Search found 101 matches
- Sat Mar 14, 2020 2:20 pm
- Forum: Student Social/Study Group
- Topic: Review Sessions
- Replies: 4
- Views: 434
Re: Review Sessions
Dr. Lavelle also posted review questions on his website under "Week 10 Review" that are helpful.
- Sat Mar 14, 2020 2:18 pm
- Forum: Student Social/Study Group
- Topic: Coronavirus Joke
- Replies: 14
- Views: 1817
Re: Coronavirus Joke
Solid.
- Sat Mar 14, 2020 2:17 pm
- Forum: Student Social/Study Group
- Topic: Week 10 Review Question
- Replies: 5
- Views: 481
Re: Week 10 Review Question
By knowing the change in one of the reactants/products over the reaction, we can use the stoichiometric ratio to calculate the change for the others.
- Sat Mar 14, 2020 2:16 pm
- Forum: Student Social/Study Group
- Topic: Curve?
- Replies: 50
- Views: 6403
Re: Curve?
I think that way it works out is that each individual test isn't curved, but once the class average is known at the end of the quarter, the grades are curved to reflect that average. But, included in that curve/scaling is that if someone gets at least 250 points out of the 500, they are guaranteed a...
- Sat Mar 14, 2020 2:14 pm
- Forum: Student Social/Study Group
- Topic: Online textbook answer key
- Replies: 6
- Views: 610
Re: Online textbook answer key
Yeah, I've had this problem in the past, too. Unfortunately I can't offer a solution, mine just usually loads when I give it enough time. Any solutions would be helpful.
- Sun Mar 08, 2020 10:38 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing a reaction
- Replies: 5
- Views: 400
Re: Balancing a reaction
To balance the overall reaction, you have to separate into the redox half reactions, and use H+/OH- and H2O to balance those. After doing that, you just add the two reactions together and get the overall balanced reaction.
- Sun Mar 08, 2020 10:35 pm
- Forum: Balancing Redox Reactions
- Topic: Balancing basic reactions
- Replies: 8
- Views: 566
Re: Balancing basic reactions
For a basic reaction, just analyze it and use OH- and H2O on either side and make sure that in the end, it is balanced.
- Sun Mar 08, 2020 10:33 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: galvanic vs electrolytic
- Replies: 12
- Views: 904
Re: galvanic vs electrolytic
Galvanic cells use spontaneous reactions. Electrolytic cells are non-spontaneous, meaning that energy is needed to force the reaction to happen.
- Sun Mar 08, 2020 10:32 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 6
- Views: 437
Re: Cell Diagrams
If the two molecules are in the same phase, you use a comma. But, if the molecules are in different phases, then it's a vertical line, the same as between the different reacting molecules.
- Sun Mar 08, 2020 10:30 pm
- Forum: Student Social/Study Group
- Topic: Final Jitters
- Replies: 457
- Views: 366258
Re: Final Jitters
The biggest thing I try to think that helps to stay calm during tests like the final is just to convince myself right before the test that if I come across a problem that I don't immediately know how to solve, that I am smart enough to solve any problem that could be on the test. We are all smart en...
- Sun Mar 08, 2020 10:26 pm
- Forum: Student Social/Study Group
- Topic: Test 2 Homework Problems, Etc
- Replies: 6
- Views: 443
Re: Test 2 Homework Problems, Etc
In my opinion, the textbook does a better job explaining what we need to do for the hw problems. I like learning from lecture better, but because the hw problems are in the textbook, they're obviously gonna be based off of the wording and specific equations that are in the textbook readings.
- Sun Mar 01, 2020 8:07 pm
- Forum: Balancing Redox Reactions
- Topic: Acidic and Basic solutions
- Replies: 11
- Views: 753
Re: Acidic and Basic solutions
You use h2o and it's ions to balance the equations, but in acid you use H+, and in bases you use oh-
- Sun Mar 01, 2020 8:06 pm
- Forum: Balancing Redox Reactions
- Topic: 6L.9
- Replies: 3
- Views: 267
Re: 6L.9
Yeah I think you're right that we have to take the most stable one / the one that we see most often and use it in this case.
- Sun Mar 01, 2020 8:03 pm
- Forum: Balancing Redox Reactions
- Topic: OH and H
- Replies: 8
- Views: 497
Re: OH and H
They can be on either side cuz you just add them to make sure that everything is balanced
- Sun Mar 01, 2020 8:03 pm
- Forum: Balancing Redox Reactions
- Topic: basic solution
- Replies: 4
- Views: 329
Re: basic solution
Since essentially acid and base reactions are opposite, it would be the other part of the h2o molecule, which is the oh- instead of the h+ in acid solutions.
- Sun Mar 01, 2020 8:01 pm
- Forum: Balancing Redox Reactions
- Topic: homework topic 6K
- Replies: 4
- Views: 378
Re: homework topic 6K
to make sure that the atoms are balanced on each side.
- Sun Feb 23, 2020 3:41 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy Equation that relates K
- Replies: 4
- Views: 350
Re: Gibbs Free Energy Equation that relates K
This equation takes into account the deltaG(naught) and adds/subtracts what would be different because of the conditions not being standard.
- Sun Feb 23, 2020 3:40 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Derivations
- Replies: 5
- Views: 315
Re: Derivations
I think that the derivations are pretty much all listed on the equation sheet, so we'd only need to be able to know how to use them.
- Sun Feb 23, 2020 3:39 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Spontaneous
- Replies: 23
- Views: 1247
Re: Spontaneous
If deltaG is equal to 0, than the reaction is at equilibrium, and not proceeding in either direction.
- Sun Feb 23, 2020 3:35 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Enthalpy
- Replies: 26
- Views: 1223
Re: Enthalpy
Something being a state function means that the pathway by which the value arrived at its final value does not matter in the calculation of the value.
- Sun Feb 23, 2020 3:31 pm
- Forum: Balancing Redox Reactions
- Topic: Half Reactions
- Replies: 12
- Views: 856
Re: Half Reactions
A "half reaction" is when you split up the redox reaction into the oxidation reaction and the reduction reaction. So, instead of the electrons being transferred from one atom/molecule to another, we can see just the way the electrons are changed in a single one of the reaction molecules.
- Sun Feb 16, 2020 9:08 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibb's Free Energy
- Replies: 7
- Views: 382
Re: Gibb's Free Energy
Gibbs Free Energy is the most accurate way of measuring whether a reaction will be spontaneous. If it's negative, the reaction is spontaneous. If it's positive, the reaction isn't spontaneous.
- Sun Feb 16, 2020 9:07 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Equilibrium [ENDORSED]
- Replies: 3
- Views: 292
Re: Equilibrium [ENDORSED]
At equilibrium, the energy coming in and being released by work are equal. Basically, the net work being done on and by the system is 0 because the energy of the system is at eq.
- Sun Feb 16, 2020 9:05 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: How to interpret reversible/irreversible graphs
- Replies: 6
- Views: 699
Re: How to interpret reversible/irreversible graphs
The temperature is considered "constant" for reversible actions, but not because it doesn't change at all. It's constant because the change is so slow that at an instantaneous moment, it is not really changing. Plus, the system temp and the surrounding temp stay the same as each other.
- Sun Feb 16, 2020 9:02 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Pizza Rolls REVIEW Session DOWNLOAD HERE
- Replies: 67
- Views: 5779
Re: Pizza Rolls REVIEW Session DOWNLOAD HERE
Thanks to everyone that helped out with questions that people were asking here. It was a big help for reviewing for the midterm.
- Wed Feb 12, 2020 1:47 am
- Forum: Administrative Questions and Class Announcements
- Topic: Pizza Rolls REVIEW Session DOWNLOAD HERE
- Replies: 67
- Views: 5779
Re: Pizza Rolls REVIEW Session DOWNLOAD HERE
Can someone pls explain how to find heat and work in question #6? I get that deltaU and deltaS are 0 because they are state functions, but how/what equations do I use to find work and heat?
- Sun Feb 09, 2020 9:17 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Isolated// Energy
- Replies: 11
- Views: 604
Re: Isolated// Energy
Energy of a isolated system is always conserved (1st law), so even in an isolated system as big as the entire universe, the overall change in energy is 0
- Sun Feb 09, 2020 9:15 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Gas Expansion
- Replies: 3
- Views: 193
Re: Gas Expansion
Gas always spontaneously expands when put into a larger container, and never contracts into a space smaller than all available.
- Sun Feb 09, 2020 9:12 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Evaluating the Stability of a Process
- Replies: 2
- Views: 168
Re: Evaluating the Stability of a Process
I think that what would decide this is whether separating the HCN molecule into its different elements will occur spontaneously, which is based on whether the reaction is exothermic or endothermic. Because breaking bonds requires energy, I don't think this reaction would occur by itself.
- Sun Feb 09, 2020 9:04 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: First Law of Thermodynamics Definition
- Replies: 4
- Views: 246
Re: First Law of Thermodynamics Definition
If you define a system, and it loses energy to its surroundings, which you don't count as part of the system, then the energy WITHIN the system isn't conserved, but the overall energy of the system+surroundings is still constant.
- Sun Feb 09, 2020 9:02 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Spontaneous vs Favorable
- Replies: 8
- Views: 467
Re: Spontaneous vs Favorable
They both mean that the reaction will occur without energy coming from external sources being necessary. I think, as the people said above, there's been a shift toward using the word favorable, because spontaneous comes with the connotation that it will happen quickly, when in reality it just means ...
- Sun Feb 02, 2020 3:11 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Constant Pressure vs Constant Volume
- Replies: 4
- Views: 352
Re: Constant Pressure vs Constant Volume
You can also get the amount of work thru the graphs, because the area under the pressure-volume graph is equal to the work. So, when volume is constant, the graph is a vertical line, and there is no area underneath and therefore no work done. When pressure is constant, the area underneath is a squar...
- Sun Feb 02, 2020 3:07 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Closed system
- Replies: 5
- Views: 232
Re: Closed system
Basically what they said above, the volume of a closed system can change when its container expands or contracts, but the amount of mass will not change.
- Sun Feb 02, 2020 3:05 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Systems
- Replies: 4
- Views: 202
Re: Systems
An open system can gain/lose energy from the environment. A closed system will not lose energy between the internal parts of the system, but its surroundings can add/take energy from the entire system. An isolated system does not gain or lose energy from the surroundings.
- Sun Feb 02, 2020 3:03 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Closed Systems
- Replies: 14
- Views: 941
Re: Closed Systems
On a closed system, you can add energy by adding it to the entire system, which is different from an open system where you can pick where to add work/energy, or an isolated system where you can't add energy, I think.
- Sun Feb 02, 2020 3:02 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Study Advice
- Replies: 73
- Views: 7115
Re: Study Advice
I'd probably say the drop-in sections are better if you have specific questions about the material, but if it's more than you want a review of an entire topic, the 2-hour workshops have been good in my opinion.
- Sun Jan 26, 2020 9:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE
- Replies: 20
- Views: 932
Re: ICE
Use ICE when you are given K and need to find the equilibrium concentrations of the molecules.
- Sun Jan 26, 2020 9:31 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: protonization/ionization
- Replies: 4
- Views: 171
Re: protonization/ionization
It's the non-h30/oh molecule of the product divided by the non-water molecule of the reactants.
- Sun Jan 26, 2020 9:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5% Rule
- Replies: 9
- Views: 355
Re: 5% Rule
Yeah, it being less than 5% just means u can neglect it the x that is subtracted when calculating the Kc using x
- Sun Jan 26, 2020 9:28 pm
- Forum: Ideal Gases
- Topic: PV=NRT
- Replies: 3
- Views: 207
Re: PV=NRT
Would we use this if given a volume of gas and not the number of moles?
- Sun Jan 26, 2020 9:27 pm
- Forum: Ideal Gases
- Topic: Determining N
- Replies: 9
- Views: 426
Re: Determining N
You can only use pvnrt for gases, so in the calculations, use the moles of gas.
- Sun Jan 19, 2020 5:57 pm
- Forum: Ideal Gases
- Topic: inert gas
- Replies: 5
- Views: 267
Re: inert gas
Inert gases, usually just the noble gases including helium, don't react with other substances. Because of that, we can add it to a solution and the volume will increase without altering the reaction.
- Sun Jan 19, 2020 5:55 pm
- Forum: Ideal Gases
- Topic: R constant in Ideal Gas Law
- Replies: 4
- Views: 140
Re: R constant in Ideal Gas Law
R= 8.314 J/mol*K if the units we're using is atms, which is usually is.
- Sun Jan 19, 2020 5:53 pm
- Forum: Ideal Gases
- Topic: PV=nRT
- Replies: 13
- Views: 700
Re: PV=nRT
I think the most important way we can use this formula in this class is to convert between partial pressure and concentration when we need to. Other than that it is used more for physics than chemistry.
- Sun Jan 19, 2020 5:52 pm
- Forum: Ideal Gases
- Topic: concentration
- Replies: 5
- Views: 185
Re: concentration
P is partial pressure, n/V is concentration because it's the number of moles divided by the volume of the solution, so using PV=nRT, you can convert between the two.
- Sun Jan 19, 2020 5:50 pm
- Forum: Ideal Gases
- Topic: response to change in equilibria
- Replies: 6
- Views: 393
Re: response to change in equilibria
There's a longer explanation that I'm sure is in the textbook, but like was said above, when pressure increases, the reaction will shift to the side with less moles.
- Sun Jan 12, 2020 8:20 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Kp and Kc
- Replies: 4
- Views: 263
Re: Kp and Kc
You can use PV=nRT to convert between partial pressure and concentration for a gas so that you make sure all the units are the same.
- Sun Jan 12, 2020 8:18 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K and Q
- Replies: 10
- Views: 314
Re: K and Q
K is the equilibrium constant. Q is the same calculation as K, but when the reaction isn't at equilibrium. From the value of Q, you can tell if the reaction is making more products or reactants.
- Sun Jan 12, 2020 8:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Studying tips
- Replies: 10
- Views: 499
Re: Studying tips
Also make sure you look at the syllabus and which chapters of the textbook are in each topic that we've learned about so you can make sure you're studying the right things.
- Sun Jan 12, 2020 8:16 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Inert Gases
- Replies: 4
- Views: 179
Re: Inert Gases
The main inert gases are the ones in the far-right column of the periodic table because they have full octets. (He too because it only takes 2 electrons and has both)
- Sun Jan 12, 2020 8:14 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Hw for next week
- Replies: 19
- Views: 808
Re: Hw for next week
I think you should prob be find doing some of them as equilibrium but should do some as the next topic too. Last quarter in 14a my TA gave credit as long as the 5 problems were about pretty recent topics, and being that it'll be week 2, I feel like it would be ok.
- Sat Dec 07, 2019 9:22 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: negative pH
- Replies: 4
- Views: 355
Re: negative pH
I doubt Lavelle will give us a problem where the pH is negative, but if that's what the calculation comes out to, than yeah it means that the molarity of hydrogen ions >1
- Sat Dec 07, 2019 9:20 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Equilibrium calculations
- Replies: 6
- Views: 413
Re: Equilibrium calculations
Calculate in the Ka and Kb aren't hard though if he gives us the concentrations of the reactants and products. Other than that, I dont think we'll have to calculate it because its in 14b
- Sat Dec 07, 2019 9:19 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Ka. Kb, Kw
- Replies: 4
- Views: 1390
Re: Ka. Kb, Kw
For strong acids, you just calculate pH, not Ka or Kb.
Ka is equal to the concentration of the products divided by the concentration of the reactants, so unless you are given those, you won't have to calculate it. Then, finding pKa is the negative log of it. pKa + pKb = 14
Ka is equal to the concentration of the products divided by the concentration of the reactants, so unless you are given those, you won't have to calculate it. Then, finding pKa is the negative log of it. pKa + pKb = 14
- Sun Dec 01, 2019 2:21 pm
- Forum: Lewis Acids & Bases
- Topic: Lewis Acids
- Replies: 3
- Views: 253
Re: Lewis Acids
An acid accepts an electron pair, a base donates an electron pair.
- Sun Dec 01, 2019 2:17 pm
- Forum: Amphoteric Compounds
- Topic: Amphoteric Compounds - do we need to memorize them?
- Replies: 2
- Views: 218
Re: Amphoteric Compounds - do we need to memorize them?
There are only a few amphoteric compounds, so it probably wouldn't be hard to memorize them just in case, or at least be familiar with them
- Sun Dec 01, 2019 2:14 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Strong vs Weak Acids and Bases
- Replies: 5
- Views: 421
Re: Strong vs Weak Acids and Bases
Pretty much, the more ionic character a molecule has (EN difference, bond length), the stronger acid it is
- Sun Dec 01, 2019 2:12 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: pKb and pKa
- Replies: 2
- Views: 192
Re: pKb and pKa
The only way to calculate the Ka or Kb would be if you are given the concentrations of both ions and the molecule in the water. The equation is that Ka=[products]/[reactants], or the multiplied concentrations of the ions divided by the concentration of the full molecule. That gives you the amount th...
- Sun Dec 01, 2019 2:10 pm
- Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
- Topic: Ionization of weak/strong acids and bases in water
- Replies: 2
- Views: 183
Re: Ionization of weak/strong acids and bases in water
Also, if they give you the Ka, then you know it's a weak acid/base because strong acids/bases ionize completely
- Sun Nov 24, 2019 8:18 pm
- Forum: Lewis Structures
- Topic: Octet Rule
- Replies: 7
- Views: 658
Re: Octet Rule
It don't think they would keep going after the formal charge reaches 0 because then the molecule is becoming less stable than it was when the FC was 0, and molecules try to stay as stable as possible.
- Sun Nov 24, 2019 8:16 pm
- Forum: Lewis Structures
- Topic: Bent or Angular?
- Replies: 18
- Views: 1168
Re: Bent or Angular?
I don't think it matters cuz its clear what you mean by both.
- Sun Nov 24, 2019 8:15 pm
- Forum: Lewis Structures
- Topic: Strength of bonds
- Replies: 3
- Views: 431
Re: Strength of bonds
There is also a bigger electronegativity difference in the HO bond, which means it is has more ionic character and is therefore stronger.
- Sun Nov 24, 2019 8:14 pm
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures
- Replies: 7
- Views: 587
Re: Drawing Lewis Structures
I think that we might have to test the formal charges of the differently drawn lewis structures to find our wether its a chain or a ring, but hopefully we won't be given one of those, or there will be parts in parenthesis so that we can tell.
- Sun Nov 24, 2019 8:12 pm
- Forum: Lewis Structures
- Topic: Cis- vs Trans- bonds
- Replies: 5
- Views: 474
Re: Cis- vs Trans- bonds
It wasn't on that test but I'd guess we might have to know it for the final.
- Sun Nov 17, 2019 7:49 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Length
- Replies: 22
- Views: 1284
Re: Bond Length
We don't determine bond lengths ourselves, we are given the lengths because they have been experimentally found from repeated experiments of different molecules involving the same atom.
- Sun Nov 17, 2019 7:47 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Rod vs spherical shaped molecules
- Replies: 10
- Views: 1713
Re: Rod vs spherical shaped molecules
Rod shaped molecules interact more easily because of the increased surface area, and also because when they line up next to each other, their nucleus's and electrons can get closer together because in the short side of the rod, the outside of the molecule is closer to the nucleus's.
- Sun Nov 17, 2019 7:44 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: Is there a point where induced dipole induced dipole is stronger than ion ion?
- Replies: 2
- Views: 194
Re: Is there a point where induced dipole induced dipole is stronger than ion ion?
The bonds in ions are always ionically stronger than the induced dipole bond, because it all depends on the electronegativity difference in between the atoms. When they reach a certain point, it's considered an induced dipole, and at an increased point in EN difference, it is called an ion.
- Sun Nov 17, 2019 7:42 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: Intermolecular Forces in Molecules or Between Molecules
- Replies: 3
- Views: 306
Re: Intermolecular Forces in Molecules or Between Molecules
When we talk about the intermolecular forces, it's just between the different molecules, in between atoms of the same molecule is different and has different affects on the structure of molecules and substances.
- Sun Nov 17, 2019 7:41 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: dipole moments
- Replies: 7
- Views: 435
Re: dipole moments
Yeah, when two atoms that have an electronegativity difference, a dipole moment occurs between those two atoms.
- Sun Nov 10, 2019 4:57 pm
- Forum: Ionic & Covalent Bonds
- Topic: Comparing Strengths of Ionic & Covalent Bonds
- Replies: 2
- Views: 175
Re: Comparing Strengths of Ionic & Covalent Bonds
I think that, in general, covalent bonds are considered stronger than ionic bonds.
- Sun Nov 10, 2019 4:56 pm
- Forum: Ionic & Covalent Bonds
- Topic: polarizing power
- Replies: 7
- Views: 437
Re: polarizing power
Yes, they are essentially opposites, so they increase in opposite directions.
- Sun Nov 10, 2019 4:54 pm
- Forum: Lewis Structures
- Topic: Oxygen
- Replies: 8
- Views: 1110
Re: Oxygen
Yeah this was a tricky question on the midterm but because of the extra (4th) electron in the 2p subshell, oxygen has a slightly lower IE than nitrogen.
- Sun Nov 10, 2019 4:51 pm
- Forum: Lewis Structures
- Topic: Lewis structures that are not symmetrical
- Replies: 4
- Views: 576
Re: Lewis structures that are not symmetrical
I think for a single atom that has 5 electrons, it would still be considered nonpolar because the electrons move around the nucleus and end up being equally distributed, on average, around the because they move so fast around it.
- Sun Nov 10, 2019 4:47 pm
- Forum: Lewis Structures
- Topic: Midterm grades
- Replies: 26
- Views: 1445
Re: Midterm grades
In case you can't read the above responses, Lavelle said we'll get the midterms back on wednesday in lecture.
- Sun Nov 03, 2019 9:43 pm
- Forum: Trends in The Periodic Table
- Topic: Electronegativity
- Replies: 3
- Views: 242
Re: Electronegativity
oxygen has the higher electronegativity.
- Sun Nov 03, 2019 9:39 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: L quantum number
- Replies: 5
- Views: 421
Re: L quantum number
And ml can be any number between -l and l, so it's range would depend on the value of l, but if l=11, than ml can be anything btwn -11 and 11.
- Sun Nov 03, 2019 9:36 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: degenerate orbitals
- Replies: 3
- Views: 232
Re: degenerate orbitals
It's based off of which subshell the electron is in. For s, there is only one orbital. In p, there are three degenerate orbitals (px,py,pz). In d there are 5 and in f there are 7.
- Sun Nov 03, 2019 9:34 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: What are shells, subshells, sublevels, and orbitals?
- Replies: 2
- Views: 149
Re: What are shells, subshells, sublevels, and orbitals?
Shells are whether its 1/2/3/etc, the subshells is the s/p/d/f, and the orbitals are more specific for the subshells because all except for s have multiple trajectories that the electrons travel through. So for example, you could classify an electron as being in 1px, which covers all three levels- 1...
- Sun Nov 03, 2019 9:30 pm
- Forum: SI Units, Unit Conversions
- Topic: Do you always convert to SI units for calculations?
- Replies: 3
- Views: 302
Re: Do you always convert to SI units for calculations?
As long as the units are the same on each side, it doesn't really matter because you can always convert btwn the different ^10 levels. The only trouble is for units like Joules where its specifically kg, and as long as you know that (or the entirety of the joules unit breakdown), you're fine.
- Sun Oct 27, 2019 10:07 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy
- Replies: 4
- Views: 240
Re: Ionization Energy
You just have to memorize the periodic trends, with IE increasing from left to right and from top to bottom. So, Helium will have the highest ionization energy, meaning it is the least willing to lend an electron, while the bottom left atom will have the lowest, meaning it is the most willing to giv...
- Sun Oct 27, 2019 10:05 pm
- Forum: Trends in The Periodic Table
- Topic: Electronegativity vs. effective nuclear charge
- Replies: 5
- Views: 2094
Re: Electronegativity vs. effective nuclear charge
They are essentially opposites, being that electronegativity pulls on other atom's electrons vs. effective nuclear charge being the nucleus pulling in that atoms own electrons.
- Sun Oct 27, 2019 10:05 pm
- Forum: Trends in The Periodic Table
- Topic: Electronegativity vs. effective nuclear charge
- Replies: 5
- Views: 2094
Re: Electronegativity vs. effective nuclear charge
They are essentially opposites, being that electronegativity pulls on other atom's electrons vs. effective nuclear charge being the nucleus pulling in that atoms own electrons.
- Sun Oct 27, 2019 10:02 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: He+ ion
- Replies: 2
- Views: 121
Re: He+ ion
Yeah, the size of the atoms is different because of the periodic trends so the orbital location would be different even tho the shape is the same because its in the 1s orbital.
- Sun Oct 27, 2019 10:00 pm
- Forum: DeBroglie Equation
- Topic: Protons and Electrons
- Replies: 4
- Views: 288
Re: Protons and Electrons
Yes, they will have the same wavelength because all the variables in the equation are the same between protons and nuetrons if they are moving at the same velocity.
- Sun Oct 27, 2019 9:59 pm
- Forum: DeBroglie Equation
- Topic: 1.B.16
- Replies: 2
- Views: 152
Re: 1.B.16
Yup did the same thing and got the same answer as you guys.
- Sat Oct 19, 2019 8:32 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Memorizing electron configuration
- Replies: 3
- Views: 226
Re: Memorizing electron configuration
You add an electron with each atom going left to right, and if you memorize how many electrons go in each orbital, its easy to tell when you add a new level of orbital. Going from top to bottom, you just add a full set of orbitals
- Sat Oct 19, 2019 8:30 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Determining # of Subshells in an Orbital
- Replies: 3
- Views: 261
Re: Determining # of Subshells in an Orbital
Yeah its something that we just memorize because were in the basic level of chemistry, but I think that its based off the number of workable answers to the psi function for each orbital.
- Sat Oct 19, 2019 8:26 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: 3d and 4s
- Replies: 4
- Views: 157
Re: 3d and 4s
For all but two of the atoms in that area and row of the periodic table (silver and one other in the first row), 4s just happens to be the lower energy orbital so its filled first. When both are full 3d has lower energy, but with empty orbitals, 4s is a lower energy state than 3d.
- Sat Oct 19, 2019 8:24 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: P Orbital specifics
- Replies: 4
- Views: 186
Re: P Orbital specifics
Lavelle said in class that it is arbitrary which axis is which, because like you said it depends on the point of view. We put it in the x first out of convenience and its standard, but no there isn't a defined x, y, and z axis.
- Sat Oct 19, 2019 8:22 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: More Orbital Understanding
- Replies: 3
- Views: 171
Re: More Orbital Understanding
Not totally sure, but I think that the probability is uniform because of the energy of the electrons going around the orbital, and at that point the pull from the nucleus doesn't make a difference in the location of the electron.
- Sun Oct 13, 2019 3:31 pm
- Forum: Einstein Equation
- Topic: 1B.15 c)
- Replies: 3
- Views: 222
Re: 1B.15 c)
The first one (a) is asking about the wavelength of the electron, and I think that (c) is asking about the wavelength of the photon that caused the electron to be ejected
- Sun Oct 13, 2019 3:29 pm
- Forum: Photoelectric Effect
- Topic: ejecting electons
- Replies: 6
- Views: 228
Re: ejecting electons
What they said, no each photon interacts with just one electron with the excess energy being released, not applied to other electrons
- Sun Oct 13, 2019 3:26 pm
- Forum: Trends in The Periodic Table
- Topic: Chemistry Community
- Replies: 8
- Views: 495
Re: Chemistry Community
If you go to your own profile it shows you how many times you've posted on here
- Sun Oct 13, 2019 3:23 pm
- Forum: Properties of Electrons
- Topic: Mass of Electrons
- Replies: 6
- Views: 307
Re: Mass of Electrons
It's always the same.
- Sun Oct 13, 2019 3:21 pm
- Forum: Properties of Light
- Topic: 1B.19
- Replies: 2
- Views: 175
Re: 1B.19
By that it means the proportion of the proton's wavelength to the neutron's. As in divide the proton's by the neutrons
- Tue Oct 08, 2019 5:41 pm
- Forum: Empirical & Molecular Formulas
- Topic: Chemical Formulas
- Replies: 3
- Views: 273
Chemical Formulas
Does anyone know if we have to know the english names for chemical formulas on the test? (ex ethene) .
- Sun Oct 06, 2019 3:03 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Showing work in detail
- Replies: 7
- Views: 634
Re: Showing work in detail
It's probably not essential, but it can't hurt to have them on there in case. Its a little bit of an inconvenience but it doesn't make the problem any harder
- Sun Oct 06, 2019 3:02 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test Equation Sheet
- Replies: 8
- Views: 454
Re: Test Equation Sheet
Yes, I think you guys are correct that we will get the important formulas given to us on the test so we don't have to memorize all of them, but it prob helps to know at least the most important ones just in case.
- Sun Oct 06, 2019 3:00 pm
- Forum: Significant Figures
- Topic: Sig Fig Test Importance
- Replies: 2
- Views: 165
Sig Fig Test Importance
Do we have to work with sig figs on the test? Because in discussion we just skipped over them because they're kinda unnecessary, but we learned them so and theyre in the textbook
- Sun Oct 06, 2019 2:56 pm
- Forum: SI Units, Unit Conversions
- Topic: SI Units
- Replies: 3
- Views: 141
Re: SI Units
There are technically prefixes for every different level, but I think we usually work in every three because it's a lot easier to remember. Having a number be to three places or two decimals isnt the end of the world, so I think that is easier than memorizing every single place.