CHEMISTRY COMMUNITY

EllenRenskoff-1C

With the two elements given, figure out which one would form an acid and which one would form a base. For example, in part a, potassium would be in a basic compound because it is a group 1 metal, and bromine would be in an acidic compound because it forms an ionic compound with the H+ ion. Because p...

EllenRenskoff-1C

Is there a good way to tell just based on a molecular formula if a compound is amphoteric?

EllenRenskoff-1C

For an oxoacid, the rules would be slightly different as it is dependent on if the resulting anion is stabilized by delocalizing the negative charge. Basically, if the compound is Cl-O-H, it will be more acidic than I-O-H because it is more stabilized.The Cl is more electronegative than I, so it pul...

EllenRenskoff-1C

Yes, I believe those are examples of polydentates as those are ligands with 2, 3, 4, and 6 bonded atoms, respectively.

EllenRenskoff-1C

Based on the fact that these are compounds that involve the donating/ accepting of electrons, I would assume that we would primarily be using the word ligand to describe elements in an organometallic complex.

EllenRenskoff-1C

From my understanding, the difference between tetrahedral and square planar is related to their hybridization configurations. Additionally, I think that a square planar configuration is in one plane whereas tetrahedral is in multiple planes.

EllenRenskoff-1C

To my understanding hybridization is a rare process. Why would it be rare if it can make an atom exist at a lower energy state?

EllenRenskoff-1C

I think to find the bond order itself we would have to find the most stable Lewis structure to see what types of bonds are present in the given molecule.

EllenRenskoff-1C

I believe you would put the brackets around the entire ionic compound because the charge applies to the compound as a whole.

EllenRenskoff-1C

During lecture today (Friday), Professor Lavelle talked about the melting point of pentane vs. that of 2,2 dimethylpropane. He said that the molecule that is less tightly packed has a higher melting point. I am confused about why this would be, because intuitively the molecule that is more tightly p...

EllenRenskoff-1C

From my understanding, we would need to draw all of the resonance structures if asked because we would need to show that (for example) a double bond is not actually only between one pair but is actually spread throughout the molecule.

EllenRenskoff-1C

To my understanding, the point of resonance is that the double bond (or triple bond) is not necessarily shared only between two atoms but rather is equally distributed in the compound. If we are drawing resonance structures, we are showing that property. I think that problems will specify whether or...

EllenRenskoff-1C

Oxygen has a lower ionization energy than nitrogen because in the 2p orbital, oxygen has 4 electrons whereas nitrogen has 3. It is more stable for an element to have a half filled shell (as there are a total of 6 electrons that can occupy the 2p orbital), so therefore nitrogen would have a higher io...

EllenRenskoff-1C

I am confused about when we can add double bonds versus when we just add electrons to certain elements in the given compound to make the formal charge closer to zero. How would we know what the best way to do that is in order to draw the proper Lewis dot structure?

EllenRenskoff-1C

Do we need to take into account the fact that it says the work function is kJ*mol^-1? I know we have to convert the energy to J, but do we need to cancel out the moles?

EllenRenskoff-1C

Does that essentially mean that for multiplication and division we are basing the answer on the least number of sig figs present whereas for addition and subtraction we are basing it on the the least number of decimal places present?

EllenRenskoff-1C

When we are calculating an uncertainty using the Heisenberg Uncertainty Principle, how would we determine the proper amount of sig figs for our final answer? For example, if the uncertainty in velocity is +/- 0.5 m/s and the mass is 4.02 x 10^30 kg, would the final answer have one sig fig because th...

EllenRenskoff-1C

I got 3Cu + 8HNO3 -> 3Cu(NO3)2 + 2NO + 4H2O. I balanced the copper last because it was already balanced to begin with, so I knew that whatever coefficient was in front of the carbon on the reactants side would be the same as the coefficient on the products side for Cu(NO3)2. I tried to balance the h...

EllenRenskoff-1C

Just to clarify, is the equation En = -hR/ n^2 only used for calculating the change in energy levels for a hydrogen atom? I used this equation on the test, and I wanted to clarify that that was why this was wrong, since the question was asking about a multi-electron atom.

EllenRenskoff-1C

I believe that we will need to use correct sig figs for the midterm, and that the deduction for not using correct sig figs would be the same as for not putting units in our answer.

EllenRenskoff-1C

For metals, it is more likely that they would lose electrons and become a cation, and for gases, it is more likely that they would gain electrons and become an anion. So I think to answer the original question, it would depend on what type of element is in question to figure out which type of ion it...

EllenRenskoff-1C

From my understanding, the two parallel electrons can have the same spin because they occupy different orbitals, but if they are paired they are in the same orbital. So if they are in the same orbital, they must have opposite spins. I'm not really sure how this would work on the molecular level, tho...

EllenRenskoff-1C

How would the presence or absence of a nodal plane influence the electron configuration? Does that mean that the electrons are more evenly distributed in an orbital with nodal planes than in one without nodal planes?

EllenRenskoff-1C

On a related note, when we are showing the answer for a wavelength, should it always be in meters? For some questions in the solution manual, the final answer is written in nanometers. Does it matter which one we use for the final answer?

EllenRenskoff-1C

Regarding part D, I got that the wavelength was 8.8 nm from part C. Would this be considered part of the x ray and gamma ray radiation type even though the book says that's for wavelengths less than 3 nm? Is it because it its closer to that value than to the next type of radiation?

EllenRenskoff-1C

If h-bar is h/ 2*pi, where does the h/ 4*pi come from in the Heisenberg Indeterminancy Function come from?

EllenRenskoff-1C

Did Dr. Lavelle mention if it will be specified in the problem whether we are looking for energy per photon versus energy per mole of photon, or is it implied that it's per photon when we're talking about the photoelectric effect? (I hope my question makes sense.)

EllenRenskoff-1C

I believe it would be option A because the photoelectric experiment showed that the wavelength of light is equal to the ratio of the speed of light to the frequency.

EllenRenskoff-1C

Would classical mechanics be related to discrete variables? I remember that Dr. Lavelle was talking about the distinction between classical and quantum mechanics.

EllenRenskoff-1C

The answer key says that gamma rays have the highest energy, though in table 1.1 on pg. 4 it did not seem like there was enough information to distinguish whether x-rays or gamma rays have higher energy. How would we figure out which one has the higher amount of energy in a problem that's more gener...

EllenRenskoff-1C

Could you explain why option a is incorrect? I was confused about options a and c.

EllenRenskoff-1C

I would use Table 1.1, which is on pg. 4. I'm not sure if we have to memorize the wavelengths for each color on the visible light spectrum, but understanding this table should at least help with parts a and b of the question!

CHEMISTRY COMMUNITY

Search found 32 matches

Re: J.7 Select Acids and Bases

Re: Identifying an amphoteric compound

Re: Strength of an acid

Re: Polydentate

Re: Define Ligands?

Re: Tetrahedral and Square planar

Re: Hybrid Orbitals

Re: Bond Order

Re: 3.39 bracket question

Pentane vs. 2,2 Dimethylpropane

Re: 3.59 part c resonance structure? [ENDORSED]

Re: Resonance [ENDORSED]

Re: 3.33

Re: Formal Charge: Lewis dot structures

Re: 4b practice midterm

Re: diference in sig figs

Sig Figs in Heisenberg Uncertainty Principle

Re: balancing chemical reactions

Re: test 2 #4

Re: Use of sigfigs

Re: cation or anion?

Re: What does electron spin actually mean? [ENDORSED]

Re: Nodal Planes [ENDORSED]

Re: units for frequency and wavelength [ENDORSED]

Re: HW 1.33

Re: h-bar [ENDORSED]

Re: avogadro's number

Re: Post module quiz #25

Re: Equations in Quantum Mechanics [ENDORSED]

Re: HW 1.5 [ENDORSED]

Re: HW 1.3 [ENDORSED]

Re: Need help on 1.4