Search found 53 matches

by AustinGrove3B
Fri Dec 07, 2018 5:13 pm
Forum: Administrative Questions and Class Announcements
Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Replies: 118
Views: 4123

Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]

Elle_Mendelson_4I wrote:Will someone please explain number 20?


Iron actually likes to have 6 bonds... coordination number 6. This Fe in the structure is bound to 4 nitrogens, but will also bind to a histine group and a structure that binds to oxygen, creating 6 bonds. 6 bonds creates an octahedral structure.
by AustinGrove3B
Fri Dec 07, 2018 5:11 pm
Forum: Administrative Questions and Class Announcements
Topic: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]
Replies: 118
Views: 4123

Re: FINAL PRACTICE - Lyndon's Churro Review Session [ENDORSED]

Elle_Mendelson_4I wrote:Will someone please explain 22


Myoglobin has one heme group, which is what that Fe N structure is. Each heme group can hold one oxygen, therefore myoglobin holds 1 oxygen. Hemoglobin has 4 heme groups.
by AustinGrove3B
Tue Dec 04, 2018 12:47 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configurations for ions
Replies: 2
Views: 64

Re: Electron Configurations for ions

For sulfur, it has two extra electrons because that would result in the sulfur atom having a full shell. For the Cd, it will give up two electrons because that will result in the 3rd shell being full... remember the configuration is ... 3d10 4s2
by AustinGrove3B
Tue Dec 04, 2018 12:44 pm
Forum: Naming
Topic: 9C.5 7th Edition
Replies: 2
Views: 41

Re: 9C.5 7th Edition

You would have to count the amount of electronegative atoms with lone pairs. The lone pair would form coordinate bonds with the metal. For the first question, there are 3 N in the equation, so it will form three bonds. H20 has one O, so it will form one bond. CO3 has two Os with lone pairs, so it ca...
by AustinGrove3B
Tue Dec 04, 2018 12:41 pm
Forum: Lewis Acids & Bases
Topic: Naming Acids
Replies: 2
Views: 60

Re: Naming Acids

There unfortunately is not just one way that I can tell you how to name acids. There are a set of rules, similar to the naming of a compound, that tell you what the name of the acid would be. They have rules for when the anion ends in ate vs ite etc.
by AustinGrove3B
Sat Dec 01, 2018 9:34 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: pi and sigma bonds
Replies: 3
Views: 66

Re: pi and sigma bonds

Yes. Double bonds and triple bonds cannot rotate. The single bond can rotate and is able to have 3-d structures. The double/triple bonded atoms will be in the same plane as each other.
by AustinGrove3B
Sat Dec 01, 2018 9:32 pm
Forum: Biological Examples
Topic: Heme structures
Replies: 1
Views: 45

Re: Heme structures

A heme group is an iron atom surrounded by 4 nitrogen atoms. Iron likes to have 6 bonds, so one of the other bonds is a massive histine group... but for biology, the most imoportant function of heme groups is the 6th bond--the oxygen. Heme groups are present in hemoglobin (in blood cells) and that i...
by AustinGrove3B
Sat Dec 01, 2018 9:28 pm
Forum: Lewis Acids & Bases
Topic: Lewis vs Bronsted
Replies: 2
Views: 21

Re: Lewis vs Bronsted

Lewis Acid: the molecule that accepts a lone electron pair
Lewis Base: the molecule that donates a lone electron pair

Bronstead Acid: Molecule that donates hydrogen ions
Bronstead Base: molecule that accepts hydrogen ions
by AustinGrove3B
Mon Nov 26, 2018 4:58 pm
Forum: Hybridization
Topic: 4.81
Replies: 1
Views: 24

Re: 4.81

I would be surprised if we had to draw lewis structures that were rings. They are common in organic chemistry, but that is much more complicated than the structures we have been drawing in class.
by AustinGrove3B
Mon Nov 26, 2018 4:56 pm
Forum: Hybridization
Topic: multiple bonds: pi and sigma bonds
Replies: 1
Views: 21

Re: multiple bonds: pi and sigma bonds

All of the molecules will have hybridized orbitals. You have to pick the one that best explains the structure.
by AustinGrove3B
Mon Nov 26, 2018 4:55 pm
Forum: Dipole Moments
Topic: TEST 3: Polarity
Replies: 7
Views: 100

Re: TEST 3: Polarity

I believe it is conventional to draw the dipole arrows towards the more electronegative atom... so the atom with the partial negative charge. I would probably recommend doing that on the test, especially because Dr. Lavelle did it that way.
by AustinGrove3B
Thu Nov 15, 2018 6:28 pm
Forum: SI Units, Unit Conversions
Topic: VSEPR model
Replies: 5
Views: 116

Re: VSEPR model

In other words, it is a model that explains how/why the molecules have the shape that they do. If you don't like the phrase VSEPR model, you could just think "molecular shape" instead. It is all the stuff we have done in class the last 2 days regarding trigonal planar, tetrahedral, octahed...
by AustinGrove3B
Thu Nov 15, 2018 6:26 pm
Forum: Hybridization
Topic: Question 4.31 6th Edition
Replies: 1
Views: 28

Re: Question 4.31 6th Edition

If you look up "VSEPR Structures" on the internet, it will show you which molecular shape corresponds to each of those. You likely are a little ahead in the homework compared to what we have gone over in class.
by AustinGrove3B
Thu Nov 15, 2018 6:24 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 6th Edition Hw #39
Replies: 1
Views: 24

Re: 6th Edition Hw #39

Because they do not actually have a bond. Remember that a bond in the molecular structure actually means they are sharing two electrons. But in this ionic compound, the Cl completely steals the electron. So they are attracted to each other because they are opposite charges (cation-anion), but are no...
by AustinGrove3B
Thu Nov 15, 2018 6:22 pm
Forum: Administrative Questions and Class Announcements
Topic: Thanksgiving Wednesday Class
Replies: 19
Views: 274

Re: Thanksgiving Wednesday Class

He said that if we are running on schedule, we will not have class Wednesday. But if we started to fall behind on molecular shapes, we would have to have class that day.
by AustinGrove3B
Sun Nov 11, 2018 4:04 pm
Forum: Ionic & Covalent Bonds
Topic: Van der Waals vs Dispersion Forces
Replies: 8
Views: 75

Re: Van der Waals vs Dispersion Forces

They are all interactions that give rise to attractive forces.
by AustinGrove3B
Sun Nov 11, 2018 4:02 pm
Forum: Dipole Moments
Topic: Solubility in Water
Replies: 5
Views: 97

Re: Solubility in Water

In general, molecules with bonds that have higher covalent character are LESS soluble in water. Molecules with bonds with low covalent character / high ionic character are MORE soluble in water. A good way to remember it is that salt, NaCl, is an ionic compound and is extremely easy to dissolve in w...
by AustinGrove3B
Sun Nov 11, 2018 3:59 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Hydrogen Bonding
Replies: 7
Views: 81

Re: Hydrogen Bonding

It is -20 kJ / mol. This is stronger than the dipole-dipole interactions, but not as strong as a full covelent/ionic bond.
by AustinGrove3B
Sun Nov 11, 2018 3:57 pm
Forum: Octet Exceptions
Topic: Number of electrons in relation to Octet
Replies: 3
Views: 39

Re: Number of electrons in relation to Octet

This usually happens to atoms like Boron, which only have 3 valence electrons. In the molecule BF 3 , there are 24 valence electrons. Boron will share its 3 valence to give the Fluorines a full octet, and that is a stable molecule. There will be 3 single bonds (octet for fluorines and 6 electrons to...
by AustinGrove3B
Sat Nov 03, 2018 9:19 pm
Forum: Lewis Structures
Topic: Cations and Anions
Replies: 3
Views: 38

Re: Cations and Anions

More specifically, cations are elements that have lost electrons, therefore having a positive charge. Anions are elements that have gained electrons, therefore having a negative charge.
by AustinGrove3B
Tue Oct 30, 2018 8:10 pm
Forum: Resonance Structures
Topic: Determining Bond Length
Replies: 2
Views: 43

Re: Determining Bond Length

The resonance structure will have an average bond length closer to the more "dominant" resonant structure... This will be the structure that has formal charges of the molecule closer to 0.
by AustinGrove3B
Tue Oct 30, 2018 8:04 pm
Forum: Trends in The Periodic Table
Topic: Electron Affinity
Replies: 2
Views: 45

Re: Electron Affinity

It has to do with the fact that when you add an electron to C, it goes in the 3rd P subshell (previously unoccupied). When you add an electron to N, it has to pair up with another electron in the p shell. The energy released in the C case is larger.
by AustinGrove3B
Tue Oct 30, 2018 8:02 pm
Forum: Lewis Structures
Topic: bond length
Replies: 2
Views: 36

Re: bond length

The lewis structures are just quick drawings of the shape of the molecule. You would not have to get detailed enough to show different bond lengths. The overall goal is to just show the relationship between the different atoms.
by AustinGrove3B
Sun Oct 28, 2018 9:34 pm
Forum: Trends in The Periodic Table
Topic: Horizontal Trend (Group 2 and Group 13)
Replies: 3
Views: 63

Re: Horizontal Trend (Group 2 and Group 13)

These are general trends that summarize the whole periodic table. They trends probably to not take into account every factor that would affect ionization energy. There are always exceptions
by AustinGrove3B
Sun Oct 28, 2018 9:31 pm
Forum: Lewis Structures
Topic: Dot's in the Lewis Structure
Replies: 10
Views: 116

Re: Dot's in the Lewis Structure

It does not matter. People usually tend to organize them so the unfilled sides match the other unfilled size, so geometrically they look like they should bind together. But it does not matter.
by AustinGrove3B
Sun Oct 28, 2018 9:30 pm
Forum: Trends in The Periodic Table
Topic: Electron configuration exceptions
Replies: 3
Views: 57

Re: Electron configuration exceptions

Having full or half full subshells is less potential energy than having semi full subshells. For that reason, sometimes electrons will be taken from the s subshell to fill the d subshell.
by AustinGrove3B
Tue Oct 23, 2018 4:24 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Homework Ch.2 Question 15, 6th Edition
Replies: 6
Views: 93

Re: Homework Ch.2 Question 15, 6th Edition

I think there would be 1 nodal plane in each p orbital. There are 3 orbitals in the p-block, so technically there would be 3 total nodal planes- 1 in each orbital.
by AustinGrove3B
Tue Oct 23, 2018 4:21 pm
Forum: Properties of Light
Topic: Atomic Spectra
Replies: 2
Views: 53

Re: Atomic Spectra

You do need to know all the fundamentals of this. Almost all of the math and equations we have been learning have actually all been related to the atomic spectra. All the equations with energy, bohr frequency condition, de broglie, rydberg equation etc all have applications with atomic spectra. Reme...
by AustinGrove3B
Tue Oct 23, 2018 4:18 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg & Bohr
Replies: 2
Views: 62

Re: Rydberg & Bohr

Ep = E2 - E1 where Ep is the energy of the photon, E2 is the energy of the excited electron, and E1 is the energy of the electron before excitation. In concert with our knowledge of E=hv, we can mathematically iterate this phenomenon known as Bohr's Frequency Condition that solves for the frequency ...
by AustinGrove3B
Tue Oct 23, 2018 4:14 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: orbital position
Replies: 2
Views: 100

Re: orbital position

Dr. Lavelle said in class that there is no required relation between a ml and the orbital. For example, when l=1 and ml = -1,0,1..... that would usually be read as p x , p y , and p z . But thats just because we read that from left to right. If you wrote ml= 1,0,-1 and had the order of p x , p y , a...
by AustinGrove3B
Wed Oct 17, 2018 5:12 pm
Forum: Photoelectric Effect
Topic: Atomic Spectra Post-Module Assessment
Replies: 1
Views: 35

Re: Atomic Spectra Post-Module Assessment

The total amount of energy is 11J. You calculated the amount of joules per photon to be 1.07 x 10-19. So dividing 11 by 1.07 x 10-19 gives the amount of photons.

Think about it this way: the amount of joules per photon x number of photons must = total joules
by AustinGrove3B
Wed Oct 17, 2018 4:42 pm
Forum: DeBroglie Equation
Topic: DeBroglie Equation
Replies: 2
Views: 37

Re: DeBroglie Equation

It can be applied to anything as small as electrons or something very large, such as a car. There is no restriction.

Having said that, the wavelength of a person or a car is so small that it is negligible. Only with very small objects like electrons will the wavelength be measurable.
by AustinGrove3B
Wed Oct 17, 2018 4:40 pm
Forum: Properties of Light
Topic: Series
Replies: 4
Views: 68

Re: Series

Dr. Lavelle said he does not require you to memorize information like constants and formulas. However, you should probably be familiar with the relative energies of each series, such as which series is visible light and which is uv-- so that you can kind of check your answer on a test to see if it m...
by AustinGrove3B
Wed Oct 17, 2018 4:39 pm
Forum: Properties of Light
Topic: Electromagnetic Radiation
Replies: 3
Views: 46

Re: Electromagnetic Radiation

The question is confusing because the "extent of the change" is a really weird way of saying the slope of the graph. It wants you to see what would happen to the slope of the wave when freq decreases (wavelength increases) and therefore slope decreases (less steep). Its just a poorly worde...
by AustinGrove3B
Wed Oct 17, 2018 4:22 pm
Forum: Properties of Light
Topic: Intensity of Light
Replies: 2
Views: 46

Re: Intensity of Light

Intensity of the light is directly proportional to the number of photons. So an intense light source will have more photons. Keep in mind that the intensity of the light has nothing to do with how much energy is in each photon (E=hv). In terms of the photoelectric effect, shining a high intensity, b...
by AustinGrove3B
Wed Oct 17, 2018 4:13 pm
Forum: Properties of Light
Topic: 1.17
Replies: 1
Views: 32

Re: 1.17

This is because for He +, z is equal to 2. So 2^2 =4. So the equation is 4 * R (energy difference). But I believe Dr. Lavelle said he would only test us on hydrogen, which has a z=1, so you can ignore that part of the equation.
by AustinGrove3B
Sun Oct 14, 2018 3:21 pm
Forum: Properties of Light
Topic: Colors and Frequency
Replies: 13
Views: 185

Re: Colors and Frequency

Its probably a good idea to just memorize the minimum and max frequency of the visible spectrum. But Dr. Lavelle insists he isnt going to make anybody memorize details such as that.
by AustinGrove3B
Sun Oct 14, 2018 3:18 pm
Forum: Administrative Questions and Class Announcements
Topic: Grades??
Replies: 4
Views: 93

Re: Grades??

Yeah Id assume the TA hands it back in discussion when they are done grading. I personally have not received any homework back yet.
by AustinGrove3B
Sun Oct 14, 2018 3:17 pm
Forum: Properties of Light
Topic: Wave vs. Particle Behavior
Replies: 5
Views: 53

Re: Wave vs. Particle Behavior

Electrons are always acting as both. They have a mass, which prove they are a particle. But they are also always moving in a wave like fashion (at a very small wavelength).
by AustinGrove3B
Sun Oct 14, 2018 11:55 am
Forum: Properties of Light
Topic: Speed of Light
Replies: 18
Views: 157

Re: Speed of Light

more specifically 2.99792 x 108. I think in the book they use this (more sig figs) than 3.0 x 108
by AustinGrove3B
Sun Oct 14, 2018 11:52 am
Forum: Ideal Gases
Topic: Reading the textbook [ENDORSED]
Replies: 81
Views: 25883

Re: Reading the textbook [ENDORSED]

The reading schedule is in the same outline as the homework problems. As a general rule, Dr. Lavelle tells us to read all the parts of the chapter that we are doing homework problems for.
by AustinGrove3B
Fri Oct 12, 2018 10:12 am
Forum: Photoelectric Effect
Topic: electron with no KE in reality
Replies: 2
Views: 39

Re: electron with no KE in reality

The energy would be enough to break the electron away from its atom, but it wouldnt be ejected away from it. So essentially it broke the electron's attraction to the atom but it is still there;.
by AustinGrove3B
Fri Oct 12, 2018 10:10 am
Forum: Administrative Questions and Class Announcements
Topic: How Should We Utilize Sampling
Replies: 3
Views: 90

Re: How Should We Utilize Sampling

I believe the Sapling Learning is optional. I think it gives you access to an online textbook and has some tutorials to help you with chemistry. But I am pretty sure that you do not have to do any mandatory assignments for the class on it
by AustinGrove3B
Fri Oct 12, 2018 10:08 am
Forum: General Science Questions
Topic: Exams.
Replies: 2
Views: 116

Re: Exams.

Everything is definitely given!! On test 1, you will see a big list of the formulas (I beleive that is actually the same formula sheet we will have on midterm/final if you wanted to see what was on it). I personally didnt even think the formula sheet was really needed for test 1. Professor Lavelle i...
by AustinGrove3B
Fri Oct 12, 2018 10:05 am
Forum: Properties of Light
Topic: Explaining answer for 1.3
Replies: 4
Views: 53

Re: Explaining answer for 1.3

The question is confusing because the "extent of the change" is a really weird way of saying the slope of the graph. It wants you to see what would happen to the slope of the wave when freq decreases (wavelength increases) and therefore slope decreases (less steep). Its just a poorly worde...
by AustinGrove3B
Fri Oct 12, 2018 10:02 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Balmer and Lyman series
Replies: 4
Views: 47

Re: Balmer and Lyman series

Essentially, they are important because they are the names of the major groups of spectral lines that Hydrogen gives off. The Balmer series is in the visible region of light, and the Lyman series is in the UV region of light. There are also other regions, such as the Pachen series in IR light, but t...
by AustinGrove3B
Thu Oct 04, 2018 11:14 pm
Forum: Molarity, Solutions, Dilutions
Topic: Q E27
Replies: 4
Views: 67

Re: Q E27

Find the weight of 1 mole of water. Remember each mole of a substance contains exactly 6.022*10^23 molecules of that substance. Therefore the weight of a mole of water divided by 6.022*10^23 would equal the weight of 1 water molecule.
by AustinGrove3B
Tue Oct 02, 2018 2:00 pm
Forum: Molarity, Solutions, Dilutions
Topic: E3 (sixth edition
Replies: 1
Views: 67

Re: E3 (sixth edition

You are correct that there are 9 Gallium molecules on the left. You do not know how many Astatine molecules you need to balance it. The simple way to do it is 210g mol / 70g mol =3. So each Astatine molecule will be 3 times as massive as each Gallium atom. Since there are 9 Gallium atoms, 3 Astatine...
by AustinGrove3B
Mon Oct 01, 2018 9:20 pm
Forum: SI Units, Unit Conversions
Topic: Homework written in pencil or pen?
Replies: 4
Views: 109

Re: Homework written in pencil or pen?

TA said pen is easier to read, but there is no requirement.
by AustinGrove3B
Mon Oct 01, 2018 9:18 pm
Forum: SI Units, Unit Conversions
Topic: Audio-Visual Focus-Topics, Assessments & Surveys
Replies: 10
Views: 188

Re: Audio-Visual Focus-Topics, Assessments & Surveys

TA told me that Dr. Lavelle actually meant to say he highly recommends doing the topics. They arent graded, but you are encouraged to do them.
by AustinGrove3B
Sun Sep 30, 2018 10:11 pm
Forum: Student Social/Study Group
Topic: 7 sets of problems?
Replies: 5
Views: 267

Re: 7 sets of problems?

He wants you to pick any 7 relevant questions to complete for your homework for that week, which you will usually turn in to your discussion section. In the back of the syllabus and in the chapter outlines, Dr. Lavelle gives you a bunch of relevant problems that you could chose from.
by AustinGrove3B
Sun Sep 30, 2018 10:05 pm
Forum: Administrative Questions and Class Announcements
Topic: Solutions Manual
Replies: 9
Views: 372

Re: Solutions Manual

The solutions manual has the answers to all the odd number questions in the book, which are also located in the back of the textbook. However, in the solutions manual, Dr. Lavelle explains how to get each answer and includes his work (which is definitely not in the back of the book). Its a good purc...
by AustinGrove3B
Sun Sep 30, 2018 9:58 pm
Forum: SI Units, Unit Conversions
Topic: Grams/mole
Replies: 12
Views: 235

Re: Grams/mole

Using g mol^ -1 can sometimes make your math a lot cleaner to look at, compared to writing it as ___ g / ___mol. If you divide g mol^-1 by another g mol^-1, it avoids having to write fractions inside of a fraction. Technically, doing that would be correct, but it would be really hard to interpret.

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