Search found 53 matches
- Sun Dec 08, 2019 11:06 pm
- Forum: Student Social/Study Group
- Topic: most stable
- Replies: 6
- Views: 562
Re: most stable
It doesn't necessarily mean that the molucule will be more stable, but molecules with more lone pairs will have smaller bond angles due to electron repulsion.
- Sun Dec 08, 2019 11:04 pm
- Forum: Air Pollution & Acid Rain
- Topic: Final Exam
- Replies: 5
- Views: 747
Re: Final Exam
The formula in the textbook was discussed in the box that was on the syllabus.
- Sun Dec 08, 2019 10:59 pm
- Forum: Administrative Questions and Class Announcements
- Topic: 14A FInal
- Replies: 6
- Views: 485
Re: 14A FInal
I believe scores will be posted in about two weeks but we pick up our physical exams the second week of winter quarter.
- Sun Dec 08, 2019 10:56 pm
- Forum: Student Social/Study Group
- Topic: Final
- Replies: 4
- Views: 430
Re: Final
It is similar to one of the questions that was reviewed in the final review session on Friday night.
- Sun Dec 08, 2019 10:52 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: OH- and H+
- Replies: 6
- Views: 532
Re: OH- and H+
Acids release H+ (hydronium) ions into the solution and bases release OH-(hydroxide) ions.
- Sun Dec 08, 2019 10:50 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Nitro vs Nitrito
- Replies: 6
- Views: 485
Re: Nitro vs Nitrito
It will be written as NO2 when it's nitro and ONO when it's nitrito.
- Mon Dec 02, 2019 12:03 am
- Forum: Amphoteric Compounds
- Topic: Memorizing Amphoteric Oxides
- Replies: 2
- Views: 190
Re: Memorizing Amphoteric Oxides
My TA said that we will need to be able to recognize it, but we will most likely not be given something ambiguous on the border of the diagonal.
- Mon Dec 02, 2019 12:01 am
- Forum: Lewis Acids & Bases
- Topic: Difference
- Replies: 4
- Views: 354
Re: Difference
We will need to be able to identify when a reactant is an acid, but my discussion was told it will not be ambiguous.
- Sun Dec 01, 2019 11:59 pm
- Forum: Conjugate Acids & Bases
- Topic: Conjugate Acids and Bases
- Replies: 4
- Views: 392
Conjugate Acids and Bases
Could someone explain exactly what it means when a product is a conjugate acid or base? Thank you!
- Sun Dec 01, 2019 11:55 pm
- Forum: Polyprotic Acids & Bases
- Topic: ligands
- Replies: 4
- Views: 429
Re: ligands
Ligands are Lewis bases. They have at least one pair of electrons that they donate to a metal atom/ion.
- Sun Dec 01, 2019 11:53 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Monday's Lecture
- Replies: 2
- Views: 216
Monday's Lecture
Will Dr. Lavelle be going over what he taught in lecture on Wednesday in lecture tomorrow?
- Mon Nov 25, 2019 12:27 am
- Forum: Administrative Questions and Class Announcements
- Topic: Week 9 Homework
- Replies: 2
- Views: 199
Re: Week 9 Homework
The only instructions on the syllabus are to do the homework on relevante topics so I assume molecular structure and acids and bases. Also Dr. Lavelle said we will be able to turn in both week 9 and week 10 homework during week 10.
- Mon Nov 25, 2019 12:18 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR formula
- Replies: 5
- Views: 308
Re: VSEPR formula
We will only need to be able to make comparisons to the bond angles discussed in class and understand why bond angles might be smaller or larger due to electron repulsion.
- Mon Nov 25, 2019 12:16 am
- Forum: Administrative Questions and Class Announcements
- Topic: Final Practice
- Replies: 3
- Views: 293
Re: Final Practice
I believe the TAs will hold review sessions for the final in which they go over past exam questions and explain the answers, but we have not been given access to a entire final exam and it’s answer key.
- Mon Nov 25, 2019 12:09 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Methanol's shape
- Replies: 1
- Views: 218
Re: Methanol's shape
It has two centers. The carbon is has tetrahedral electron geometry and tetrahedral molecular geometry. The Oxygen has tetrahedral electron geometry and bent molecular geometry.
- Mon Nov 25, 2019 12:03 am
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam
- Replies: 5
- Views: 285
Final Exam
What percentage of our grade is the final exam worth?
- Sun Nov 17, 2019 11:31 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Resonance and VSEPR
- Replies: 9
- Views: 535
Re: Resonance and VSEPR
No ! They don’t determine or change a molecules shape when drawing the VSEPER models.
- Sun Nov 17, 2019 11:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Repulsion Strength
- Replies: 5
- Views: 380
Re: Repulsion Strength
Lone pairs are close to each other than any other combination of pairs. Therefore lone -lone have the greatest repulsion strength.
- Sun Nov 17, 2019 11:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR Notation
- Replies: 4
- Views: 377
Re: VSEPR Notation
A = the central atom, X = an atom bonded to A, E = a lone pair on A.
- Sun Nov 17, 2019 11:07 pm
- Forum: Student Social/Study Group
- Topic: Bond Angles
- Replies: 6
- Views: 485
Re: Bond Angles
We just need to know comparisons, not exact bong angles.
- Sun Nov 17, 2019 10:47 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Hydrogen bonding
- Replies: 1
- Views: 168
Re: Hydrogen bonding
Since Hydrogen bonds are so strong, a greater amount of energy is needed to separate them. Thus molecules with hydrogen bonds typically have higher boiling / melting points.
- Sun Nov 10, 2019 9:58 pm
- Forum: Electronegativity
- Topic: Atom size
- Replies: 22
- Views: 3159
Re: Atom size
As you go up a group and across a period to the right, electronegativity increases. If you go down a group and to the left on the periodic table, atom size increases.
- Sun Nov 10, 2019 9:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: Electronegativity in between 1.5 and 2
- Replies: 2
- Views: 258
Re: Electronegativity in between 1.5 and 2
If this is the case you can’t conclude what type of bond it is. My TA said that we won’t be given something ambiguous.
- Sun Nov 10, 2019 9:51 pm
- Forum: Resonance Structures
- Topic: Drawing Resonance Structures
- Replies: 3
- Views: 250
Re: Drawing Resonance Structures
Yes, you draw all of the possible structures. This does not depict the real molecule but gets as accurate as possible with Lewis Structure diagrams.
- Sun Nov 10, 2019 9:49 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma vs Pi
- Replies: 11
- Views: 676
Re: Sigma vs Pi
Sigma bonds are formed by end-to-end overlapping of atomic orbitals and Pi bonds are when the lobe of one atomic orbital overlaps another
- Sun Nov 10, 2019 9:42 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bonding
- Replies: 6
- Views: 409
Re: Hydrogen Bonding
Hydrogen bonds are the strongest intermolecular bonds which is why water has such a high boiling point.
- Sun Nov 03, 2019 11:48 pm
- Forum: Lewis Structures
- Topic: Lewis Structures
- Replies: 3
- Views: 218
Re: Lewis Structures
You want to construct the bonds based on which structure results in the formal charges of each atom being closest to zero (unless you want a certain charge on the molecule)
- Sun Nov 03, 2019 11:46 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Manipulating for the initial energy level
- Replies: 2
- Views: 201
Re: Manipulating for the initial energy level
I find the first way more efficient, but as you said either way works.
- Sun Nov 03, 2019 11:41 pm
- Forum: Resonance Structures
- Topic: Bond lengths
- Replies: 11
- Views: 360
Re: Bond lengths
The structure represents it that way because it is the best we can do, but in reality there aren’t actually double and single bonds like that.
- Sun Nov 03, 2019 11:39 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Best Formal Charge
- Replies: 7
- Views: 441
Re: Best Formal Charge
You want the most electronegative atom to carry any extra negative charge and the least electronegative atom to carry any extra positive charge.
- Sun Nov 03, 2019 11:36 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal charge
- Replies: 16
- Views: 856
Re: Formal charge
You just want to get as close to 0 as possible.
- Sun Oct 27, 2019 6:03 pm
- Forum: Resonance Structures
- Topic: Ideal Lewis Structure
- Replies: 4
- Views: 175
Re: Ideal Lewis Structure
You can't represent the actual structure -- that is a limitation of lewis structure diagrams. Any of the resonance structures you draw will be considered correct.
- Sun Oct 27, 2019 6:00 pm
- Forum: Student Social/Study Group
- Topic: Midterm Length
- Replies: 7
- Views: 384
Re: Midterm Length
The midterm is 120 minutes long and worth 120 points.
- Sun Oct 27, 2019 5:59 pm
- Forum: Ionic & Covalent Bonds
- Topic: HW 2A.21d
- Replies: 5
- Views: 201
Re: HW 2A.21d
I am also confused about this question. I looked it up and the answer differs on various websites. Anyone who can clarify would be much appreciated!
- Sun Oct 27, 2019 5:50 pm
- Forum: Resonance Structures
- Topic: Determining Resonance Structures
- Replies: 6
- Views: 261
Re: Determining Resonance Structures
A molecule can have resonance structures when it has a lone pair or a double bond on the atom next to a double bond.
- Sun Oct 27, 2019 5:47 pm
- Forum: Properties of Electrons
- Topic: Formal Charge of an Atom
- Replies: 5
- Views: 294
Formal Charge of an Atom
Could someone explain how the formal charge is assigned to an atom? Thank you!!
- Sun Oct 27, 2019 5:27 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: placement of the negative sign on charges
- Replies: 4
- Views: 237
Re: placement of the negative sign on charges
The standard nomenclature for writing the charge of an ion says to follow the number with the sign i.e. 2+
- Sun Oct 20, 2019 11:20 pm
- Forum: Student Social/Study Group
- Topic: Midterm
- Replies: 17
- Views: 818
Re: Midterm
Yes I am pretty sure the the fundamentals covered in test 1 will also be on the midterm and final.
- Sun Oct 20, 2019 11:18 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Conceptual Understanding of Wave Function
- Replies: 2
- Views: 95
Re: Conceptual Understanding of Wave Function
To add to that a key concept Dr. Lavelle has pointed out many times is that orbitals are actually mathamatical equations; that will probably be helpful for the midterm.
- Sun Oct 20, 2019 11:07 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Question about electron configurations for multi electron atoms
- Replies: 2
- Views: 153
Re: Question about electron configurations for multi electron atoms
There is no way to figure this out on th spot — Dr. Lavelle said we just need to have those two exceptions memorized.
- Sun Oct 20, 2019 11:02 pm
- Forum: Einstein Equation
- Topic: energy emitted by H electrons
- Replies: 5
- Views: 202
Re: energy emitted by H electrons
I believe Dr. Lavelle mentioned we would be going over multi-electron atoms in the next lecture.
- Sun Oct 20, 2019 11:00 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: quantum numbers
- Replies: 2
- Views: 124
Re: quantum numbers
You might be given something like 4s2 and will have to find the four quantum numbers associated with that electron. N would be 4 and you would go off of that.
- Sun Oct 13, 2019 8:34 pm
- Forum: SI Units, Unit Conversions
- Topic: Percent Yield
- Replies: 6
- Views: 410
Re: Percent Yield
The actual value will be given to you in the question. From there the equation for percent yield is (theoretical/actual) x 100.
- Sun Oct 13, 2019 8:33 pm
- Forum: Properties of Light
- Topic: Electron energy levels
- Replies: 2
- Views: 92
Re: Electron energy levels
That is the case because the amount of energy released is discrete, not continuous. That means that only specific levels of energy can be emitted and no values in between. These specific values were represented by n=1, n=2, n=3, etc on the diagram in lecture.
- Sun Oct 13, 2019 8:25 pm
- Forum: DeBroglie Equation
- Topic: Constructive vs. Destructive Interference
- Replies: 5
- Views: 171
Re: Constructive vs. Destructive Interference
With constructive interference, is the resulting amplitude just the lengths of the individual waves added together? Or can it not be measured that way?
- Sun Oct 13, 2019 7:52 pm
- Forum: Properties of Light
- Topic: De Broglie's Equation
- Replies: 4
- Views: 196
Re: De Broglie's Equation
Also if it is helpful, Dr. Lavelle said in lecture that if your answer is smaller than x 10^-15 you can conclude the object does not exhibit wavelike properties.
- Sun Oct 13, 2019 7:12 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test 1 Grading
- Replies: 12
- Views: 917
Re: Test 1 Grading
Does anyone know when we are expected to get our test 1 scores back? Is it usually the following week in section?
- Sun Oct 13, 2019 7:09 pm
- Forum: Einstein Equation
- Topic: E=hv
- Replies: 8
- Views: 224
Re: E=hv
I understand how and when to use Planck's constant, but why do we use it? How was that specific number derived and what does it represent?
- Mon Oct 07, 2019 8:47 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: sig figs
- Replies: 20
- Views: 924
Re: sig figs
Will we be marked down on an exam for using the incorrect amount of sig figs in our answer?
- Mon Oct 07, 2019 8:45 am
- Forum: Limiting Reactant Calculations
- Topic: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
- Replies: 68
- Views: 6595
Re: Showing Work for Limiting Reactant Calculations on Tests [ENDORSED]
Are we going to be expected to know how to write the formula for something like "magnesium sulfate heptahydrate," for example, for the test in our discussions? Or will we just be given chemical symbols? I would check with your TA to be completely sure, but the information for the test fro...
- Mon Oct 07, 2019 8:37 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: sig figs
- Replies: 20
- Views: 924
Re: sig figs
After reading these posts I am confused about whether or not a zero is considered a sig fig if there is a number like 13.0
Since the zero is trailing the decimal point would it or would it not be a sig fig when doing arithmetic calculations?
Since the zero is trailing the decimal point would it or would it not be a sig fig when doing arithmetic calculations?
- Mon Oct 07, 2019 8:32 am
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Theoretical vs. Actual Yield
- Replies: 38
- Views: 13868
Re: Theoretical vs. Actual Yield
I understand the theoretical yield will always be greater than the actual yield due to substances sticking the the side of the beaker, etc, but are there ways to minimize or calculate this difference? And is it possible to have a theoretical yield that is exactly equal to the actual yield?
- Mon Oct 07, 2019 8:26 am
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student - Part II [ENDORSED]
- Replies: 298
- Views: 245048
Re: Advice from a Medical Student - Part II [ENDORSED]
Thank you so much for sharing. I am also thinking about Medical school -- as someone who has already gone through it, do you recommend doing anything specific as an undergraduate to make a Medical School application especially stand out? I know it is extremely competitive. Thank you again for your t...