## Search found 56 matches

Sun Jan 10, 2021 5:17 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Sapling week 1 #2
Replies: 3
Views: 22

### Re: Sapling week 1 #2

Hi! To start this you would want to get the concentration of of SO3 in the beginning of the reaction (Initial). Dividing .780 mol/1.50 gets you .52 mol/L. This will be the initial concentration of SO3. The problem tells us that at equilibrium there is .160 mol of O2, converting that into concentrati...
Sun Jan 10, 2021 5:04 pm
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Water
Replies: 28
Views: 86

### Re: Water

Water is only included when it is a gas/ not a solvent. If it is a solid then it does not go in the ICE chart, and if it is a liquid it does not also because it would be acting as a solvent, and the change in concentration of the water in the reaction would be too small to be significant in the valu...
Sat Jan 09, 2021 8:18 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: K vs. Q
Replies: 53
Views: 142

### Re: K vs. Q

Yes Q is used at any time to see where the reaction is at in relation to equilibrium and K is the constant value at equilibrium. If Q=K then it is at equilibrium.
Sat Jan 09, 2021 8:11 pm
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Changing K
Replies: 4
Views: 25

### Re: Changing K

Physically speaking, temperature is the only way to change the K value because it causes favoring of either the products or reactants to be formed due the change. Doubling k and/or taking its inverse is more mathematical and is used when comparing reverse equations or equations that have been "...
Thu Jan 07, 2021 11:02 pm
Forum: Ideal Gases
Topic: Sapling Homework
Replies: 22
Views: 149

### Re: Sapling Homework

Sat Dec 12, 2020 8:32 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Prioritizing Polarizing Power of Polarizabilty
Replies: 3
Views: 20

### Re: Prioritizing Polarizing Power of Polarizabilty

Looking at the electronegativities helps as lower the difference the more covalent. However you can also look at the size, since S is the bigger than O it would create more covalent character as its distorted easier, and between the MgS and CaS options, Mg is closer to S incorporating the lower EN d...
Sat Dec 12, 2020 8:27 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: London Dispersion Force
Replies: 4
Views: 36

### Re: London Dispersion Force

London dispersion forces are also greater as the size of the atoms/molecules get bigger. The bigger atoms have higher polarizability, will become distorted more easily and create stronger London dispersion forces. This explains the difference in boiling points as well.
Sat Dec 12, 2020 8:22 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent/Angular Bond Angles
Replies: 5
Views: 34

### Re: Bent/Angular Bond Angles

Yes you are correct. If there is one lone pair (and 2 atoms) the electron geometry will be trigonal planar, however the molecular geometry is bent. Since it has 3 regions of e- density, the bond angles would be a little less than that of a trigonal planar with no lone pairs, so <120* If there are 2 ...
Sat Dec 12, 2020 8:08 pm
Forum: Properties of Light
Topic: wave properties of light
Replies: 4
Views: 33

### Re: wave properties of light

The electron diffraction of the crystal show the wave properties of electrons. The diffraction was shown in the slit experiment when the waves interfered with each other resulting in the light emission not hitting the other side exactly where the slits were, as expected if it were in the particle mo...
Thu Dec 10, 2020 11:31 am
Forum: Determining Molecular Shape (VSEPR)
Topic: Determining Shape
Replies: 10
Views: 95

### Re: Determining Shape

Agreeing with what everyone else has said, molecular shape is referring to the shape that is occupied by the atoms (bonds) while electron geometry refers to the shape created by all bonds and electrons. A central atom with 3 electron density regions would in essence have a trigonal planar electron g...
Sun Dec 06, 2020 4:48 pm
Forum: Hybridization
Topic: Pi Bonds Cannot Rotate
Replies: 23
Views: 149

### Re: Pi Bonds Cannot Rotate

They don't rotate because they are connected side by side, if one atom were to rotate they would no longer be side to side breaking the pi bond. Therefore, pi bonds keep a structure in its plane unless broken.
Sun Dec 06, 2020 4:46 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Lone Pair Locations
Replies: 6
Views: 55

### Re: Lone Pair Locations

Th lone pairs will be located in places where they have less interaction with other atoms since they repel them. In the see-saw shape for example, the lone pair would be located on one of the equatorial atoms since it would be repelling only 2 atoms (the axial atoms). If the lone pairs were on an ax...
Sun Dec 06, 2020 4:33 pm
Forum: Administrative Questions and Class Announcements
Topic: Will fundamentals problems be on our final?
Replies: 6
Views: 22

### Re: Will fundamentals problems be on our final?

I would think so because the final includes all the outlines and stuff we have learned although I don't think there will that many problems as compared to the other sections.
Sun Dec 06, 2020 4:29 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bond Angles
Replies: 13
Views: 88

### Re: Bond Angles

Whenever there are lone pairs, there is extra repulsion that repulses other bonds more greatly. This would cause the original bond angles to be less as they get closer together as a result of the lone pairs pushing them away.
Sun Dec 06, 2020 4:26 pm
Forum: Hybridization
Topic: How to simply determine hybridization
Replies: 27
Views: 181

### Re: How to simply determine hybridization

Hybridization is essentially the orbitals that represent the electron density regions. If there are 2 regions then the hybridization of the center atom will be sp, since there are two regions, 2 orbitals are accounted for. Just add up the s, p, and d until you get the number of regions. 3 regions is...
Sun Nov 29, 2020 3:54 pm
Forum: Hybridization
Topic: e density
Replies: 30
Views: 127

### Re: e density

Yes a lone pair is a region of electron density as well as a bonded pair. Single, double and triple bonds are all one region of electron density, but have diff numbers of pi and sigma bonds.
Sun Nov 29, 2020 3:52 pm
Forum: Resonance Structures
Topic: sapling 17 follow up question
Replies: 3
Views: 19

### Re: sapling 17 follow up question

okay, that makes sense. could someone give me an example of when sp3d hybridization would take place. It would happen when an atom has 5 electron density regions and is in period 3 or later, such as PCl5. P is in period 3 meaning it can have an expanded octet which includes the d-orbital. With its ...
Sun Nov 29, 2020 3:47 pm
Forum: Hybridization
Topic: delocalized pi bonds
Replies: 15
Views: 68

### Re: delocalized pi bonds

As others have said drawing out the lewis structure and determining if it has resonance will help to determine if it has delocalized pi bonds. HCN for example when drawn out shows C and N having a triple bond indicating it has 2 pi bonds. However HCN does not have resonance so the pi bonds are not d...
Sun Nov 29, 2020 1:23 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: VSEPR Chart
Replies: 18
Views: 102

### Re: VSEPR Chart

I think we do have to memorize the shape and the angles, although Lavelle said we won't necessarily be drawing them, we will still have to recognize them and apply them to problems.
Sun Nov 29, 2020 1:21 pm
Forum: Student Social/Study Group
Topic: How to study for class
Replies: 30
Views: 171

### Re: How to study for class

I watch out for conceptual details from lecture, and read through the textbook to solidify them and find the textbook problems to be really helpful since they are worded similarly to the exams.
Sun Nov 22, 2020 4:49 pm
Forum: Ionic & Covalent Bonds
Topic: Covalent Character
Replies: 33
Views: 194

### Re: Covalent Character

Covalent character for covalent bonds is how low the difference in electronegativity is, the lower it is the more covalent. In terms of ionic bonds, the more polarizable the anion, the more easily distorted it is so its pulled closer to the cation. The larger the anion (polarizable), and smaller the...
Sun Nov 22, 2020 4:37 pm
Forum: Bond Lengths & Energies
Topic: Bond Length vs Size of Molecule
Replies: 14
Views: 121

### Re: Bond Length vs Size of Molecule

The atomic size would effect bond strength in covalent bonds as the bigger the atom the larger the distance between the two the weaker the bond. This is talking about the bond between individual atoms. The boiling point is referring to intermolecular forces between molecules, so CH4 interacting with...
Sun Nov 22, 2020 4:31 pm
Forum: Resonance Structures
Topic: Resonance Structures and Energy
Replies: 21
Views: 96

### Re: Resonance Structures and Energy

The lewis structure with the lowest amount of energy will always be favored as it is the stablest. The structure with formal charges all equal to zero, or if that isn't an option, the structure with the most amount of atoms with a 0 charge and the central atom having its lowest possible formal charg...
Sun Nov 22, 2020 4:28 pm
Forum: Student Social/Study Group
Topic: Study Tips for Final Exam
Replies: 57
Views: 392

### Re: Study Tips for Final Exam

Something that has helped me is creating a list of all the topics we have covered, and redoing the textbook problems/modules that go with it. For topics you feel you have a better grasp of, do a few questions, but focus on the more challenging topics so that you can feel confident on all of topics a...
Tue Nov 17, 2020 6:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Textbook question 2A.3
Replies: 2
Views: 12

### Re: Textbook question 2A.3

The 3+ means that the atoms are more positive, meaning they lost electrons (which are negative). Since As lost 3 e- that leaves the 4s and 3d orbital still filled as the three electrons in the p orbital were removed. The same goes for Ge with its 2 electrons removed. When removing electrons they are...
Sun Nov 15, 2020 5:19 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic v. Covalent Bonding
Replies: 16
Views: 121

### Re: Ionic v. Covalent Bonding

Ionic bonds tend to be between s and p block elements. This is because of the bigger difference in electronegativity. The larger the difference in electronegativity, the more likely it is ionic. The smaller the difference, and the closer together the elements are on the periodic table, the more they...
Sun Nov 15, 2020 5:14 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration Exceptions?
Replies: 5
Views: 25

### Re: Electron Configuration Exceptions?

3d would come before 4s because once 3d starts getting filled, it has lower energy than 4s. Other exceptions taught during lecture were Chromium being written as [Ar] 3d5 4s1 instead of [Ar] 3d4 4s2 because it is more stable having its orbitals "half full" as opposed to having one orbital ...
Sun Nov 15, 2020 5:07 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Which has more ionic character?
Replies: 11
Views: 82

### Re: Which has more ionic character?

can anyone give a general definition of what ionic character is? And how exactly do you rank them? Ionic character essentially( in the context of covalent bonds ) is the covalent bonds characteristic of not having electrons equally shared/being polar. Covalent character means (in the context of ion...
Sun Nov 15, 2020 4:52 pm
Forum: Quantum Numbers and The H-Atom
Topic: Textbook 1D#17
Replies: 3
Views: 31

### Re: Textbook 1D#17

The magnetic quantum numbers (ml) are the orbitals in a subshell. Essentially ml is equal to the positive and negative values of l and the numbers in between. [ l, l-1..., -l] l=subshell shape( l=0 is s),( l=1 is p),(l=2 is d),( l=3 is f) s subshell (l=0) ml= 0 p subshell (l=1) ml= -1,0,1 d subshell...
Sun Nov 15, 2020 4:28 pm
Forum: Lewis Structures
Topic: Lewis acids and Bases
Replies: 20
Views: 119

### Re: Lewis acids and Bases

To help classify them you would have to draw out the lewis structure. The molecule/compound that does not have a complete octet will readily accept electrons making it the acid. The molecule with lone pairs able to give away will be the base. Like the example during one of the lectures, BF3 drawn ou...
Sun Nov 15, 2020 4:21 pm
Forum: Dipole Moments
Topic: London Dispersion forces
Replies: 14
Views: 75

### Re: London Dispersion forces

Yes all molecules have London dispersion forces, and it is one of the weakest intermolecular forces. When two molecules come in close proximity they "induce" a partial negative/positive on each other instantaneously making it temporary.
Sun Nov 08, 2020 2:23 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge of the Same Element
Replies: 15
Views: 60

### Re: Formal Charge of the Same Element

The formal charge of the same element can differ based on the amount of bonds it has and the number of valence electrons as those numbers would result in varying charges when plugged into the formal charge formula. To be safe try to find the formal charge of all atoms of the element, even if they ar...
Sun Nov 08, 2020 2:13 pm
Forum: Administrative Questions and Class Announcements
Replies: 6
Views: 37

Each post you make counts for 1 point, you can make up to five points per week which equates to 50 points for 10 weeks. Your 5 posts must be made within the given week before midnight Sunday to get the credit as they don't carry over and you can only get a maximum of 5 points per week.
Sat Nov 07, 2020 8:45 pm
Forum: Electronegativity
Topic: Electronegativity Table/Chart in Lecture
Replies: 14
Views: 53

### Re: Electronegativity Table/Chart in Lecture

We don't need to memorize it but having a general idea of the trend and its relation to ionization energy is helpful. If we need the numbers, the chart will be provided on problems that need it.
Sat Nov 07, 2020 2:12 pm
Forum: Student Social/Study Group
Topic: Favorite TV shows
Replies: 176
Views: 823

### Re: Favorite TV shows

Some new shows on Netflix called The Queens Gambit and Grand Army are really good I recommend watching them! Some of my favs are new girl, criminal minds and Pose.
Sat Nov 07, 2020 1:52 pm
Forum: Ionic & Covalent Bonds
Topic: Electron Affinity vs. Electronegativity
Replies: 12
Views: 59

### Re: Electron Affinity vs. Electronegativity

Electron affinity is measurable and shows the amount of energy released or absorbed when adding an e- to an atom, whereas, according to my TA, electronegativity is more of a scale without a set measure that describes the ability of the atom to attract/pull electrons.
Sun Nov 01, 2020 2:23 pm
Forum: Quantum Numbers and The H-Atom
Topic: wavelength
Replies: 13
Views: 79

### Re: wavelength

Wavelength can not be negative as it is a measurement, having a negative value in this context would not be applicable.
Sun Nov 01, 2020 2:17 pm
Forum: Properties of Light
Topic: How to remember what v is in equations
Replies: 46
Views: 241

### Re: How to remember what v is in equations

E=hv and[ C=lamba x v ]is relating to energy and wave properties of light, so v in the different font would be frequency. In de Brogiles equation and kinetic energy equation they deal with speed/motion of particles in some way so v would symbolize velocity.
Sun Nov 01, 2020 2:07 pm
Forum: Student Social/Study Group
Topic: Tips for Staying Focused
Replies: 52
Views: 508

### Re: Tips for Staying Focused

A good tip is to reward yourself with something after doing any amount of work you feel you can accomplish and are actually motivated to do in a certain time period. After you are done you can watch an episode of your favorite show, or what I like to do is play among us to de-stress :)
Sun Nov 01, 2020 11:50 am
Forum: Ionic & Covalent Bonds
Topic: Homework due date
Replies: 49
Views: 332

### Re: Homework due date

I think all homeworks are due Sunday night at midnight of the corresponding week they are due.
Sun Nov 01, 2020 11:44 am
Forum: Properties of Light
Topic: Is c always the speed of light?
Replies: 88
Views: 446

### Re: Is c always the speed of light?

Yes c will always be the speed of light as its a constant. C=wavelengthxfrequency
Sun Oct 25, 2020 7:03 pm
Forum: Student Social/Study Group
Topic: Midterm Prep
Replies: 15
Views: 99

### Re: Midterm Prep

Constance Newell wrote:do yall know how long we have?

We have the whole discussion time which is around 50 minutes, my TA said if a little extra time is needed it will be provided.
Sun Oct 25, 2020 5:43 pm
Forum: Einstein Equation
Topic: m vs nm
Replies: 66
Views: 432

### Re: m vs nm

Since the exam will be multiple choice I would look at the units offered through the answers, if its in nm then just convert the answer found in m to nm if necessary.
Sun Oct 25, 2020 2:56 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm calculator policy
Replies: 10
Views: 65

### Re: Midterm calculator policy

I don't think there are any restrictions, my TA said the use of graphing calculators is ok.
Thu Oct 22, 2020 5:03 pm
Forum: Properties of Light
Topic: Textbook Question 1.A.9
Replies: 4
Views: 50

### Re: Textbook Question 1.A.9

To match each type of radiation to the event you have to look at the wavelengths you get for each row in the chart. You would then match the event to the wavelength they correspond with. For example, since reading is looking at visible light which is within the range of 400-720nm that event would go...
Wed Oct 21, 2020 10:33 pm
Forum: Properties of Light
Topic: Wavelengths in Light Spectrum
Replies: 9
Views: 78

### Re: Wavelengths in Light Spectrum

It would be good to know the order in regards to questions regarding wavelength. For example, knowing that Radio waves have the longest wavelength and then below that comes infrared(nm are in the 1000s), then visible light (720-400nm) and UV has shorter wavelengths with 400nm and below. I have seen ...
Sun Oct 18, 2020 12:23 pm
Forum: Administrative Questions and Class Announcements
Topic: Midterm Exam Format
Replies: 14
Views: 94

### Re: Midterm Exam Format

Closed book means that we don't get to use our notes during the test, however we do get access to the periodic table and a sheet of constants and equations I believe. Since we will be taking it with our TAs, they will be monitoring our workspace as well to see if we are testing fairly.
Fri Oct 16, 2020 2:14 pm
Forum: Empirical & Molecular Formulas
Topic: When Empirical Formula and Molecular Formula are the Same
Replies: 4
Views: 35

### Re: When Empirical Formula and Molecular Formula are the Same

If the empirical and molecular formula are the same, that means that the empirical formula found is actually the molecular formula. This would be the case if the molar mass of the empirical formula found is the same as the molar mass of the molecule/compound given to you. If you were to divide the M...
Fri Oct 16, 2020 2:10 pm
Forum: Photoelectric Effect
Topic: When are electrons excited vs ejected
Replies: 16
Views: 128

### Re: When are electrons excited vs ejected

Electrons are excited when energy from the photon is present but does not exceed the threshold/work function resulting in the electrons to jump energy levels (excited). The electron is ejected when the amount of energy exceeds the threshold/work function.
Fri Oct 16, 2020 2:06 pm
Forum: Einstein Equation
Topic: Equation Sheet
Replies: 15
Views: 131

### Re: Equation Sheet

Yes I think we will be provided an equation sheet and some constants etc. will be provided in questions too. If you go to the class website he has a document with constants and equations that you can access.
Tue Oct 13, 2020 11:23 am
Forum: Empirical & Molecular Formulas
Topic: Empirical or Molecular
Replies: 11
Views: 110

### Re: Empirical or Molecular

To find out if the formula is the molecular one, you would need to find the mass of the current empirical formula you found and compare it to the given Molar mass of the compound/molecule in question. If it is not equal, then that means the formula you created is empirical. To find the molecular for...
Thu Oct 08, 2020 11:30 am
Forum: Molarity, Solutions, Dilutions
Topic: G5
Replies: 8
Views: 108

### Re: G5

After finding the molarity, you use it to find the molarity of the compound or element you are trying to find the volume for. For A )that would be Na+. Looking at the compound in the solution which is sodium carbonate Na2(CO3) you see that Na has a subscript of 2 so the amount of mols of the compoun...
Tue Oct 06, 2020 5:08 pm
Forum: Significant Figures
Topic: 5000 vs 5000.0
Replies: 7
Views: 89

### Re: 5000 vs 5000.0

Yes that is correct. The decimal makes the zeros significant. If you were to have 0.05000, it would have 4 sigs figs as the decimal makes all the zeros to the right of the 5 significant, while the zero to the left is not. With decimals less than one the only 0s that are significant figures are ones ...
Tue Oct 06, 2020 4:58 pm
Forum: Molarity, Solutions, Dilutions
Topic: Volume in Molarity Equations
Replies: 5
Views: 46

### Re: Volume in Molarity Equations

Since molarity has units mol/L, the v would have to be in Liters to be able to cancel out units of volume (L) in the problem and/or end up with a molarity that is mol/L. If the problem gives mL you have to convert to L to solve and, if needed, convert back to mL once finished.
Tue Oct 06, 2020 4:54 pm
Forum: SI Units, Unit Conversions
Topic: Fundamentals E. 1
Replies: 2
Views: 48

### Re: Fundamentals E. 1

To put it into simpler terms, the problem is asking what the length of the fibers would be. We are given that 1.00 mol of Ag atoms make up that length so we just need to figure out the diameters of the atoms and multiply that by the total amount of atoms in orders to get the length. First we would g...
Mon Oct 05, 2020 2:22 pm
Forum: Balancing Chemical Reactions
Topic: Periodic Table
Replies: 50
Views: 480

### Re: Periodic Table

The periodic table includes the element symbol and atomic weight, I believe we are allowed to have a periodic table out during tests, so you don't need to memorize all the symbols as they are there. It'd be good to start getting familiar with the symbols though as knowing them can help solve problem...