## Search found 101 matches

Sat Mar 14, 2020 2:20 pm
Forum: Student Social/Study Group
Topic: Review Sessions
Replies: 4
Views: 132

### 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: 749

### Re: Coronavirus Joke

Solid.
Sat Mar 14, 2020 2:17 pm
Forum: Student Social/Study Group
Topic: Week 10 Review Question
Replies: 5
Views: 153

### 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: 31
Views: 1408

### 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
Replies: 1
Views: 94

### 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: 52

### 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: 80

### 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: 90

### 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: 58

### 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: 135
Views: 33652

### 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: 77

### 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: 115

### 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: 71

### 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: 91

### 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: 48

### 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: 49

### 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: 55

### 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: 66

### 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: 365

### 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: 12
Views: 266

### 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: 140

### 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: 78

### 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: 51

### 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: 107

### 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
Replies: 67
Views: 2851

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
Replies: 67
Views: 2851

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: 103

### 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: 48

### 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: 51

### 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: 62

### 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: 85

### 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: 78

### 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: 88

### 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: 73

### 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: 220

### 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
Replies: 73
Views: 3860

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: 174

### 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: 56

### 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: 78

### 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: 64

### 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: 122

### 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: 34

### 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: 38

### 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: 141

### 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: 42

### 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: 3
Views: 45

### 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: 68

### 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: 70

### 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: 70

### 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: 38

### 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: 192

### 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: 72

### 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: 99

### 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: 62

### 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
Sun Dec 01, 2019 2:21 pm
Forum: Lewis Acids & Bases
Topic: Lewis Acids
Replies: 3
Views: 54

### 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: 53

### 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: 127

### 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: 34

### 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: 27

### 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: 254

### 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: 16
Views: 341

### 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: 179

### 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: 4
Views: 170

### 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: 99

### 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: 15
Views: 262

### 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: 8
Views: 222

### 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: 35

### 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: 50

### 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: 62

### 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: 55

### 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: 74

### 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: 94

### 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: 97

### 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
Replies: 26
Views: 477

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: 64

### 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: 193

### 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: 52

### 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: 55

### 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: 166

### 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: 57

### 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: 69

### 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: 69

### 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: 51

### 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: 74

### 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: 50

### 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: 77

### 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: 55

### 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: 66

### 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: 45

### 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: 71

### 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: 114

### 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: 76

### 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: 148

### 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: 57

### 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: 77

### 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: 85

### 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: 306

### 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: 144

### 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: 59

### 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: 87

### 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.