Search found 31 matches

by tatianatumbling_1J
Wed Jun 06, 2018 5:28 pm
Forum: Bronsted Acids & Bases
Topic: H3O vs H2O
Replies: 5
Views: 316

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?
by tatianatumbling_1J
Mon Jun 04, 2018 5:20 pm
Forum: Lewis Acids & Bases
Topic: acids/bases electrons
Replies: 2
Views: 89

acids/bases electrons

Are molecules only considered acids or bases if they are donating or receiving BOTH electrons?
by tatianatumbling_1J
Mon Jun 04, 2018 5:19 pm
Forum: Lewis Acids & Bases
Topic: weak acids
Replies: 3
Views: 112

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?
by tatianatumbling_1J
Sun Jun 03, 2018 12:49 pm
Forum: Biological Examples
Topic: chemotherapy example [ENDORSED]
Replies: 4
Views: 270

chemotherapy example [ENDORSED]

I'm just having a hard time understanding how the DNA bonds with the molecule. What two parts are actually bonding?
by tatianatumbling_1J
Wed May 30, 2018 8:43 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: homework 4.29
Replies: 1
Views: 73

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.
by tatianatumbling_1J
Mon May 28, 2018 7:20 pm
Forum: Hybridization
Topic: hybridization example
Replies: 3
Views: 117

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?
by tatianatumbling_1J
Wed May 23, 2018 4:50 pm
Forum: Ionic & Covalent Bonds
Topic: negative charges and lewis structures
Replies: 3
Views: 121

Re: negative charges and lewis structures

Solene Poulhazan wrote:This represents the overall charge of the molecule.

wow I feel dumb, thank you!
by tatianatumbling_1J
Wed May 23, 2018 3:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: shape of water
Replies: 8
Views: 209

shape of water

is water still considered trigonal pyramidal even though it has 2 lone pairs?
by tatianatumbling_1J
Wed May 23, 2018 3:19 pm
Forum: Ionic & Covalent Bonds
Topic: negative charges and lewis structures
Replies: 3
Views: 121

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?
by tatianatumbling_1J
Sun May 20, 2018 6:03 pm
Forum: Administrative Questions and Class Announcements
Topic: Absent Friday
Replies: 4
Views: 333

Re: Absent Friday

thank you everyone!
by tatianatumbling_1J
Fri May 18, 2018 6:20 pm
Forum: Administrative Questions and Class Announcements
Topic: Absent Friday
Replies: 4
Views: 333

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.
by tatianatumbling_1J
Fri May 18, 2018 6:18 pm
Forum: Bond Lengths & Energies
Topic: calculating bond length
Replies: 3
Views: 145

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?
by tatianatumbling_1J
Fri May 18, 2018 6:13 pm
Forum: Dipole Moments
Topic: polarization power
Replies: 3
Views: 152

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?
by tatianatumbling_1J
Fri May 18, 2018 2:40 pm
Forum: Polarisability of Anions, The Polarizing Power of Cations
Topic: Polarizabilty
Replies: 1
Views: 82

Polarizabilty

I had to miss lecture Wednesday and I was wondering if someone can describe what it means To be “highly polarizable”. Thank you.
by tatianatumbling_1J
Sat May 12, 2018 4:12 pm
Forum: Ionic & Covalent Bonds
Topic: radicals [ENDORSED]
Replies: 9
Views: 280

radicals [ENDORSED]

can someone elaborate on radicals? The TA went over them really quickly and I don't remember how she defined them.
by tatianatumbling_1J
Sat May 05, 2018 7:53 pm
Forum: Trends in The Periodic Table
Topic: 2.67 part c) and d) [ENDORSED]
Replies: 5
Views: 223

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.
by tatianatumbling_1J
Wed May 02, 2018 9:20 pm
Forum: Trends in The Periodic Table
Topic: homework 2.59
Replies: 3
Views: 80

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 ...
by tatianatumbling_1J
Wed May 02, 2018 8:51 pm
Forum: Trends in The Periodic Table
Topic: lecture question 5/2
Replies: 3
Views: 103

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...
by tatianatumbling_1J
Wed May 02, 2018 8:47 pm
Forum: Trends in The Periodic Table
Topic: homework 2.59
Replies: 3
Views: 80

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...
by tatianatumbling_1J
Wed May 02, 2018 2:11 pm
Forum: Trends in The Periodic Table
Topic: lecture question 5/2
Replies: 3
Views: 103

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)
by tatianatumbling_1J
Sun Apr 29, 2018 12:19 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: understanding orbitals [ENDORSED]
Replies: 8
Views: 229

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...
by tatianatumbling_1J
Wed Apr 25, 2018 9:35 pm
Forum: Quantum Numbers and The H-Atom
Topic: Homework problem 2.1 (d) [ENDORSED]
Replies: 2
Views: 99

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?
by tatianatumbling_1J
Wed Apr 25, 2018 9:33 pm
Forum: Quantum Numbers and The H-Atom
Topic: higher energy/ lower energy
Replies: 2
Views: 117

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.
by tatianatumbling_1J
Sat Apr 21, 2018 3:22 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Uncertainty Equation significance
Replies: 4
Views: 120

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?
by tatianatumbling_1J
Sat Apr 21, 2018 3:19 pm
Forum: Photoelectric Effect
Topic: Significance of intensity [ENDORSED]
Replies: 7
Views: 214

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.
by tatianatumbling_1J
Sat Apr 21, 2018 3:09 pm
Forum: Photoelectric Effect
Topic: Work function [ENDORSED]
Replies: 6
Views: 345

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...
by tatianatumbling_1J
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: 215

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.
by tatianatumbling_1J
Sat Apr 14, 2018 1:39 pm
Forum: Photoelectric Effect
Topic: Photons in a light source [ENDORSED]
Replies: 4
Views: 86

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...
by tatianatumbling_1J
Sat Apr 14, 2018 1:18 pm
Forum: Properties of Light
Topic: Units for Wavelengths [ENDORSED]
Replies: 4
Views: 119

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.
by tatianatumbling_1J
Sun Apr 08, 2018 12:20 pm
Forum: Balancing Chemical Reactions
Topic: possible test question
Replies: 1
Views: 117

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?
by tatianatumbling_1J
Sun Apr 08, 2018 11:57 am
Forum: Significant Figures
Topic: Sig Figs for Hydrogen
Replies: 2
Views: 107

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...

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