Search found 46 matches
- Sat Dec 08, 2018 12:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
- Replies: 118
- Views: 20138
Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
How do we determine the hybridization on the lone pair? For example, if O is bonded to two atoms and has two lone pairs, wouldn't it just be sp3 or is there another specific notation for the lone pair I am missing?
- Sat Dec 08, 2018 12:10 pm
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
- Replies: 118
- Views: 20138
Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Can someone explain the bond angles in number 18?
- Fri Dec 07, 2018 3:00 pm
- Forum: Lewis Acids & Bases
- Topic: How to tell if an ion is acidic or basic?
- Replies: 2
- Views: 281
How to tell if an ion is acidic or basic?
Are positively charged ions always acidic because they can accept an electron pair? Are the negatively charged ions basic because they will give it up?
- Fri Dec 07, 2018 2:57 pm
- Forum: Lewis Acids & Bases
- Topic: How to tell if an ion is acidic or basic?
- Replies: 1
- Views: 216
How to tell if an ion is acidic or basic?
Are positively charged ions always acidic because they can accept an electron pair? Are the negatively charged ions basic because they will give it up?
- Fri Dec 07, 2018 2:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
- Replies: 118
- Views: 20138
Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Thank you so much!
- Wed Dec 05, 2018 1:42 pm
- Forum: Naming
- Topic: Anionic ligands
- Replies: 5
- Views: 567
Re: Anionic ligands
Did lavelle ever explicitly say that we had to memorize all the ligands on that worksheet?
- Tue Dec 04, 2018 8:06 pm
- Forum: Lewis Acids & Bases
- Topic: Acid but acidity is not due to its disassociation
- Replies: 1
- Views: 269
Acid but acidity is not due to its disassociation
When Boron accepts electron pairs in the form of OH- from water, its acidity is not due to its disassociation. Can someone please explain the concept behind this? Thank you!
- Wed Nov 28, 2018 6:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Week 8 Worksheet (3A3I3K)
- Replies: 5
- Views: 943
Re: Week 8 Worksheet (3A3I3K)
can anyone explain why N2 has a lower boiling point than C4H8? also, in general what is a good way to rank the bond length/boiling point?
- Mon Nov 26, 2018 3:54 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: test #3
- Replies: 14
- Views: 1442
Re: test #3
Also, are we responsible for memorizing the bond angles for each shape?
- Mon Nov 26, 2018 3:32 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: CN- v O2 stability
- Replies: 2
- Views: 388
Re: CN- v O2 stability
does that also mean it is a stronger bond?
- Mon Nov 26, 2018 3:30 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: CN- v O2 stability
- Replies: 2
- Views: 388
CN- v O2 stability
Why is CN- more stable than O2?
- Wed Nov 21, 2018 3:28 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Electron pair arrangement, actual structure
- Replies: 3
- Views: 327
Re: Electron pair arrangement, actual structure
Also, how would we be asked on a question to distinguish the two? If we are asked for the shape, is it assumed that we give both, or just the actual shape?
- Wed Nov 21, 2018 3:27 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Electron pair arrangement, actual structure
- Replies: 3
- Views: 327
Electron pair arrangement, actual structure
What is the difference between electron pair arrangement and actual structure? For example, a molecules arrangement can be trigonal bypyramidal, but its actual structure is seesaw.
- Wed Nov 21, 2018 1:14 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Difference between O2- and N3-
- Replies: 3
- Views: 3081
Difference between O2- and N3-
In the solutions manual of the textbook, it says that N3- is more polarizable than O2-. I know that polarizability increases as the atom gets bigger and has less charge. N3- is bigger than O2-, but it also has more charge. Does this mean that when the pattern is not consistent, it is more important ...
- Thu Nov 15, 2018 3:16 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: bond angles with lone electrons
- Replies: 2
- Views: 301
Re: bond angles with lone electrons
The lone pair on the central atom represents the ability of the lone pair to push the other bonded atoms closer together. The way the bond angles are determined are first based on what the normal bond angles would be without the addition of an extra electron pair. The extra electron pair is the reas...
- Wed Nov 14, 2018 10:12 am
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Difference between polarizability and polarizing power.
- Replies: 1
- Views: 282
Difference between polarizability and polarizing power.
Is there a difference between polarizability and polarizing power, and what determines if a molecule or ion has a greater polarizability or polarizing power?
- Mon Nov 12, 2018 5:41 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Net Number Of Moles
- Replies: 5
- Views: 2335
Re: Net Number Of Moles
You add up the total number of moles after a reaction and subtract the number of moles before the reaction.
- Mon Nov 12, 2018 5:40 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Test 3 dates?
- Replies: 11
- Views: 1214
Re: Test 3 dates?
Test 3 is the week after Thanksgiving so it shouldn't be a problem.
- Mon Nov 12, 2018 5:39 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Step Up Sessions
- Replies: 2
- Views: 350
Re: Step Up Sessions
There were no sessions today. Dr. Lavelle sent out an email.
- Sun Nov 04, 2018 10:43 am
- Forum: Octet Exceptions
- Topic: Resonance Structures
- Replies: 7
- Views: 788
Resonance Structures
When finding the different resonance structures, I am wondering which ones we actually include in the answer. For example, hydrogen phosphate has a structure that obeys the octet rule and another structure where it forms a double bond. The double bond can move between the three oxygens so that gives...
- Sun Nov 04, 2018 8:15 am
- Forum: Octet Exceptions
- Topic: Adding a Double bond or leaving a lone pair [ENDORSED]
- Replies: 3
- Views: 390
Re: Adding a Double bond or leaving a lone pair [ENDORSED]
Is there a maximum of double bonds an atom can make? For example, can an atom make 4 double bonds or does that exceed the number of atoms it can bond with.
- Sat Nov 03, 2018 2:15 pm
- Forum: Octet Exceptions
- Topic: Which atom gets extra lone pair
- Replies: 2
- Views: 243
Which atom gets extra lone pair
How do you know which atom gets the extra lone pair in a molecule, if they are both below n=3?
- Sat Nov 03, 2018 2:15 pm
- Forum: Octet Exceptions
- Topic: Adding a Double bond or leaving a lone pair [ENDORSED]
- Replies: 3
- Views: 390
Adding a Double bond or leaving a lone pair [ENDORSED]
How do we know when to add a double bond (Extra bond) for an expanded octet or when to keep it a lone pair?
- Mon Oct 22, 2018 9:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
- Replies: 135
- Views: 37533
Re: DOWNLOAD SESSION WORKSHEETS HERE - Sundays 4-6pm (Karen) [ENDORSED]
For question 7 on worksheet 2, why is it not possible to use the eqn in the book that says v= R(1/ni ^2 - 1/nf^2). I tried this just to see if I got the same answer and I didn't. Why doesn't this work as well, because we are using frequency to get n initial?
- Mon Oct 22, 2018 9:01 pm
- Forum: Properties of Electrons
- Topic: Predicting Nodal Planes
- Replies: 2
- Views: 409
Re: Predicting Nodal Planes
There is a pattern, and that is what the book means by predicting. The s block has 0 nodal planes. because it is symmetrical. The p block has 1 nodal plane. The d block has 2 nodal planes. So based on this information even if you didn't know how many the f block has, the pattern would allow you to a...
- Mon Oct 22, 2018 7:09 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Concept Question on Study Guide
- Replies: 1
- Views: 237
Concept Question on Study Guide
Can someone explain how to use the Bohr frequency condition to explain the origin of lines in the spectrum of an element? Thank you!
- Mon Oct 22, 2018 7:07 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Conceptual Question [ENDORSED]
- Replies: 1
- Views: 213
Conceptual Question [ENDORSED]
Can someone explain the concept behind the question of the study sheet... "With respect to electron transitions that give rise to a UV or visible spectrum: understand the difference between electronic transitions in atomic orbitals (atomic spectroscopy) and electronic transitions in molecular o...
- Sun Oct 21, 2018 3:20 pm
- Forum: Trends in The Periodic Table
- Topic: Test 2 Topics Covered Question
- Replies: 2
- Views: 274
Test 2 Topics Covered Question
On Friday's lecture (12-12:50), Dr. Lavelle mentioned that we are only responsible for what was covered until that day. The topic covered on that day was multi- electron systems which is the set of "E" problems in the seventh edition of the book. However, on the topic 2 outline, it says th...
- Sun Oct 21, 2018 1:52 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: What is a node?
- Replies: 2
- Views: 115
What is a node?
The textbook explains a node as a region in space where the wave function passes through 0. In my notes, I have information on nodal planes, but how does this concept work with nodes. Can anyone explain further what the textbook definition means?
- Thu Oct 18, 2018 5:19 pm
- Forum: Properties of Light
- Topic: Rydberg formula
- Replies: 8
- Views: 731
Re: Rydberg formula
Do we need to solve problems with the Rydberg formula? I remember that there is one equation we are not supposed to use in practice problems.
- Thu Oct 18, 2018 5:14 pm
- Forum: Einstein Equation
- Topic: Number of photons
- Replies: 7
- Views: 1062
Re: Number of photons
You divide the total energy by the energy per photon to get the number of photons.
- Tue Oct 16, 2018 5:23 pm
- Forum: Einstein Equation
- Topic: Question on Midterm
- Replies: 7
- Views: 900
Re: Question on Midterm
I would go with what is on the sheet. But at that point the numbers are on such a small scale where it won't really make a difference.
- Tue Oct 16, 2018 5:21 pm
- Forum: Einstein Equation
- Topic: Question on Midterm
- Replies: 7
- Views: 900
Re: Question on Midterm
I would go with what is on the sheet. But at that point the numbers are on such a small scale where it won't really make a difference.
- Tue Oct 16, 2018 4:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry Community Questions Due Date
- Replies: 7
- Views: 530
Re: Chemistry Community Questions Due Date
Yes, just to confirm it is due Sunday night by 11:59.
- Wed Oct 10, 2018 8:53 pm
- Forum: Balancing Chemical Reactions
- Topic: Seventh Edition- H21 [ENDORSED]
- Replies: 3
- Views: 491
Seventh Edition- H21 [ENDORSED]
I am having trouble with H21 in the seventh edition. We had to balance the eqn... C10H15N + O2--> CO2 + H2O + CH4N2O. The answer is 2C10H15N + 26O2--> 19CO2 + 13H2O + CH4N2O. Even though I have the answer, when I tried to do the problem myself, I had trouble getting to those numbers quickly. It took...
- Mon Oct 08, 2018 8:38 pm
- Forum: Limiting Reactant Calculations
- Topic: Question on Post-Module #22
- Replies: 2
- Views: 204
Question on Post-Module #22
After converting grams of C6H9Cl3 and AgNO3 to moles, I got 0.004 moles and 17.659 moles, respectively. After this step, I used the limiting reactant moles (C6H9Cl3) and converted it to grams of product (AgCl). The answer was 0.57328, but this was not close to the real answer. Does anyone know the s...
- Mon Oct 08, 2018 3:16 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Net Number Of Moles
- Replies: 5
- Views: 2335
Re: Net Number Of Moles
If you add up the total number of moles on the product side, and subtract by the total number of moles on the reactant side, you will get the net moles. While the number of moles on the product and reactant side may differ, the total number of atoms remain the same.
- Mon Oct 08, 2018 3:15 pm
- Forum: Properties of Light
- Topic: Intensity of Light and Wavelength
- Replies: 3
- Views: 152
Re: Intensity of Light and Wavelength
Amplitude is proportional with the intensity of the wave. If a wave has a higher amplitude it is more intense, and if it has a lower amplitude it is less intense.
- Mon Oct 08, 2018 3:09 pm
- Forum: Einstein Equation
- Topic: calculating kinetic energy
- Replies: 5
- Views: 318
Re: calculating kinetic energy
Mass will be in kg, because that is the standard SI unit!
- Thu Oct 04, 2018 2:24 pm
- Forum: SI Units, Unit Conversions
- Topic: pm to m
- Replies: 6
- Views: 891
Re: pm to m
If you memorize the prefixes, it will be helpful for so many problems. They are usually not given to you.
- Thu Oct 04, 2018 2:22 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Polyatomic ions
- Replies: 3
- Views: 170
Re: Polyatomic ions
It might help to look at patterns with suffixes, which will usually determine the number of oxygen atoms in the ion.
- Thu Oct 04, 2018 2:20 pm
- Forum: Limiting Reactant Calculations
- Topic: Significant figures in textbook 7th edition [ENDORSED]
- Replies: 5
- Views: 336
Re: Significant figures in textbook 7th edition [ENDORSED]
For significant figures, you should use the number of significant figures in the given. However, if there is more than one given with different significant figures, you use the one that has the least.
- Sun Sep 30, 2018 3:52 pm
- Forum: SI Units, Unit Conversions
- Topic: How does grading for discussion posts work?
- Replies: 80
- Views: 7645
Re: How does grading for discussion posts work?
Henri_de_Guzman_3L wrote:Is there a minimum number of posts/replies to get full points?
To get full points, you need to engage in this site three times. Otherwise, you will not get the full points.
- Sun Sep 30, 2018 3:50 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Accuracy vs Precision
- Replies: 23
- Views: 2555
Re: Accuracy vs Precision
I remember the example we used in class, but I am unsure how to tell which is which. One is when all measurements are close together, but not the desired amount? The other is when all the measurements are on target? Accuracy is how close your value is to the true/exact value. Precision is producing...
- Sun Sep 30, 2018 3:48 pm
- Forum: General Science Questions
- Topic: First Homework
- Replies: 3
- Views: 278
Re: First Homework
Anne Kim 3F wrote:When is our first homework assignment due? During our first discussion section or the Friday of week 1?
The first homework is due on Friday during week one. All other homeworks are going to be due during your discussion section in subsequent weeks!
- Sun Sep 30, 2018 3:42 pm
- Forum: SI Units, Unit Conversions
- Topic: How does grading for discussion posts work?
- Replies: 80
- Views: 7645
Re: How does grading for discussion posts work?
Does anyone know when our first homework assignment is due? Is it due on the Friday of week 1 during lecture or during our discussion in week 1? Also, I remember Professor Lavelle saying that we can "choose" our homework. Does that mean we can go through our textbook and choose the questi...