned in the first half of the class apply to the second half such as molarity and calculating pH. So I am pretty sure there will be ...
by Diana Chavez-Carrillo 2L
Sun Dec 08, 2019 8:58 am
Forum: Hybridization
Topic: Writing the hydrization
Replies: 10
Views: 83

Re: Writing the hydrization

Hello, I have a question about the difference between 2sp3 and sp3. How do you know if the "2" in front of the sp3 is supposed to be there? What's the difference between the two? It’s the quantum number of the central atom when you’re talking about the hybridization of a molecule. Describ...
by Diana Chavez-Carrillo 2L
Sun Dec 08, 2019 8:52 am
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4085

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

#16 why is the trigonal planar shape considered nonpolar, how did we determine this ? AX3 means that the central atom (A) will have 3 atoms attached to it (X3). This results in a trigonal planar shape. To determine its polarity usually if the attached atoms are all the same type of atom and the cen...
by Diana Chavez-Carrillo 2L
Sat Dec 07, 2019 6:03 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4085

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

In the marshmallow packet, for question 28, for example, would it be acceptable to write (en) instead of the full name: ethylenediammine or do we need to write out the full name to get credit?
by Diana Chavez-Carrillo 2L
Sat Dec 07, 2019 5:52 pm
Forum: Administrative Questions and Class Announcements
Topic: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]
Replies: 111
Views: 4085

Re: MARSHMALLOW- FINAL REVIEW SESSION [ENDORSED]

for question 40c, how do you know whether o2 or o3 has the stronger bond and why? o2 has double bonds that are shorter and therefore stronger than the o3 bonds, which is between a single and double bond due to resonance. So then is the stronger bond O2 because in a way O3 has like an average bond s...
by Diana Chavez-Carrillo 2L
Fri Nov 29, 2019 5:53 pm
Forum: Hybridization
Topic: Writing the hydrization
Replies: 10
Views: 83

Writing the hydrization

When asked what the hybridization is when do we have to write, for example, 2sp3 or just sp3?
by Diana Chavez-Carrillo 2L
Fri Nov 29, 2019 5:44 pm
Forum: Naming
Topic: Naming coordination compound
Replies: 5
Views: 48

Re: Naming coordination compound

When do you use the suffix ide or ate? When you are dealing with a molecule that is NOT a ligand and is an ANION and outside of the brackets then you add the suffix -ide because it does not follow the ligand rules. For an anionic (negative charge) metal (inside the bracket), you add the suffix -ate.
by Diana Chavez-Carrillo 2L
Fri Nov 29, 2019 5:28 pm
Forum: Naming
Topic: Amine vs Ammine?
Replies: 3
Views: 52

Re: Amine vs Ammine?

Are you talking about ammine for the neutral lignad: NH3 and about their spelling? If so, I was told in one of my plf's that the spelling matters in regards to points so when naming coordination compounds make sure you write ammine with double m's!
by Diana Chavez-Carrillo 2L
Fri Nov 29, 2019 5:22 pm
Forum: Administrative Questions and Class Announcements
Topic: Studying for the Final [ENDORSED]
Replies: 11
Views: 180

Re: Studying for the Final [ENDORSED]

I would say to definitely do the homework problems and review them because they give you a good idea of how the questions for the test can be structured. Also, I would say it would be a good idea to read over your notes and attend UA's sessions since they sometimes provide and go over practice probl...
by Diana Chavez-Carrillo 2L
Wed Nov 27, 2019 2:03 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: How to take the log to get the pH?
Replies: 8
Views: 50

Re: How to take the log to get the pH?

AngieGarcia_4F wrote:If you were given a Hydrogen concentration of [H+]=0.1M, for example, and asked to find the pH, you would plug the concentration into the formula pH=-log[H+]; pH=-log[0.1M], and just plug it into your calculator.


So would our answer just be 1? Also, would this be interpreted as our pH being 1?
by Diana Chavez-Carrillo 2L
Wed Nov 20, 2019 11:30 am
Forum: Sigma & Pi Bonds
Topic: Resonance Structures in 2F.3
Replies: 4
Views: 25

Re: Resonance Structures in 2F.3

Based on the type of questions that were given to us from some of the UAs the questions are phrased by saying "refer to the LOWEST ENERGY structure of..." or "refer to the MOST STABLE Lewis structure of..." So I am sure that the majority of the time we will be asked to draw and u...
by Diana Chavez-Carrillo 2L
Tue Nov 19, 2019 10:33 pm
Forum: General Science Questions
Topic: Test 2
Replies: 7
Views: 94

Re: Test 2

I believe we will have to memorize all the shapes because in Test 2 we will be tested on drawing the Lewis structures, determining the shapes, bond angles, etc. as we have done with the practice problems in lecture with Lavelle.
by Diana Chavez-Carrillo 2L
Tue Nov 19, 2019 10:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: See-Saw Shape
Replies: 3
Views: 28

Re: See-Saw Shape

Yes if asked for one bond angle then you can either say it is slightly less than 90 degrees or slightly less than 120 degrees. The reason for this is because the one lone pair causes electron repulsion than push the atoms closer together because the atoms want to minimize the electron repulsion expe...
by Diana Chavez-Carrillo 2L
Tue Nov 19, 2019 9:36 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Regions of electron density
Replies: 5
Views: 46

Re: Regions of electron density

VSEPR Table.pdf Really? Do you know where I can find his post?? [/quote] Wow! Thank you so much this helps a lot! Quick question about the chart so in domain 6 is the angle for AX5E less than 90 degrees? And is the reason why the bond angles in AX4E2 still 90 degrees because of the two lone pairs i...
by Diana Chavez-Carrillo 2L
Tue Nov 19, 2019 9:04 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Regions of electron density
Replies: 5
Views: 46

Re: Regions of electron density

alicechien_1I wrote:I believe we only need to know up to octahedral. Dr. Lavelle made a post with the list of molecular geometries to know for the test. Hope this helps!


Really? Do you know where I can find his post??
by Diana Chavez-Carrillo 2L
Tue Nov 19, 2019 8:51 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Regions of electron density
Replies: 5
Views: 46

Regions of electron density

Up to what steric number (region of electron density) should we know/memorize for VSEPR? I know that it can go up to steric number 7 for example which the shape would be called pentagonal bipyramidal.
by Diana Chavez-Carrillo 2L
Tue Nov 19, 2019 7:58 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: induced dipole-induced dipole
Replies: 4
Views: 33

Re: induced dipole-induced dipole

Induced dipole - induced dipole is the same as London's dispersion right? I keep hearing people refer to this intermolecular force as either induced dipole - induced dipole or London's dispersion so I just want to make sure if they mean the same thing?
by Diana Chavez-Carrillo 2L
Wed Nov 13, 2019 7:11 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Linear VSEPR model
Replies: 21
Views: 122

Re: Linear VSEPR model

So the number of lone pairs can also determine the molecular shape of a molecule? Yes, lone pairs can influence the molecular shape of a molecule but as mentioned by the previous responses we have not gone over it yet. However, to have an idea of some examples I provided an image below that shows y...
by Diana Chavez-Carrillo 2L
Wed Nov 13, 2019 2:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Topics on Outlines for Test 2
Replies: 3
Views: 29

Re: Topics on Outlines for Test 2

I believe Test 2 should be what was not covered on the midterm and the next chapter with Molecular Shape and Structure. This includes 3F which was what we did not cover from the midterm and Outline 4: Molecular Shape and Structure.
by Diana Chavez-Carrillo 2L
Wed Nov 13, 2019 2:33 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Test 2
Replies: 15
Views: 151

Re: Test 2

I feel like definitely VESPR models like the practice we did today in class drawing the lewis structure, calculating the angles and determining the shape would be on there. So I would say study 3F (since we did not cover it in the midterm) and 2E-F.
by Diana Chavez-Carrillo 2L
Wed Nov 13, 2019 2:26 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Linear VSEPR model
Replies: 21
Views: 122

Re: Linear VSEPR model

So the number of lone pairs can also determine the molecular shape of a molecule? Yes, lone pairs can influence the molecular shape of a molecule but as mentioned by the previous responses we have not gone over it yet. However, to have an idea of some examples I provided an image below that shows y...
by Diana Chavez-Carrillo 2L
Tue Nov 12, 2019 9:08 pm
Forum: Bond Lengths & Energies
Topic: Homework for week 7
Replies: 5
Views: 41

Re: Homework for week 7

Yes, my TA said we can do HW problems from chemical bonds and/or molecular shape and structure since we did not cover all of the chemical bonds and Lavelle finished covering it after the midterm. But I would suggest you try to do more HW problems on the section with molecular shape and structure sin...
by Diana Chavez-Carrillo 2L
Mon Nov 04, 2019 2:53 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarity vs Polarizability
Replies: 3
Views: 42

Re: Polarity vs Polarizability

Polarizability is the ability of an atom to form temporary dipoles. In other words, it is the ability to be polarized by another. Polarizing power is the ability to polarize another. Typically a bigger atomic radius means higher polarizability because a bigger electron cloud is more easily distorted...
by Diana Chavez-Carrillo 2L
Mon Nov 04, 2019 2:13 pm
Forum: Resonance Structures
Topic: Octet
Replies: 13
Views: 84

Re: Octet

So far what I have gathered from TAs and Lavelle's lectures, the exceptions include the following: Incomplete octets (meaning it can have less than 8 electrons) are the first 4 elements on the periodic table: H, He, Li, Be, AND B, Al. Expanded octets (meaning it can have more than 8 electrons) are e...
by Diana Chavez-Carrillo 2L
Mon Nov 04, 2019 2:00 pm
Forum: Trends in The Periodic Table
Topic: ionization energy vs electronegativity
Replies: 4
Views: 23

Re: ionization energy vs electronegativity

Just keep in mind that the ionzation energy trend is not exactly the same as the electronegativity trend because for ionization energy there is an exception when it comes to Nitrogen and Oxygen. For the most part, ionization energy does increase going up and across to the right of the periodic table...
by Diana Chavez-Carrillo 2L
Mon Nov 04, 2019 1:52 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy from the Review
Replies: 4
Views: 27

Re: Ionization Energy from the Review

So then when it comes to ionization energy is the only exemptions nitrogen and oxygen? Are the rest of the elements still increasing in ionization energy going up and across to the right of the periodic table which is the same trend as electronegativity on the periodic table?
by Diana Chavez-Carrillo 2L
Mon Nov 04, 2019 1:32 pm
Forum: General Science Questions
Topic: Midterm
Replies: 12
Views: 169

Re: Midterm

Does anyone know if we can use whiteout during the midterm exam? I know we are supposed to write in pen so I was wondering if we could use whiteout since we do have a limited amount of space to do calculations.
by Diana Chavez-Carrillo 2L
Wed Oct 30, 2019 11:29 pm
Forum: Electronegativity
Topic: Electronegativity trends
Replies: 5
Views: 29

Re: Electronegativity trends

Yes, electronegativity counts as a trend on the periodic table. It is important for things like determining if elements have an ionic bond or a covalent bond. Electronegativity, electron affinity, and ionization energy have the same trend (increase up the table and to the right across the periodic t...
by Diana Chavez-Carrillo 2L
Wed Oct 30, 2019 10:43 pm
Forum: Ionic & Covalent Bonds
Topic: Midterm
Replies: 28
Views: 183

Re: Midterm

Since we need to know the electronegativity differences to determine if there are ionic bonds or covalent bonds, will we be given on the midterm an electronegativity chart that shows each element's electronegativity or do we need to memorize them?
by Diana Chavez-Carrillo 2L
Wed Oct 30, 2019 10:36 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Test 1 [ENDORSED]
Replies: 107
Views: 2782

Re: Test 1 [ENDORSED]

Will we be given some sort of answer key or rationale for the correct answers in Test 1 in order to review our mistakes and thus study for the midterm that will include questions similar to Test 1?
by Diana Chavez-Carrillo 2L
Wed Oct 30, 2019 10:00 pm
Forum: Ionic & Covalent Bonds
Topic: ionic vs covalent bonds
Replies: 6
Views: 38

Re: ionic vs covalent bonds

In today's lecture (10/30/19) Lavelle mentioned how Cl has a (-) charge while K is (+) charge. I know its probably really simple but could someone please clarify/remind me how do we determine if an element is +1 or -1. For example, how is Cl becoming into Cl-1 and K becoming K+.
by Diana Chavez-Carrillo 2L
Wed Oct 30, 2019 9:53 pm
Forum: Ionic & Covalent Bonds
Topic: Format of midterm?
Replies: 12
Views: 68

Re: Format of midterm?

Would we still be given partial credit for questions on the midterm like Test 1 or no?
by Diana Chavez-Carrillo 2L
Thu Oct 24, 2019 1:16 pm
Forum: Trends in The Periodic Table
Topic: Summary of Periodic Trends
Replies: 7
Views: 75

Re: Summary of Periodic Trends

Is electron affinity only important/ only affects Group 17 (according to Lavelle) and noble gases? Or why is it important to know the electron affinity?
by Diana Chavez-Carrillo 2L
Thu Oct 24, 2019 12:23 pm
Forum: Trends in The Periodic Table
Topic: Trends
Replies: 5
Views: 46

Re: Trends

I think some of the main trends you should keep in mind are: Electron affinity: Lavelle mentioned that this is less periodic but generally there is HIGH electron affinity for elements in the TOP RIGHT of the periodic table (Group 17). Atomic radius : increases DOWN the periodic table increases FROM ...
by Diana Chavez-Carrillo 2L
Thu Oct 24, 2019 11:54 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: coulomb potential energy
Replies: 4
Views: 35

Re: coulomb potential energy

What does the infinity-like symbol next to the equation (q1)(q2)/r mean?
Also, would we need this equation to do calculations or is it just the concept about like attraction and potential energy that we need to understand?
by Diana Chavez-Carrillo 2L
Thu Oct 24, 2019 11:17 am
Forum: Administrative Questions and Class Announcements
Topic: KAREN SUN 5-7PM WORKSHOP - DOWNLAOD WORKSHEETS HERE
Replies: 53
Views: 2432

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

Does anyone know if any other UAs post their worksheets on Chemistry Community?? These worksheets are so helpful especially for me whose high school chemistry background is essentially nonexistent. Thank you so much Karen for posting these! Yeah, I found another UA who posts helpful worksheets too ...
by Diana Chavez-Carrillo 2L
Wed Oct 23, 2019 2:54 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configurations for electrons in the D subshell
Replies: 5
Views: 49

Re: Electron Configurations for electrons in the D subshell

Could someone explain to me why is it that when you start to include the d into our electron configuration the order is that d goes first then s. In highschool I was taught to just follow the order where it is s then p for the first 3 rows but then for the 4th row it would be s, d, p but I see that ...
by Diana Chavez-Carrillo 2L
Thu Oct 17, 2019 8:05 pm
Forum: Quantum Numbers and The H-Atom
Topic: quantum number topic
Replies: 4
Views: 38

Re: quantum number topic

n is the principal quantum number that shows the number of shells and indicates the size and energy. l is the angular momentum quantum number that indicates the shape. ml shows the orbitals. ml is not the same number as l because l is the subshells that consist of 0 (s orbital),1 (p orbital),2 (d or...
by Diana Chavez-Carrillo 2L
Thu Oct 17, 2019 1:18 pm
Forum: Quantum Numbers and The H-Atom
Topic: 1D.25
Replies: 2
Views: 24

Re: 1D.25

A subshell notation is basically whether it will be s, p, d, etc. So if n=2 and l=1 then the subshell will be 2p because l=0 is "s," l=1 is "p", l=2 would have been "d", etc.
by Diana Chavez-Carrillo 2L
Thu Oct 17, 2019 12:41 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quantum Numbers
Replies: 7
Views: 78

Re: Quantum Numbers

I am still confused about how to calculate the magnetic quantum number (ml) based on the principal quantum number (n) and angular momentum number( l ). Could someone please explain to me the process of finding it? Like I know that (l) is dependent on (n) but the (ml) still confuses me. m l is the m...
by Diana Chavez-Carrillo 2L
Wed Oct 16, 2019 2:35 pm
Forum: Properties of Light
Topic: Midterm- Electromagnetic spectrum
Replies: 3
Views: 33

Re: Midterm- Electromagnetic spectrum

I think it would be important if you at least get a general idea of where each electromagnetic radiation is like gamma rays being in the left side (before visible light) with the highest Energy and radios being in the right side (after the visible light spectrum which is usually in the middle) where...
by Diana Chavez-Carrillo 2L
Wed Oct 16, 2019 2:14 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Quantum Numbers
Replies: 7
Views: 78

Re: Quantum Numbers

I am still confused about how to calculate the magnetic quantum number (ml) based on the principal quantum number (n) and angular momentum number( l ). Could someone please explain to me the process of finding it? Like I know that (l) is dependent on (n) but the (ml) still confuses me. For example, ...
by Diana Chavez-Carrillo 2L
Wed Oct 16, 2019 1:44 pm
Forum: Properties of Light
Topic: Constant for Speed of Light
Replies: 14
Views: 86

Constant for Speed of Light

I am wondering what constant would Lavelle prefer/require us to use throughout our homework problems and next exam when it comes to speed of light because the Solution Manual used 2.998*10^8 m*s^-1 but in my PLF we used 3.0*10^8 m*s^-1. I am aware that each one can you give you a different answer so...
by Diana Chavez-Carrillo 2L
Wed Oct 09, 2019 2:35 pm
Forum: Empirical & Molecular Formulas
Topic: Molecular formula
Replies: 6
Views: 150

Re: Molecular formula

Everyone above is correct but I personally like to see actual examples to better understand a concept so I provided you with a step-by-step example I solved from a cool website that provides practice problems like this https://chem.libretexts.org : Determine the empirical and molecular formula for c...
by Diana Chavez-Carrillo 2L
Wed Oct 09, 2019 2:22 pm
Forum: Significant Figures
Topic: Are we allowed to round when showing work?
Replies: 7
Views: 52

Re: Are we allowed to round when showing work?

I would personally say to write out your calculations exactly as you input them on your calculator ( unrounded) because if you do by any chance make a mistake with your sig figs in your final answer then your TA will look at your work (for partial credit) and by providing the unrounded values they w...
by Diana Chavez-Carrillo 2L
Wed Oct 09, 2019 1:58 pm
Forum: SI Units, Unit Conversions
Topic: Homework Grading Clarification [ENDORSED]
Replies: 8
Views: 343

Re: Homework Grading Clarification [ENDORSED]

So say we complete every part of the question correctly, but right at the end we mess up on our sig figs, we'll still get no credit for any of our previous work? In my discussion, one of the students asked this to our TA and he said that you will be able to get partial credit if you show your work ...
by Diana Chavez-Carrillo 2L
Wed Oct 09, 2019 1:38 pm
Forum: Significant Figures
Topic: Question About Significant Figures and Rounding
Replies: 22
Views: 307

Re: Question About Significant Figures and Rounding

When we add molar masses of elements to get the total matter weight of compounds, should I use the entire number that the periodic table gives? or should I round certain numbers? I noticed that the periodic table Lavelle has shown us compared to one I had back home has different amount of numbers a...
by Diana Chavez-Carrillo 2L
Wed Oct 09, 2019 1:10 pm
Forum: Administrative Questions and Class Announcements
Topic: Week 2 Homework Problems [ENDORSED]
Replies: 67
Views: 1631

Re: Week 2 Homework Problems [ENDORSED]

Are the TA's grading our homework based on completion or correctness?
by Diana Chavez-Carrillo 2L
Wed Oct 02, 2019 7:29 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: How to access e textbook
Replies: 4
Views: 60

Re: How to access e textbook

The sapling came in my bundle but to be completely honest I am not sure what is it used for like is it to just access an online version of the textbook or is there other important information we can only access through the sapling code/booklet that came with the bundle?
by Diana Chavez-Carrillo 2L
Wed Oct 02, 2019 7:16 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Solubility Rules Memorization ?
Replies: 3
Views: 47

Re: Solubility Rules Memorization ?

To build off of that question, if the question shows the solubility like (l) or (s) or (aq) would it matter if throughout our problem solving and the final answer it does not have the solubility or do we have to include it throughout and the final answer?
by Diana Chavez-Carrillo 2L
Wed Oct 02, 2019 7:06 pm
Forum: Empirical & Molecular Formulas
Topic: Homework question M.17
Replies: 2
Views: 42

Homework question M.17

In my discussion, we were working on problem M.17 but did not get to finish it and I got stuck near the end of solving the problem so I went to the Solution Manual and for "finding the molar mass of XA" it set it up as (231-1.0) + (125-17) to equal 338 g/mol. However, I do not understand w...
by Diana Chavez-Carrillo 2L
Tue Oct 01, 2019 11:43 pm
Forum: Significant Figures
Topic: Question About Significant Figures and Rounding
Replies: 22
Views: 307

Re: Question About Significant Figures and Rounding

As a visual learner, I found the following images attached below that have helped me better understand the rules with sig figs. Hopefully, it can help some of you too. In sum, nonzero digits always count as a sig fig. For zero digits, if its inbetween nonzero digits it counts and if the zeros are af...
by Diana Chavez-Carrillo 2L
Tue Oct 01, 2019 10:59 pm
Forum: Empirical & Molecular Formulas
Topic: Mass % Composition
Replies: 7
Views: 87

Re: Mass % Composition

I am still a bit confused about when to divide the mass percentage by 100g and when to just take the percentage and make it into grams. For example, in the homework problem E.11, we took the percentages like 7.42% from one of the isotopes and divided by 100 to get 0.0742. However, when looking at th...
by Diana Chavez-Carrillo 2L
Thu Oct 11, 2018 5:52 pm
Forum: General Science Questions
Topic: Periodic Table
Replies: 16
Views: 569

Re: Periodic Table

It is best and safer to just keep the number exactly as seen on the periodic table so that you do not round too much. Usually you do the rounding until the very end of your calculations.
by Diana Chavez-Carrillo 2L
Thu Oct 11, 2018 4:57 pm
Forum: Significant Figures
Topic: Rounding Using Significant Figures
Replies: 10
Views: 559

Re: Rounding Using Significant Figures

What is the rule with the zeros when counting sig figs because I know that there are times you do not count the zero as a sig fig but sometimes you do. When do you know to count the zero as a sig fig?
by Diana Chavez-Carrillo 2L
Thu Oct 11, 2018 4:52 pm
Forum: Administrative Questions and Class Announcements
Topic: Number of questions on test one [ENDORSED]
Replies: 39
Views: 17870

Re: Number of questions on test one [ENDORSED]

If we do not understand what a question on the test asks is it allowed to ask for clarity from our TA's?
by Diana Chavez-Carrillo 2L
Wed Oct 03, 2018 8:36 pm
Forum: SI Units, Unit Conversions
Topic: Homework Grading Clarification [ENDORSED]
Replies: 8
Views: 343

Re: Homework Grading Clarification [ENDORSED]

Is it possible to get partial credit for homework problems?
by Diana Chavez-Carrillo 2L
Wed Oct 03, 2018 8:31 pm
Forum: SI Units, Unit Conversions
Topic: Textbook Homework Assignment
Replies: 11
Views: 588

Re: Textbook Homework Assignment

Is it possible to get credit if you do all the problems rather than just 7 problems?
by Diana Chavez-Carrillo 2L
Wed Oct 03, 2018 7:45 pm
Forum: General Science Questions
Topic: Sig Figs
Replies: 9
Views: 931

Re: Sig Figs

How can you check if your sig. figs. are too precise or not rounded off enough?

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