Search found 32 matches

by EllenRenskoff-1C
Fri Jun 08, 2018 6:06 pm
Forum: Bronsted Acids & Bases
Topic: J.7 Select Acids and Bases
Replies: 1
Views: 225

Re: J.7 Select Acids and Bases

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...
by EllenRenskoff-1C
Thu Jun 07, 2018 9:54 pm
Forum: Amphoteric Compounds
Topic: Identifying an amphoteric compound
Replies: 3
Views: 522

Re: Identifying an amphoteric compound

Is there a good way to tell just based on a molecular formula if a compound is amphoteric?
by EllenRenskoff-1C
Wed Jun 06, 2018 5:27 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Strength of an acid
Replies: 14
Views: 510

Re: Strength of an acid

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...
by EllenRenskoff-1C
Mon Jun 04, 2018 8:04 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 5
Views: 155

Re: Polydentate

Yes, I believe those are examples of polydentates as those are ligands with 2, 3, 4, and 6 bonded atoms, respectively.
by EllenRenskoff-1C
Sat Jun 02, 2018 4:25 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Define Ligands?
Replies: 10
Views: 274

Re: Define Ligands?

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.
by EllenRenskoff-1C
Fri Jun 01, 2018 9:48 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Tetrahedral and Square planar
Replies: 8
Views: 360

Re: Tetrahedral and Square planar

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.
by EllenRenskoff-1C
Wed May 30, 2018 3:12 pm
Forum: Hybridization
Topic: Hybrid Orbitals
Replies: 4
Views: 148

Re: Hybrid Orbitals

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?
by EllenRenskoff-1C
Wed May 23, 2018 8:34 pm
Forum: Bond Lengths & Energies
Topic: Bond Order
Replies: 4
Views: 224

Re: Bond Order

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.
by EllenRenskoff-1C
Tue May 22, 2018 12:11 am
Forum: Lewis Structures
Topic: 3.39 bracket question
Replies: 2
Views: 84

Re: 3.39 bracket question

I believe you would put the brackets around the entire ionic compound because the charge applies to the compound as a whole.
by EllenRenskoff-1C
Fri May 18, 2018 5:18 pm
Forum: Bond Lengths & Energies
Topic: Pentane vs. 2,2 Dimethylpropane
Replies: 3
Views: 247

Pentane vs. 2,2 Dimethylpropane

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...
by EllenRenskoff-1C
Thu May 17, 2018 3:37 pm
Forum: Resonance Structures
Topic: 3.59 part c resonance structure? [ENDORSED]
Replies: 3
Views: 164

Re: 3.59 part c resonance structure? [ENDORSED]

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.
by EllenRenskoff-1C
Tue May 15, 2018 2:00 pm
Forum: Ionic & Covalent Bonds
Topic: Resonance [ENDORSED]
Replies: 5
Views: 209

Re: Resonance [ENDORSED]

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...
by EllenRenskoff-1C
Mon May 14, 2018 6:17 pm
Forum: Ionic & Covalent Bonds
Topic: 3.33
Replies: 5
Views: 145

Re: 3.33

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...
by EllenRenskoff-1C
Fri May 11, 2018 5:10 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge: Lewis dot structures
Replies: 6
Views: 210

Re: Formal Charge: Lewis dot structures

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?
by EllenRenskoff-1C
Tue May 08, 2018 9:54 pm
Forum: Properties of Light
Topic: 4b practice midterm
Replies: 9
Views: 425

Re: 4b practice midterm

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?
by EllenRenskoff-1C
Mon May 07, 2018 12:56 pm
Forum: Significant Figures
Topic: diference in sig figs
Replies: 5
Views: 198

Re: diference in sig figs

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?
by EllenRenskoff-1C
Sat May 05, 2018 4:43 pm
Forum: Significant Figures
Topic: Sig Figs in Heisenberg Uncertainty Principle
Replies: 3
Views: 289

Sig Figs in Heisenberg Uncertainty Principle

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...
by EllenRenskoff-1C
Fri May 04, 2018 7:26 pm
Forum: Balancing Chemical Reactions
Topic: balancing chemical reactions
Replies: 6
Views: 311

Re: balancing chemical reactions

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...
by EllenRenskoff-1C
Wed May 02, 2018 7:57 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: test 2 #4
Replies: 4
Views: 173

Re: test 2 #4

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.
by EllenRenskoff-1C
Tue May 01, 2018 1:58 pm
Forum: Significant Figures
Topic: Use of sigfigs
Replies: 8
Views: 330

Re: Use of sigfigs

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.
by EllenRenskoff-1C
Mon Apr 30, 2018 8:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: cation or anion?
Replies: 4
Views: 168

Re: cation or anion?

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...
by EllenRenskoff-1C
Mon Apr 30, 2018 8:15 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: What does electron spin actually mean? [ENDORSED]
Replies: 9
Views: 309

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

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...
by EllenRenskoff-1C
Thu Apr 26, 2018 3:54 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodal Planes [ENDORSED]
Replies: 6
Views: 186

Re: Nodal Planes [ENDORSED]

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?
by EllenRenskoff-1C
Sat Apr 21, 2018 5:10 pm
Forum: Properties of Light
Topic: units for frequency and wavelength [ENDORSED]
Replies: 9
Views: 235

Re: units for frequency and wavelength [ENDORSED]

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?
by EllenRenskoff-1C
Sat Apr 21, 2018 4:32 pm
Forum: DeBroglie Equation
Topic: HW 1.33
Replies: 12
Views: 416

Re: HW 1.33

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?
by EllenRenskoff-1C
Fri Apr 20, 2018 7:53 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: h-bar [ENDORSED]
Replies: 7
Views: 243

Re: h-bar [ENDORSED]

If h-bar is h/ 2*pi, where does the h/ 4*pi come from in the Heisenberg Indeterminancy Function come from?
by EllenRenskoff-1C
Sat Apr 14, 2018 10:37 am
Forum: Properties of Light
Topic: avogadro's number
Replies: 5
Views: 182

Re: avogadro's number

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.)
by EllenRenskoff-1C
Fri Apr 13, 2018 9:52 pm
Forum: Photoelectric Effect
Topic: Post module quiz #25
Replies: 6
Views: 144

Re: Post module quiz #25

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.
by EllenRenskoff-1C
Fri Apr 13, 2018 9:45 pm
Forum: Photoelectric Effect
Topic: Equations in Quantum Mechanics [ENDORSED]
Replies: 3
Views: 118

Re: Equations in Quantum Mechanics [ENDORSED]

Would classical mechanics be related to discrete variables? I remember that Dr. Lavelle was talking about the distinction between classical and quantum mechanics.
by EllenRenskoff-1C
Thu Apr 12, 2018 10:48 am
Forum: Properties of Light
Topic: HW 1.5 [ENDORSED]
Replies: 7
Views: 251

Re: HW 1.5 [ENDORSED]

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...
by EllenRenskoff-1C
Wed Apr 11, 2018 7:59 pm
Forum: Properties of Light
Topic: HW 1.3 [ENDORSED]
Replies: 12
Views: 435

Re: HW 1.3 [ENDORSED]

Could you explain why option a is incorrect? I was confused about options a and c.
by EllenRenskoff-1C
Tue Apr 10, 2018 9:49 pm
Forum: Properties of Light
Topic: Need help on 1.4
Replies: 2
Views: 123

Re: Need help on 1.4

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!

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