Search found 34 matches

by Hannah Faris 1C
Sat Dec 08, 2018 8:41 pm
Forum: Polyprotic Acids & Bases
Topic: Polyprotics on Final
Replies: 3
Views: 634

Polyprotics on Final

Hey, how much do we need to know about polyprotics for the final? There are no assigned homework questions for the section so I don't have a good gauge of what we should know.

Thanks!!
by Hannah Faris 1C
Sat Dec 08, 2018 8:37 pm
Forum: Air Pollution & Acid Rain
Topic: Acid Rain Formation
Replies: 6
Views: 841

Acid Rain Formation

Hi, can someone re-explain acid rain formation for me? My notes on this aren't very helpful or clear.

Thanks!!
by Hannah Faris 1C
Sat Dec 08, 2018 8:36 pm
Forum: Biological Examples
Topic: Vitamin B-12
Replies: 2
Views: 463

Vitamin B-12

I found somewhere (I think on the syllabus) that we needed to know about Vitamin B-12 but I can't find too much on it in my notes. Can someone explain it to me?

Thanks so much!
by Hannah Faris 1C
Sun Dec 02, 2018 11:29 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Polydentate
Replies: 2
Views: 320

Polydentate

How would you know if a compound is polydentate by just looking at the formula? Would you have to draw it out?
by Hannah Faris 1C
Sun Dec 02, 2018 11:24 pm
Forum: Naming
Topic: Metal Suffix
Replies: 2
Views: 489

Metal Suffix

Can someone remind me again, when is the suffix -ate added to metals?

Thanks!
by Hannah Faris 1C
Sun Dec 02, 2018 5:33 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted v. Lewis v. Arrhenius
Replies: 4
Views: 684

Bronsted v. Lewis v. Arrhenius

Hi, I'm still having trouble differentiating between the different definitions, and what they mean for the entities defined by acids and bases for each definition. Any explanation or examples you could give would help!

Thanks!
by Hannah Faris 1C
Tue Nov 27, 2018 9:47 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: ion-ion bond vs. H-bond
Replies: 4
Views: 760

Re: ion-ion bond vs. H-bond

An ion-ion bond would be an ionic bond, which is the strongest type of bond. This is because it is based on the transfer of electrons, whereas an H bond is more like an electrostatic attraction between a proton and lone pair. This is also evidenced by the high melting/boiling points of ionic substan...
by Hannah Faris 1C
Mon Nov 26, 2018 2:48 pm
Forum: Sigma & Pi Bonds
Topic: Pi Strength
Replies: 4
Views: 443

Re: Pi Strength

wait friend I think a sigma bond is stronger not weaker bc they overlap more directly. But going by that logic that does answer my question bc then the pi bond would break first (since it's weaker). I didn't even consider the relative strengths so thank you for bringing it up!
by Hannah Faris 1C
Mon Nov 26, 2018 2:28 pm
Forum: Sigma & Pi Bonds
Topic: Pi Strength
Replies: 4
Views: 443

Pi Strength

Hi, Prof. Lavelle stressed the fact that Pi bonds prevent rotation from happening, and if the atoms rotate the bond breaks. Does this mean that a pi bond would normally break before a sigma bond if energy is applied to a molecule?

Thanks!
by Hannah Faris 1C
Mon Nov 26, 2018 2:27 pm
Forum: Hybridization
Topic: Just Kind of Confused
Replies: 13
Views: 1058

Re: Just Kind of Confused

The only reason for moving the d orbital in front is to clarify that it is a lower energy orbital than the s and p orbitals, but I've seen it notated both ways.
by Hannah Faris 1C
Mon Nov 26, 2018 2:25 pm
Forum: General Science Questions
Topic: Redox Reactions
Replies: 1
Views: 246

Redox Reactions

Does anyone know if there will be a chapter that specifically covers redox reactions or will they just be integrated into the course naturally? Just trying to figure out how much I need to brush up on.
by Hannah Faris 1C
Mon Nov 26, 2018 2:21 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Hydrates
Replies: 1
Views: 243

Hydrates

Hi, Prof. Lavelle mentioned a hydrate in class today, how much do we have to know about hydrates? How familiar should we be with them in general?

Thanks!!
by Hannah Faris 1C
Mon Nov 26, 2018 2:18 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Oxidation Numbers
Replies: 1
Views: 518

Oxidation Numbers

Can someone explain how an oxidation number is calculated, and how it differs from a formal charge? In what situation would one be used over the other?

Thanks!
by Hannah Faris 1C
Sun Nov 18, 2018 1:23 pm
Forum: Coordinate Covalent Bonds
Topic: Shape of the Molecule Contributes to Strength of Interaction
Replies: 2
Views: 571

Re: Shape of the Molecule Contributes to Strength of Interaction

Yeah just to add on a little more, molecular formula only gives the ratio of elements in a compound. Without the full name of the compound you really wouldn't know the shape/configuration at all.
by Hannah Faris 1C
Sun Nov 18, 2018 1:16 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: Homework Question: 3F.13
Replies: 1
Views: 302

Homework Question: 3F.13

Hi, I was just confused about question 3F.13. It shows a bunch of molecules and you're supposed to tell which one has the strongest intermolecular attractions and why. How are we supposed to determine this from the picture? I'm not really sure how to approach the problem at all.

Thanks!
by Hannah Faris 1C
Sat Nov 17, 2018 9:13 pm
Forum: Hybridization
Topic: Hybridization
Replies: 2
Views: 300

Hybridization

I read the book section on Hybridization but I'm still a little confused. What is hybridization and how is it determined? Also, for the regions of electron density around an atom, is the hybridization all the same?

Thanks!
by Hannah Faris 1C
Sat Nov 10, 2018 10:16 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Definitions: Molecular v. Electron Pair Geometry [ENDORSED]
Replies: 1
Views: 405

Definitions: Molecular v. Electron Pair Geometry [ENDORSED]

What's the difference between molecular geometry and electron pair geometry?
by Hannah Faris 1C
Sat Nov 10, 2018 10:05 pm
Forum: Dipole Moments
Topic: Dipole Moments [ENDORSED]
Replies: 10
Views: 1012

Dipole Moments [ENDORSED]

Does anyone know if we would ever have to calculate anything like a dipole moment? It might have been said in class but I just can't remember at all.

Thanks so much!
by Hannah Faris 1C
Sat Nov 10, 2018 10:04 pm
Forum: Hybridization
Topic: How to Determine
Replies: 12
Views: 1166

How to Determine

Could someone explain what causes hybridization? I think I'm just a little confused overall.

Thanks!!
by Hannah Faris 1C
Fri Nov 02, 2018 9:27 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Exam 2 Question 2
Replies: 1
Views: 309

Exam 2 Question 2

The question was : the uncertainty in momentum (delta p) of a 0.0240 kg cricket ball, which is traveling at 150. km/hr, is 1*10^-6 times its momentum. Calculate its minimum delta x. I solved everything out but I think my scientific notation was off. I multiplied the given uncertainty by 150 km/hr, m...
by Hannah Faris 1C
Fri Nov 02, 2018 9:16 pm
Forum: Properties of Light
Topic: Exam 2 Question 4A
Replies: 6
Views: 890

Exam 2 Question 4A

The question was : at the threshold voltage, light is emitted with energy equal to 3.61*10^-22kJ, what is the frequency of the photon? I used both of the light equations to convert the energy into the frequency, but I'm not entirely sure what I did wrong. I would be really thankful if I could see so...
by Hannah Faris 1C
Fri Nov 02, 2018 9:10 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Exam 2 Question 1A
Replies: 2
Views: 410

Exam 2 Question 1A

Hi I need some help with the first question on the second exam. The question was :alveoli are tiny sacs in the lungs whose average diameter is 2*10^-4 m; if an oxygen molecule is trapped inside the sac find its uncertainty in velocity. I tried to find the mass of one atom by dividing one atom by avo...
by Hannah Faris 1C
Fri Oct 26, 2018 10:17 pm
Forum: Trends in The Periodic Table
Topic: Ionization Energy and Electron Affinity
Replies: 9
Views: 1886

Ionization Energy and Electron Affinity

Can someone explain the difference between ionization energy and electron affinity?
by Hannah Faris 1C
Fri Oct 26, 2018 10:15 pm
Forum: Sigma & Pi Bonds
Topic: Sigma v. Pi
Replies: 6
Views: 903

Sigma v. Pi

Can someone explain the difference between a sigma and pi bond?

Thanks!!
by Hannah Faris 1C
Fri Oct 26, 2018 10:14 pm
Forum: Resonance Structures
Topic: Resonance Structures
Replies: 5
Views: 460

Resonance Structures

Hi, I just wanted to ask what causes resonance structures, and how to know if a molecule has one? Just wanted to know!!

Thanks!
by Hannah Faris 1C
Fri Oct 19, 2018 1:32 pm
Forum: Trends in The Periodic Table
Topic: atomic orbitals
Replies: 2
Views: 283

Re: atomic orbitals

Yeah just to kind of second and simplify what was already said, atomic orbitals are basically the probability of finding an electron in a certain area (so they aren’t really orbitals the way they’re commonly drawn in books). They’re just kind of a cloud that describes where the electron is most like...
by Hannah Faris 1C
Fri Oct 19, 2018 1:22 pm
Forum: Properties of Light
Topic: Equations
Replies: 7
Views: 558

Equations

Hi, I’m a little bit confused about the use of equations.

Which equations do we use for solving for particles, and which are for light? I need some help getting them straightened out in my head.

Thanks!
by Hannah Faris 1C
Fri Oct 19, 2018 1:19 pm
Forum: *Shrodinger Equation
Topic: Shrodinger Equation on Test
Replies: 5
Views: 414

Shrodinger Equation on Test

Does anyone know really how much about the Shrodinger Equation we need to understand for the test? I get some of it but I just want to figure out how much time I should put into reviewing it.

Thanks!
by Hannah Faris 1C
Thu Oct 11, 2018 10:13 pm
Forum: Properties of Light
Topic: Question 1B.7 7th Edition
Replies: 2
Views: 225

Question 1B.7 7th Edition

Hi, I'm not sure at all how to approach this question. The question is: "Sodium vapor lamps emit yellow light of wavelength 589 nm. How much energy is emitted by a) an excited sodium atom when it generates a photon (b) 5.00 mg of sodium atoms emitting light at this wavelength (c) 1.00 mol of so...
by Hannah Faris 1C
Thu Oct 11, 2018 10:08 pm
Forum: *Shrodinger Equation
Topic: Shrodinger Equation Meaning
Replies: 3
Views: 297

Shrodinger Equation Meaning

Just to clarify, does the Shrodinger equation give the energy solutions for just one particle or all of them? Or am I wrong entirely about what the solution of the equation means?
by Hannah Faris 1C
Thu Oct 11, 2018 10:04 pm
Forum: Properties of Light
Topic: Explaining answer for 1.3
Replies: 4
Views: 398

Re: Explaining answer for 1.3

To my knowledge, the change of the electric fields corresponds to the frequency directly, so it makes sense that they would go down together (because the wave itself is the electrical field, since it oscillates less frequently there is less overall change). I'm not entirely sure though!
by Hannah Faris 1C
Wed Oct 03, 2018 12:06 pm
Forum: Significant Figures
Topic: Accepted range of answers
Replies: 2
Views: 261

Re: Accepted range of answers

Professor also said that as long as it doesn't contribute to over 5% error you should be fine, though I'm not sure how easily you'd be able to calculate that efficiently when it matters. But just as info!
by Hannah Faris 1C
Wed Oct 03, 2018 12:00 pm
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Mole Definition
Replies: 5
Views: 744

Re: Mole Definition

From what I heard in a different chemistry course that I've taken, it was chosen on purpose (like as a base? Because carbon-12 is the most common isotope of carbon, the base of life). This is related to the definition of an amu, where 1 amu = 1/12 the mass of a carbon-12 atom. 1 amu=1g/mol which mea...
by Hannah Faris 1C
Wed Oct 03, 2018 11:44 am
Forum: Accuracy, Precision, Mole, Other Definitions
Topic: Question E 15
Replies: 2
Views: 168

Re: Question E 15

Yeah, that's all correct. As you have done, you subtract 2 times the molar mass of OH from the given molar mass, and then add the molar mass of sulfur to find the total molar mass it as a sulfide. Since the oxidation numbers check out (unknown metal is +2, sulfur is -2) you only need to use one sulf...

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