Search found 31 matches
- Wed Jun 06, 2018 5:28 pm
- Forum: Bronsted Acids & Bases
- Topic: H3O vs H2O
- Replies: 5
- Views: 2619
H3O vs H2O
I'm confused on why some equations we've been seeing in class result in H3O+ being formed and others have H2O being formed. Is it because when an acid or base reacts with water it forms H3O+? And when an acid and vase react they produce H2O? Or am I totally off?
- Mon Jun 04, 2018 5:20 pm
- Forum: Lewis Acids & Bases
- Topic: acids/bases electrons
- Replies: 2
- Views: 305
acids/bases electrons
Are molecules only considered acids or bases if they are donating or receiving BOTH electrons?
- Mon Jun 04, 2018 5:19 pm
- Forum: Lewis Acids & Bases
- Topic: weak acids
- Replies: 3
- Views: 405
weak acids
Can someone name some of the weak acids the professor listed in class? Also,how can we tell if they are weak? does it have to do with the varge of the molecules?
- Sun Jun 03, 2018 12:49 pm
- Forum: Biological Examples
- Topic: chemotherapy example [ENDORSED]
- Replies: 4
- Views: 588
chemotherapy example [ENDORSED]
I'm just having a hard time understanding how the DNA bonds with the molecule. What two parts are actually bonding?
- Wed May 30, 2018 8:43 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: homework 4.29
- Replies: 1
- Views: 313
homework 4.29
in this problem there are 3 isomers of C6H4Cl2, and it asks which has the largest dipole moment. it says that the isomer with a smaller bond angle has the largest dipole moment, why is this? I thought it would be opposite.
- Mon May 28, 2018 7:20 pm
- Forum: Hybridization
- Topic: hybridization example
- Replies: 3
- Views: 411
hybridization example
in lecture, we briefly went over hybridization. the professor used carbon as an example. I was wondering why he only drew 4 electrons instead of 6? is it because we only use the valence electrons?
- Wed May 23, 2018 4:50 pm
- Forum: Ionic & Covalent Bonds
- Topic: negative charges and lewis structures
- Replies: 3
- Views: 443
Re: negative charges and lewis structures
Solene Poulhazan wrote:This represents the overall charge of the molecule.
wow I feel dumb, thank you!
- Wed May 23, 2018 3:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: shape of water
- Replies: 8
- Views: 1155
shape of water
is water still considered trigonal pyramidal even though it has 2 lone pairs?
- Wed May 23, 2018 3:19 pm
- Forum: Ionic & Covalent Bonds
- Topic: negative charges and lewis structures
- Replies: 3
- Views: 443
negative charges and lewis structures
hi, I feel like this is a dumb question but I'm genuinely confused. Why does the professor put brackets around lewis structures and then put the charge outside of it? do we have to do this too?
- Sun May 20, 2018 6:03 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Absent Friday
- Replies: 4
- Views: 731
Re: Absent Friday
thank you everyone!
- Fri May 18, 2018 6:20 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Absent Friday
- Replies: 4
- Views: 731
Absent Friday
Hi. I also had to miss class Friday and I was wondering if you guys can tell me what we went over so I know what to read in the book? Or does anyone know if he has lecture topics somewhere on his website? thank you.
- Fri May 18, 2018 6:18 pm
- Forum: Bond Lengths & Energies
- Topic: calculating bond length
- Replies: 3
- Views: 513
calculating bond length
Hi. I was gone Wednesday and I was able to review someone's notes but I'm confused on how we calculate bond length. I saw that we need the dissociation energy, but are we always given bond lengths? how do we calculate it?
- Fri May 18, 2018 6:13 pm
- Forum: Dipole Moments
- Topic: polarization power
- Replies: 3
- Views: 436
polarization power
is polarization power referring to the anions or the cations? I was thinking the anions because they are the ones that want to gain electrons but I feel like I'm wrong. can someone explain?
- Fri May 18, 2018 2:40 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizabilty
- Replies: 1
- Views: 233
Polarizabilty
I had to miss lecture Wednesday and I was wondering if someone can describe what it means To be “highly polarizable”. Thank you.
- Sat May 12, 2018 4:12 pm
- Forum: Ionic & Covalent Bonds
- Topic: radicals [ENDORSED]
- Replies: 9
- Views: 1120
radicals [ENDORSED]
can someone elaborate on radicals? The TA went over them really quickly and I don't remember how she defined them.
- Sat May 05, 2018 7:53 pm
- Forum: Trends in The Periodic Table
- Topic: 2.67 part c) and d) [ENDORSED]
- Replies: 5
- Views: 657
Re: 2.67 part c) and d) [ENDORSED]
I believe your reasoning is right. That's the same explanation I would give; due to the smaller atomic radius, it takes more energy.
- Wed May 02, 2018 9:20 pm
- Forum: Trends in The Periodic Table
- Topic: homework 2.59
- Replies: 3
- Views: 345
Re: homework 2.59
Atomic radii decrease across a period and since P3- appears first it has the greatest atomic radii and S2- and Cl- appear after it respectively on the periodic table meaning that their atomic radii are less than it. Therefore, since it asks for increasing atomic order it would be Cl- < S2- < P3- I ...
- Wed May 02, 2018 8:51 pm
- Forum: Trends in The Periodic Table
- Topic: lecture question 5/2
- Replies: 3
- Views: 342
Re: lecture question 5/2
Hi! I'm not too sure if it was called shell attraction, but how I understood it is that across a period, the atomic radius decreases. This is because across a period, we still remain in the same shell (n=1 for example, or n=2, etc.), yet the number of protons increases. Thus, the electrons are more...
- Wed May 02, 2018 8:47 pm
- Forum: Trends in The Periodic Table
- Topic: homework 2.59
- Replies: 3
- Views: 345
homework 2.59
I am confused on the answer to 2.59. the question says to rank the ions from smallest to largest ionic radius. S2-, Cl-, and P3- I thought the answer would be the all have the same ionization energy because they all end up on Ar on the periodic table after adding electrons. but the solution is P3-,S...
- Wed May 02, 2018 2:11 pm
- Forum: Trends in The Periodic Table
- Topic: lecture question 5/2
- Replies: 3
- Views: 342
lecture question 5/2
can someone explain the concept the professor went over. he talked about why radii get smaller and I know it has to do with attraction to the nucleus. I think it was called shell contraction? (Sorry this is so vague)
- Sun Apr 29, 2018 12:19 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: understanding orbitals [ENDORSED]
- Replies: 8
- Views: 827
understanding orbitals [ENDORSED]
In lecture Wednesday the Professor talked about the fact that we are using math functions to determine where electrons are, but we don't know the shape of an actual electron. So I'm having a hard time understanding what an orbital is. Is it where the electrons are supposed to be? or a path the elect...
- Wed Apr 25, 2018 9:35 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Homework problem 2.1 (d) [ENDORSED]
- Replies: 2
- Views: 345
Homework problem 2.1 (d) [ENDORSED]
D on this problem asks if radius increases as atom goes from 1s to 2p. I answered no, it decreases because atomic radius decreases from left to right on the periodic table. However the solution manual says radius increases because it is related to n... can someone explain?
- Wed Apr 25, 2018 9:33 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: higher energy/ lower energy
- Replies: 2
- Views: 303
higher energy/ lower energy
Today in lecture the professor said s has lower energy than p, p has lower energy than d, d has lower energy than f (in the same shell). how does this relate to electrons? does higher energy mean more electrons or does it relate to frequency? I don't know what to relate the highe/lower enegry back to.
- Sat Apr 21, 2018 3:22 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Uncertainty Equation significance
- Replies: 4
- Views: 424
Uncertainty Equation significance
Yesterday in lecture we went over the uncertainty principle. But I just don't understand why we use it, what significant information do we get from it?
- Sat Apr 21, 2018 3:19 pm
- Forum: Photoelectric Effect
- Topic: Significance of intensity [ENDORSED]
- Replies: 7
- Views: 742
Significance of intensity [ENDORSED]
So I understand that intensity of light does not affect the Energy, frequency does. So what exactly is the importance of the intensity of light? Is it just the amount of photons? Can someone clarify please.
- Sat Apr 21, 2018 3:09 pm
- Forum: Photoelectric Effect
- Topic: Work function [ENDORSED]
- Replies: 6
- Views: 799
Re: Work function [ENDORSED]
Work function is the amount of energy (joules) needed to emit an electron from a photon. Most of the time the work function is given in the problems BUT it is in eV (electrovolts) and you have to convert it to Joules- there is a conversion number you can google. An example of a work function problem...
- Mon Apr 16, 2018 7:39 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Frequency if energy goes from n=2 to n=4
- Replies: 6
- Views: 560
Re: Frequency if energy goes from n=2 to n=4
I had the same question! But I do remember him saying that the energy of a photon can only be positive. But I don't know how that works out.
- Sat Apr 14, 2018 1:39 pm
- Forum: Photoelectric Effect
- Topic: Photons in a light source [ENDORSED]
- Replies: 4
- Views: 225
Re: Photons in a light source [ENDORSED]
I reviewed my notes and cannot find where that was said. are you sure it said photons? you could be mistaking that for electrons. if so no electrons are ejected if the energy of the photon is not greater than or equal to the work function aka the energy needed to eject an electron. so back to the st...
- Sat Apr 14, 2018 1:18 pm
- Forum: Properties of Light
- Topic: Units for Wavelengths [ENDORSED]
- Replies: 4
- Views: 339
Re: Units for Wavelengths [ENDORSED]
I believe Lavelle and the TA's prefer us to concert m to nm but if it's not specified in the problem for example "give the wavelength in nm" then either m or nm is acceptable.
- Sun Apr 08, 2018 12:20 pm
- Forum: Balancing Chemical Reactions
- Topic: possible test question
- Replies: 1
- Views: 259
possible test question
I was wondering if on a test/midterm will we just be given the names of the formulas and have to figure out the actual chemical formula or will be always be given the chemical formula. for example, will we just be given "sodium hydrogen carbonate" or will we be given NaHCO3?
- Sun Apr 08, 2018 11:57 am
- Forum: Significant Figures
- Topic: Sig Figs for Hydrogen
- Replies: 2
- Views: 698
Sig Figs for Hydrogen
I was wondering what molar mass we are supposed to use for hydrogen. I always use 1.01 but in class I believe the professor used 1.008. So my question is, do we use 1.008 or does the mass we use depend on the other molar masses sig figs? and if I use 1.01 instead of 1.008 will is mess up the rest of...