Search found 46 matches

by ariellasarkissian_3H
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: 7705

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?
by ariellasarkissian_3H
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: 63

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?
by ariellasarkissian_3H
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: 43

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?
by ariellasarkissian_3H
Wed Dec 05, 2018 1:42 pm
Forum: Naming
Topic: Anionic ligands
Replies: 5
Views: 124

Re: Anionic ligands

Did lavelle ever explicitly say that we had to memorize all the ligands on that worksheet?
by ariellasarkissian_3H
Tue Dec 04, 2018 8:06 pm
Forum: Lewis Acids & Bases
Topic: Acid but acidity is not due to its disassociation
Replies: 1
Views: 52

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!
by ariellasarkissian_3H
Wed Nov 28, 2018 6:17 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Week 8 Worksheet (3A3I3K)
Replies: 5
Views: 494

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?
by ariellasarkissian_3H
Mon Nov 26, 2018 3:54 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: test #3
Replies: 14
Views: 498

Re: test #3

Also, are we responsible for memorizing the bond angles for each shape?
by ariellasarkissian_3H
Mon Nov 26, 2018 3:32 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: CN- v O2 stability
Replies: 2
Views: 69

Re: CN- v O2 stability

does that also mean it is a stronger bond?
by ariellasarkissian_3H
Mon Nov 26, 2018 3:30 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: CN- v O2 stability
Replies: 2
Views: 69

CN- v O2 stability

Why is CN- more stable than O2?
by ariellasarkissian_3H
Wed Nov 21, 2018 3:28 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electron pair arrangement, actual structure
Replies: 3
Views: 58

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?
by ariellasarkissian_3H
Wed Nov 21, 2018 3:27 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Electron pair arrangement, actual structure
Replies: 3
Views: 58

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.
by ariellasarkissian_3H
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: 146

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 ...
by ariellasarkissian_3H
Thu Nov 15, 2018 3:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: bond angles with lone electrons
Replies: 2
Views: 76

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...
by ariellasarkissian_3H
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: 82

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?
by ariellasarkissian_3H
Mon Nov 12, 2018 5:41 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Net Number Of Moles
Replies: 5
Views: 1805

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.
by ariellasarkissian_3H
Mon Nov 12, 2018 5:40 pm
Forum: Administrative Questions and Class Announcements
Topic: Test 3 dates?
Replies: 11
Views: 360

Re: Test 3 dates?

Test 3 is the week after Thanksgiving so it shouldn't be a problem.
by ariellasarkissian_3H
Mon Nov 12, 2018 5:39 pm
Forum: Administrative Questions and Class Announcements
Topic: Step Up Sessions
Replies: 2
Views: 121

Re: Step Up Sessions

There were no sessions today. Dr. Lavelle sent out an email.
by ariellasarkissian_3H
Sun Nov 04, 2018 10:43 am
Forum: Octet Exceptions
Topic: Resonance Structures
Replies: 7
Views: 245

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...
by ariellasarkissian_3H
Sun Nov 04, 2018 8:15 am
Forum: Octet Exceptions
Topic: Adding a Double bond or leaving a lone pair [ENDORSED]
Replies: 3
Views: 108

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.
by ariellasarkissian_3H
Sat Nov 03, 2018 2:15 pm
Forum: Octet Exceptions
Topic: Which atom gets extra lone pair
Replies: 2
Views: 62

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?
by ariellasarkissian_3H
Sat Nov 03, 2018 2:15 pm
Forum: Octet Exceptions
Topic: Adding a Double bond or leaving a lone pair [ENDORSED]
Replies: 3
Views: 108

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?
by ariellasarkissian_3H
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: 28781

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?
by ariellasarkissian_3H
Mon Oct 22, 2018 9:01 pm
Forum: Properties of Electrons
Topic: Predicting Nodal Planes
Replies: 2
Views: 146

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...
by ariellasarkissian_3H
Mon Oct 22, 2018 7:09 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Concept Question on Study Guide
Replies: 1
Views: 73

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!
by ariellasarkissian_3H
Mon Oct 22, 2018 7:07 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Conceptual Question [ENDORSED]
Replies: 1
Views: 137

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...
by ariellasarkissian_3H
Sun Oct 21, 2018 3:20 pm
Forum: Trends in The Periodic Table
Topic: Test 2 Topics Covered Question
Replies: 2
Views: 88

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...
by ariellasarkissian_3H
Sun Oct 21, 2018 1:52 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: What is a node?
Replies: 2
Views: 38

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?
by ariellasarkissian_3H
Thu Oct 18, 2018 5:19 pm
Forum: Properties of Light
Topic: Rydberg formula
Replies: 8
Views: 137

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.
by ariellasarkissian_3H
Thu Oct 18, 2018 5:14 pm
Forum: Einstein Equation
Topic: Number of photons
Replies: 7
Views: 423

Re: Number of photons

You divide the total energy by the energy per photon to get the number of photons.
by ariellasarkissian_3H
Tue Oct 16, 2018 5:23 pm
Forum: Einstein Equation
Topic: Question on Midterm
Replies: 7
Views: 334

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.
by ariellasarkissian_3H
Tue Oct 16, 2018 5:21 pm
Forum: Einstein Equation
Topic: Question on Midterm
Replies: 7
Views: 334

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.
by ariellasarkissian_3H
Tue Oct 16, 2018 4:59 pm
Forum: Administrative Questions and Class Announcements
Topic: Chemistry Community Questions Due Date
Replies: 7
Views: 133

Re: Chemistry Community Questions Due Date

Yes, just to confirm it is due Sunday night by 11:59.
by ariellasarkissian_3H
Wed Oct 10, 2018 8:53 pm
Forum: Balancing Chemical Reactions
Topic: Seventh Edition- H21 [ENDORSED]
Replies: 3
Views: 298

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...
by ariellasarkissian_3H
Mon Oct 08, 2018 8:38 pm
Forum: Limiting Reactant Calculations
Topic: Question on Post-Module #22
Replies: 2
Views: 66

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...
by ariellasarkissian_3H
Mon Oct 08, 2018 3:16 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Net Number Of Moles
Replies: 5
Views: 1805

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.
by ariellasarkissian_3H
Mon Oct 08, 2018 3:15 pm
Forum: Properties of Light
Topic: Intensity of Light and Wavelength
Replies: 3
Views: 41

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.
by ariellasarkissian_3H
Mon Oct 08, 2018 3:09 pm
Forum: Einstein Equation
Topic: calculating kinetic energy
Replies: 5
Views: 82

Re: calculating kinetic energy

Mass will be in kg, because that is the standard SI unit!
by ariellasarkissian_3H
Thu Oct 04, 2018 2:24 pm
Forum: SI Units, Unit Conversions
Topic: pm to m
Replies: 6
Views: 363

Re: pm to m

If you memorize the prefixes, it will be helpful for so many problems. They are usually not given to you.
by ariellasarkissian_3H
Thu Oct 04, 2018 2:22 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Polyatomic ions
Replies: 3
Views: 70

Re: Polyatomic ions

It might help to look at patterns with suffixes, which will usually determine the number of oxygen atoms in the ion.
by ariellasarkissian_3H
Thu Oct 04, 2018 2:20 pm
Forum: Limiting Reactant Calculations
Topic: Significant figures in textbook 7th edition [ENDORSED]
Replies: 5
Views: 144

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.
by ariellasarkissian_3H
Sun Sep 30, 2018 3:52 pm
Forum: SI Units, Unit Conversions
Topic: How does grading for discussion posts work?
Replies: 80
Views: 2572

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.
by ariellasarkissian_3H
Sun Sep 30, 2018 3:50 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Accuracy vs Precision
Replies: 23
Views: 770

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...
by ariellasarkissian_3H
Sun Sep 30, 2018 3:48 pm
Forum: General Science Questions
Topic: First Homework
Replies: 3
Views: 152

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!
by ariellasarkissian_3H
Sun Sep 30, 2018 3:42 pm
Forum: SI Units, Unit Conversions
Topic: How does grading for discussion posts work?
Replies: 80
Views: 2572

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...

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