CHEMISTRY COMMUNITY

ariaterango_1A

The roman numerials represent the oxidation number of the transition metal.

ariaterango_1A

Does anyone have a good tactic for memorizing the names of ligands?

ariaterango_1A

How do we tell if a molecule is polydentate?

ariaterango_1A

Do we need to know the formula for EDTA for this test?

ariaterango_1A

Does anyone know what the ratio of subjects will be on the final exam? For example, I know the exam will cover all major topics however, will it be more on the topics we haven't been tested on?

ariaterango_1A

What is the difference between intermolecular and intramolecular bonding?

ariaterango_1A

Yes, he just updated this on his class website today under "Final Exam: Review Sessions and Exam Venues."

ariaterango_1A

Does anyone currently have the grades for the weekly discussion posts in their gradebook? Mine currently says N/A, I have been persistent about doing 5 posts a week, but it still scares me not knowing my current progress.

ariaterango_1A

Yes the coordination number is determined by the # of atoms bonded directly to the central atom. If an atom is polydentate, take that into account when calculating this number. For instance if a bond is bidentate make sure to multiply that bond by 2 when calculating the coordination number.

ariaterango_1A

What is exactly the inductive effect and how does it help to determine strong acids/bases vs weak acids/bases?

ariaterango_1A

Should we memorize strong acids and bases for the final??

ariaterango_1A

You can tell by looking at the periodic table... metal oxides for bases, nonmetal oxides form acids, and the elements Pb, Bi, Sn, In, Ga, Al, Be, Ge, As, and Sb as oxides form amphoteric (both an acid and a base). Hope this helps!

ariaterango_1A

As many students have stated molar mass and boiling point are directly proportional. When it comes to intermolecular forces, London dispersion forces increase with larger molecules thus increasing the boiling point. Hope this helps!

ariaterango_1A

Do we need to know how to find the composition of each bond and lone pair in the form sigma( ) and pi ( )?

ariaterango_1A

I believe by saying the S character increases, the s orbital is becoming prominent. So sp (one has 2 hybridized orbitals, one s and one p) has a larger bond angle than sp2 (which has 3 hybridized orbitals, 1 s and 2 p). etc. Hope this helps!

ariaterango_1A

For naming I believe you just need to know the ligands in the table 9C.1. Hope this helps!

ariaterango_1A

I just had lecture and Dr. Lavelle stated that all the concepts covered in class since the midterm will be on test #2, except hybridization. Hope this helps!

ariaterango_1A

Electron geometry/ arrangement describes the number of bonding regions. For example: NH3 the electron geometry/ # of bonding regions is 4 or tetrahedral, however since there is one lone pair the shape/molecular geometry would be described as trigonal pyramidal. Hope this helps!

ariaterango_1A

You should know the differences pi and sigma bonds form in orbital overlap. Pi bonds form side-to-side while sigma bonds form end to end. Additionally, single bonds are made up of one sigma bond, double bonds are made up of one sigma and one pi bond, and triple bonds are made up of one sigma and two...

ariaterango_1A

Dr. Lavelle just clarified in class today that test #2 will cover everything since the midterm: VSEPR, intermolecular forces, pi and sigma bonding, ionic vs covalent, and polarity. No hybridization will be on this test! Hope this helps!

ariaterango_1A

What is the best way to tell which bonds are more covalent or ionic in character?

ariaterango_1A

Past students said the test contained periodic trends, lewis dot, and radicals, but I am unsure if it is the same this year. Please, someone clarify which homework sections this test will cover. Thank you!!

ariaterango_1A

Do we need to memorize the boiling and melting points of each type of interaction? Also which interaction has the greatest energy and therefore has the highest melting and boiling point? Thank you!

ariaterango_1A

Are we primarily focusing on dipole-dipole, london dispersion, and hydrogen bonding in this class?? The homework sections are 3F.4 and 3F.5, which only cover these topics.

ariaterango_1A

Polar bonds mean that there is electronegativity difference, and nonpolar bonds don't have an electronegativity difference, like N2. Hope this helps!

ariaterango_1A

Hi! What topics will be covered in this next test?

ariaterango_1A

For this exam do we need to know extensive detail on the concepts of Lewis acids and bases and coordinate covalent bonds??

ariaterango_1A

I believe you can always convert to scientific notation as long as the correct # of sig fig's is satisfied. Additionally, scientific notation is a much simpler way of writing very small numbers such a 4.76 x 10^-18. For me, converting to scientific notation has eliminated errors such as forgetting a...

ariaterango_1A

I was planning on attending tonight's chemical bonding review session. Does anyone know when he will be rescheduling this?

ariaterango_1A

Hi! I am confused on what we need to know about Schrodinger's Equation and what the major concept is behind it?

ariaterango_1A

I thought I heard that Bohr's frequency equation won't be provided on the constants sheet. Is this true?

ariaterango_1A

Hi! What materials are needed for this first midterm exam?

ariaterango_1A

Thank you everyone! I didn't realize we would be provided a list of constants. It would be a good idea for me to do the practice problems with this sheet to cancel out units.

ariaterango_1A

Hi! Would you be able to post answers to these questions in a couple days?

ariaterango_1A

Yes, correct. Electrons that are in the first energy level (energy level 1) are closest to the nucleus and will have the lowest energy. Electrons further away from the nucleus will have higher energy. However, remember as you go down a group the ionization energy decreases because it is easier to ta...

ariaterango_1A

I saw today there are review sessions for fundamentals and early quantum. Since I can't make these today do you think he will be holding other sessions on these same topics??

ariaterango_1A

Hi! I was wondering what subjects will be covered on the midterm? Fundamentals, Quantum, and Chemical bonds? Thank you!

ariaterango_1A

Does anyone know if for the midterm we will be provided the wavelength (nm) corresponding to each light on the spectrum, or if we have to memorize these? Thank you!

ariaterango_1A

So for this question you know that the d orbital corresponds to l=2. And for that reason there are four values of ml: -2,-1,0,1,2. Hope this helps!

ariaterango_1A

Hi! I was wondering what the conceptual differences are between n,l,ml,and ms. Which is considered the orbital, the shell, or the subshell? Thank you!

ariaterango_1A

Hi! Does anyone know how to tell the difference between an electron configuration of the ground state and the electron configuration of an excited state? One of the homework problems in section E pertains to this.

ariaterango_1A

I'm having trouble with units when conducting some of these problems. Could anyone help me with the units of velocity, threshold energy, Plank's constant, and frequency?

ariaterango_1A

Hi! So the uncertainty equation states that uncertainty in momentum (delta p) * the uncertainty in position (delta x) is greater than or equal to h/4pi. So first we convert 350 pico-meters to meters which is your delta x. Then you calculate (6.626 x10^-34)/ (4)*(3.14)*(350 x10^-12m) to find the unce...

ariaterango_1A

Hi! So for part c you first use the photo electric effect equation where E(photon)-threshold energy= kinetic energy (1/2 mv^2). After calculating this you find your energy of a photon, but since it asks for wavelength you plug this energy into the equation E=h*v to find v or frequency and use this f...

ariaterango_1A

Hi! I believe this is because Ultraviolet light lies within the Lyman Series which ends at n=1. Hope this answers your question.

ariaterango_1A

Hi could someone help me with the set up of 1B.9? "A lamp rated at 32W (1W=1J.s^-1) emits violet light of wavelength 420nm. How many photons of violet light can the lamp generate in 2.0s? How many moles of photons are emitted in that time interval?

ariaterango_1A

Hi,
I was wondering if Homework 3 (due during discussion in week 4) is only on chemical bonds, or both quantum and chemical bonds?
Thank you!

ariaterango_1A

Thank you both. I will bring a pen and scientific calculator to discussion.

ariaterango_1A

To find the excess in the first reaction do you compare the molar ratios of the reactants to each other? For instance, .047 moles of P4 * (3 mol of O2/ 1 mol of P4) and .18 moles of O2 * (1mol of P4/ 3 mol of O2) ? From there I found that P4 is limiting and oxygen is in excess so you would subtract ...

ariaterango_1A

I have my test tomorrow in discussion. Do we need to write our answers in pen? I want to be prepared with the right material tomorrow.

ariaterango_1A

A reaction vessel contains 5.77g of white phosphorous and 5.77 g of oxygen. The first reaction to take place is the formation of phosphorous (III) oxide, P4O6: P4+ 3O2 -> P4O6. If enough oxygen is present, the oxygen can react further with this oxide to produce phosphorous (v) oxide, P4O10: P4O6 + 2...

ariaterango_1A

I emailed my TA and received confirmation that we don't need to purchase as blue book and that everything will be provided in discussion.

ariaterango_1A

What resources are you going to use to study for this initial test?

ariaterango_1A

Thank you all. I will now be able to simplify my studying.

ariaterango_1A

Does anyone know if this first test includes the properties of light or if it is just the review of fundamentals/high school chemistry?

ariaterango_1A

Hello! In my experience it has been helpful to do all the problems so you can be exposed to as many concepts and ways of phrasing questions as possible. Hope this helps!

ariaterango_1A

What an incredible story! Thank you for sharing. Was your path to achieving your pre-med degree at UCLA difficult? Do you have any advice for a second year like me following a similar path? Thank you!!

Search found 57 matches