Search found 105 matches
- Fri Mar 12, 2021 10:45 am
- Forum: Second Order Reactions
- Topic: Determining slow step
- Replies: 22
- Views: 1215
Re: Determining slow step
You look at the overall reaction. Anything that isn't in the overall reaction is an intermediate.
- Fri Mar 12, 2021 10:45 am
- Forum: Experimental Details
- Topic: Fast step at equilibrium [ENDORSED]
- Replies: 4
- Views: 573
Re: Fast step at equilibrium [ENDORSED]
The first step was a fast step and right after it was the slow step. Since the slow step takes longer to happen, in that time, for the fast step, there is a buildup of products which will go in the reverse and form reactants. This is the assumption we're making in the pre-equilibrium approach. In th...
- Fri Mar 12, 2021 10:43 am
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Gibbs Energy
- Replies: 20
- Views: 1156
Re: Gibbs Energy
Gibbs Free Energy relates to thermodynamics because it represents the amount of energy that can be used for the reaction. The equation for Gibbs Free Energy relates it to enthalpy, temperature, and entropy. It doesn't have to do with kinetics because it doesn't tell you how fast or slow the reaction...
- Fri Mar 12, 2021 10:42 am
- Forum: General Rate Laws
- Topic: liquids and solids
- Replies: 6
- Views: 475
Re: liquids and solids
I think it would probably be specified in the question and they should be in the same phase.
- Fri Mar 12, 2021 10:40 am
- Forum: Student Social/Study Group
- Topic: How are y'all doing?
- Replies: 46
- Views: 2780
Re: How are y'all doing?
I feel that. It's so hard to stay motivated right now but I've just been taking it day by day. Good luck on finals everyone!!
- Sat Mar 06, 2021 8:52 pm
- Forum: First Order Reactions
- Topic: Graphing
- Replies: 20
- Views: 1008
Re: Graphing
We aren't going to be plotting graphs since the test is multiple choice but he probably wants us to know what's on the y-axis for the zero, first, and second order graphs.
- Sat Mar 06, 2021 8:51 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: reaction energy barrier
- Replies: 10
- Views: 810
Re: reaction energy barrier
Every reaction needs to reach a transitional state which requires a large amount of energy and that's called the energy barrier or activation energy. When we talk about a reaction being spontaneous, we're only talking about the difference in free energy between the products and reactants so we compl...
- Sat Mar 06, 2021 8:48 pm
- Forum: General Rate Laws
- Topic: Integrated Rate Law
- Replies: 7
- Views: 445
Re: Integrated Rate Law
The Integrated Rate Law lets you figure out the rate of the reaction at a single time. In other words, it gives you the instantaneous rate. The reason it specifies the products are being removed is because if the products were part of the reaction, the reverse reaction could occur and the reactant c...
- Sat Mar 06, 2021 8:45 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell notation
- Replies: 12
- Views: 757
Re: cell notation
Yes, that's correct! Electrons move from left to right.
- Sat Mar 06, 2021 8:45 pm
- Forum: Balancing Redox Reactions
- Topic: Oxidizing Agent
- Replies: 33
- Views: 1356
Re: Oxidizing Agent
Oxidizing agent is the one getting reduced and you determine strength by looking at standard reduction potential so if it is low, it's a poor oxidizing agent.
- Sun Feb 28, 2021 11:34 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta U=0
- Replies: 17
- Views: 2685
Re: delta U=0
delta U is 0 for an isothermal reversible expansion since the amount of energy lost from work is replaced by heat. q= -w
- Sun Feb 28, 2021 11:33 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: work
- Replies: 21
- Views: 1041
Re: work
When work is done on the system, it is positive and when work is done BY the system it is negative since the system is using energy to do work. Hope that makes sense!
- Sun Feb 28, 2021 11:32 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: H vs q
- Replies: 20
- Views: 936
Re: H vs q
H and q are the same under constant pressure. Otherwise, you'd get to different values for each. I'm not entirely sure how they're different conceptually.
- Sun Feb 28, 2021 11:31 pm
- Forum: Calculating Work of Expansion
- Topic: Equations
- Replies: 4
- Views: 349
Re: Equations
it depends on whether pressure is constant or not. You can use -P(delta)V when external pressure is constant and the other when it isn't.
- Sun Feb 28, 2021 11:30 pm
- Forum: Calculating Work of Expansion
- Topic: identifying when to use w
- Replies: 5
- Views: 441
Re: identifying when to use w
This depends on whether pressure is constant or not. You can use -P(delta)V when external pressure is constant.
- Sun Feb 21, 2021 12:12 pm
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy vs heat
- Replies: 31
- Views: 2625
Re: Enthalpy vs heat
Enthalpy is equal to heat under constant pressure.
- Sun Feb 21, 2021 12:11 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: deltaU=deltaH+w
- Replies: 8
- Views: 676
Re: deltaU=deltaH+w
deltaH equals q under constant pressure.
- Sun Feb 21, 2021 12:10 pm
- Forum: Phase Changes & Related Calculations
- Topic: Vapor vs gas
- Replies: 121
- Views: 12583
Re: Vapor vs gas
I'm pretty sure they're the same thing.
- Sun Feb 21, 2021 12:09 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Property
- Replies: 71
- Views: 3287
Re: State Property
Internal energy (U) is a state property because you'll get the same result no matter what path you take. It only matters what your initial state was and what your final state was.
- Sun Feb 21, 2021 11:57 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Extensive and Intensive Properties, and State Functions
- Replies: 4
- Views: 4193
Re: Extensive and Intensive Properties, and State Functions
An extensive property is a property that changes with the size of the sample. Heat capacity is an extensive property because if you have more of the sample, it will take more heat to change the temperature. An intensive property is a property that doesn't change with the size of the sample. Specific...
- Sun Feb 14, 2021 11:51 am
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: internal energy ideal gas
- Replies: 5
- Views: 376
Re: internal energy ideal gas
The work done is replaced by heat so Q = -W. Since delta U = Q + W, it would be 0.
- Sun Feb 14, 2021 11:49 am
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Kelvin conversion
- Replies: 40
- Views: 3422
Re: Kelvin conversion
In his examples in class, he just uses 273 so I think that should be fine.
- Sun Feb 14, 2021 11:48 am
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: R Constant
- Replies: 91
- Views: 6793
Re: R Constant
When there's pressure and volume involved in the calculation, I use the R constant that includes atm and L in the units. You just have to check the units and make sure it cancels out to get you the final units you need.
- Sun Feb 14, 2021 11:47 am
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Units of W
- Replies: 16
- Views: 831
Re: Units of W
There are no units. It's just a measure of the number of possible states I believe.
- Sun Feb 14, 2021 11:46 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Likeliness to form products/reactants
- Replies: 27
- Views: 986
Re: Likeliness to form products/reactants
If delta G is negative, the forward reaction is favored so it will form products.
- Sun Feb 07, 2021 11:18 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE Chart Question
- Replies: 26
- Views: 1612
Re: ICE Chart Question
2x is considered to be the concentration of that compound. When you calculate K, you do each concentration to the power of it's stoichiometric coefficient so it would be (2x)^n. The exponent would be on the 2 as well.
- Sun Feb 07, 2021 11:16 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: percent ionization
- Replies: 7
- Views: 3734
Re: percent ionization
Percent protonation/deprotonation compares the H3O+ concentration or OH- concentration with the initial concentration. Percent ionization compares the ion concentration to the initial concentration. They can be similar. It depends on the context.
- Sun Feb 07, 2021 11:14 pm
- Forum: Ideal Gases
- Topic: Chem BL
- Replies: 107
- Views: 8901
Re: Chem BL
I'm taking Chem BL right now. You can honestly take it whenever, not just with Chem 14B. There are concepts from Chem 14A that you need to remember but nothing too complex. It'll be pretty easy to review those so you don't need to take it right after.
- Sun Feb 07, 2021 11:13 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: pH of .005 M AlCl3
- Replies: 3
- Views: 373
Re: pH of .005 M AlCl3
Al has a charge of 3+ and is able to form a coordination compound. When it binds to water, it weakens the existed OH bond in water which leads to an H+ being released.
- Sun Feb 07, 2021 11:12 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Effect of Pressure (contraction) in reaction
- Replies: 8
- Views: 359
Re: Effect of Pressure (contraction) in reaction
It would shift to the left since by compressing the system, you are increasing the pressure. The left has less moles of gas. By shifting the equilibrium to the left, more solid reactant would be made and decrease the pressure of the system.
- Sat Jan 30, 2021 5:27 pm
- Forum: Ideal Gases
- Topic: Partial Pressure
- Replies: 6
- Views: 364
Re: Partial Pressure
Partial pressure refers to how much of the total pressure is occupied by one gas so we call it partial pressure of that gas since that is occupying that "part" of the pressure.
- Sat Jan 30, 2021 5:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Making X negligible
- Replies: 34
- Views: 1494
Re: Making X negligible
When K is less 10^-4 is what Lavelle said in lecture but he also said to check the percent ionization so divide x by the initial concentration and if it's less than 5%, the assumption is okay.
- Sat Jan 30, 2021 5:23 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Cubic Equations
- Replies: 6
- Views: 370
Re: Cubic Equations
Simplifying it probably refers to using the assumption.
- Sat Jan 30, 2021 5:22 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: is HClO3 weak or strong? [ENDORSED]
- Replies: 49
- Views: 4476
Re: is HClO3 weak or strong? [ENDORSED]
This is also a strong acid.
- Sat Jan 30, 2021 5:21 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Memorize bond enthalpies / standard enthalpies of formation?
- Replies: 39
- Views: 1418
Re: Memorize bond enthalpies / standard enthalpies of formation?
No, this information will probably be given in the question on the test since it's not on our constants & equations sheet.
- Sat Jan 30, 2021 5:20 pm
- Forum: Phase Changes & Related Calculations
- Topic: when to assume x is insignificant
- Replies: 86
- Views: 7837
Re: when to assume x is insignificant
Less than 10^-3 but Lavelle said when k is less than 10^-4 to be safe; also if you divide x by the initial concentration and get less than 5%, you know that your assumption is ok.
- Sat Jan 30, 2021 5:18 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endothermic v. Exothermic
- Replies: 139
- Views: 15344
Re: Endothermic v. Exothermic
Yes, endothermic will be positive since it is absorbing heat and exothermic will be negative since it is releasing heat.
- Sun Jan 24, 2021 11:36 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When to use ICE box
- Replies: 23
- Views: 952
Re: When to use ICE box
Yes, equilibrium composition means equilibrium concentrations. You use the ICE box when you are given initial concentrations and you need to find K or the equilibrium concentrations.
- Sun Jan 24, 2021 11:35 pm
- Forum: Ideal Gases
- Topic: Gas Constant Value
- Replies: 43
- Views: 1753
Re: Gas Constant Value
You would have the check the pressure units to figure out what constant to use and you don't need to memorize them because they can all be found on the Constants & Equations Sheet on Lavelle's website.
- Sun Jan 24, 2021 11:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Clarification for Sampling #7
- Replies: 10
- Views: 588
Re: Clarification for Sampling #7
It identifies it as a weak base so you would need to find Kb. You can do this by using the formula Ka x Kb = Kw so you would just divide 1.0 x 10^-14 by the given Ka.
- Sun Jan 24, 2021 11:33 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Determining pH
- Replies: 18
- Views: 854
Re: Determining pH
If you take the -log of the hydronium ion concentration (H3O+, or H+), you will get pH and if you take the -log of the hydroxide ion concentration (OH-), you will get pOH.
- Sun Jan 24, 2021 11:31 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Sapling 9
- Replies: 10
- Views: 403
Re: Sapling 9
If the pH is less, the solution the acid is in is more acidic so it won't deprotonate in the solution. The solution already has a high hydrogen ion concentration so it won't be able to add hydrogen ions easily which is why it remains neutral.
- Sun Jan 17, 2021 2:42 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure Rule
- Replies: 29
- Views: 1505
Re: Pressure Rule
You only look at molecules in the gas phase since those are the one's whose concentration is affected by a change in pressure. However, this change in pressure must cause a change in the volume of the container. If the pressure is changed by adding another gas, it won't affect the concentrations of ...
- Sun Jan 17, 2021 2:41 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Ka x Kb
- Replies: 11
- Views: 404
Re: Ka x Kb
Yes! This is because when you multiple the two, the other reactants and products will cancel out and you will be left with [H3O+][OH-] which is the equation for Kw.
- Sun Jan 17, 2021 2:39 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: q vs k
- Replies: 62
- Views: 2776
Re: q vs k
If Q = K, the reaction is at equilibrium.
- Sun Jan 17, 2021 2:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Amphiprotic
- Replies: 8
- Views: 375
Re: Amphiprotic
Amphiprotic means it can act as both a proton donor or acceptor. Water is an example because it can donate an H+ and become OH- or it can accept an H+ and become H3O+.
- Sun Jan 17, 2021 2:37 pm
- Forum: Ideal Gases
- Topic: Does temperature matter?
- Replies: 19
- Views: 606
Re: Does temperature matter?
When the temperature changes, K will change. These problems usually give us a temperature to let us know that the reaction is occurring at the same temperature as K is being reported at.
- Sun Jan 10, 2021 10:47 pm
- Forum: Ideal Gases
- Topic: value of R
- Replies: 24
- Views: 1077
Re: value of R
You look at the units of R. It depends on what units of pressure you're using.
- Sun Jan 10, 2021 10:46 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure and Volume
- Replies: 16
- Views: 832
Re: Pressure and Volume
For me, it's easy to understand the relationship between the two when you look at a balloon. If you have a large balloon (high volume), the particles inside have a lot more area to move around in which is why there's lower pressure. If the balloon is smaller, the particles are moving around in a sma...
- Sun Jan 10, 2021 10:44 pm
- Forum: Ideal Gases
- Topic: PV=nRT
- Replies: 74
- Views: 4841
Re: PV=nRT
P: pressure
V: volume
n: moles
R: R constant
T: temperature
V: volume
n: moles
R: R constant
T: temperature
- Sun Jan 10, 2021 10:43 pm
- Forum: Ideal Gases
- Topic: reversing reactions
- Replies: 83
- Views: 5586
Re: reversing reactions
K is products over reactants so if you use the reverse reaction, K would be the reactants over the products. That's why K (reverse) is 1/K (forward)
- Sun Jan 10, 2021 10:42 pm
- Forum: Ideal Gases
- Topic: partial pressures
- Replies: 14
- Views: 440
Re: partial pressures
Partial pressures is the pressure of each individual gas. When all the partial pressures are added up, you get the total pressure. It can be convereted to concentration (which is measured in mol/L) using the ideal gas law: PV = nRT --> you solve to get n/V which would be mol/L.
- Thu Dec 10, 2020 9:58 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Transition Metal Complexes
- Replies: 5
- Views: 288
Re: Transition Metal Complexes
Whether it is tetrahedral or octohedral depends on the number of ligands it is bonded two, 4 for tetrahedral/square planer and 6 for octohedral.
- Thu Dec 10, 2020 9:54 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: AX3E2
- Replies: 7
- Views: 653
Re: AX3E2
This is what I got from the lecture. If the lone pairs are on the top and bottom, they'll be 90 degrees away from all the other bonds which is not the best for them to be as far away as possible. You want them to be as far away are possible so the lone pairs are kind angled in the axis in three dime...
- Thu Dec 10, 2020 9:48 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Chem Final
- Replies: 7
- Views: 405
Re: Chem Final
2F has to do with the Molecular Shape unit so it wasn't on Midterm 2. Midterm 2 had upto 2D which had to do with Chemical Bonds.
- Thu Dec 10, 2020 9:46 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Kate's Molecular Shape and Hybridization Review
- Replies: 2
- Views: 198
Re: Kate's Molecular Shape and Hybridization Review
Thank you so much Kate! I learned a lot from you this quarter!!
- Thu Dec 10, 2020 6:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Matthew's Workshop - Week 10
- Replies: 2
- Views: 977
Re: Matthew's Workshop - Week 10
Thank you so much Matthew! I learned a lot from you this quarter!!
- Thu Dec 10, 2020 2:50 am
- Forum: Biological Examples
- Topic: Final Exam
- Replies: 8
- Views: 615
Re: Final Exam
During the workshop I attended, the UA said to know about cisplatin and the heme complex.
- Thu Dec 03, 2020 10:47 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: d vs s orbitals
- Replies: 7
- Views: 1054
Re: d vs s orbitals
They don't contradict each other because s orbitals have lower energy, so that's why electrons are added to 4s before 3d and since they have lower energy, they are easy to remove so when a cation is formed, they are removed from 4s orbitals.
- Thu Dec 03, 2020 10:43 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Sigma and Pi Bonds
- Replies: 33
- Views: 1706
Re: Sigma and Pi Bonds
Based on the outline, I don't think we'll be asked this on the test.
- Thu Dec 03, 2020 10:42 pm
- Forum: Hybridization
- Topic: Difference between hybrid orbitals and hybridization
- Replies: 5
- Views: 1203
Re: Difference between hybrid orbitals and hybridization
The hybrid orbital specifies the principal quantum number (n) of the orbital.
- Thu Dec 03, 2020 10:41 pm
- Forum: Hybridization
- Topic: Why do double bonds (and triple bonds) count as one region of electron density?
- Replies: 8
- Views: 1801
Re: Why do double bonds (and triple bonds) count as one region of electron density?
Whether it's a double bond or a single bond, there is only one hybrid orbital that will participate in a sigma bond. The other bonds come from overlapping p-orbitals (pi bonds). This is why you only count it as one region of electron density.
- Thu Dec 03, 2020 9:49 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Finding Coordination Number
- Replies: 14
- Views: 659
Re: Finding Coordination Number
The coordination number is the number of bonds the transition metal forms.
- Sun Nov 29, 2020 8:13 pm
- Forum: Hybridization
- Topic: Definition of Hybridization
- Replies: 5
- Views: 316
Re: Definition of Hybridization
Hybridization is the mixing of orbitals and it happens when an atom binds with other atoms so you can't tell what the hydridization will be from the electron configuration of the atom alone.
- Sun Nov 29, 2020 8:12 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: delocalized pi bond
- Replies: 8
- Views: 539
Re: delocalized pi bond
A delocalized pi bond is present in a molecule that has resonance because the e- are delocalized.
- Sun Nov 29, 2020 8:11 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: sigma vs pi bonds
- Replies: 33
- Views: 2162
Re: sigma vs pi bonds
Single bonds are sigma bonds and double bonds have one sigma and one pi bond. The difference is that in sigma bonds, the ends of the orbitals overlap and in pi bonds, parallel orbitals overlap side to side.
- Sun Nov 29, 2020 8:09 pm
- Forum: Octet Exceptions
- Topic: Expansion for 3s?
- Replies: 4
- Views: 271
Re: Expansion for 3s?
No, it would need to have a d-orbital and atoms in 3s don't use the d-orbital.
- Sun Nov 29, 2020 8:07 pm
- Forum: Electronegativity
- Topic: Calculating elctronegativity
- Replies: 8
- Views: 458
Re: Calculating elctronegativity
You don't need to know the values, you should just know the periodic trends.
- Sun Nov 29, 2020 8:07 pm
- Forum: Dipole Moments
- Topic: Polarity from Shape
- Replies: 12
- Views: 737
Re: Polarity from Shape
It doesn't need to be bent. You have to check whether the dipole moments cancel out on the sides of the molecule.
- Sun Nov 29, 2020 8:05 pm
- Forum: Bond Lengths & Energies
- Topic: Hydrogen Bonds
- Replies: 17
- Views: 901
Re: Hydrogen Bonds
No, hydrogen bonds require hydrogen bonding with an electronegative atom.
- Sun Nov 29, 2020 8:05 pm
- Forum: Resonance Structures
- Topic: Same formal charges, which resonance structure?
- Replies: 4
- Views: 347
Re: Same formal charges, which resonance structure?
The more electronegative atom would have the negative formal charge.
- Mon Nov 16, 2020 12:48 am
- Forum: Dipole Moments
- Topic: Which interactions are intermolecular?
- Replies: 7
- Views: 410
Re: Which interactions are intermolecular?
Yes they are. Intermolecular forces hold separate molecules together and intramolecular forces are forces that hold a single molecule together.
- Mon Nov 16, 2020 12:46 am
- Forum: Electronegativity
- Topic: determining electronegativity
- Replies: 40
- Views: 5909
Re: determining electronegativity
Electronegativity increases as you go to the right and it decreases as you go down on the periodic table.
- Mon Nov 16, 2020 12:45 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Spin State
- Replies: 8
- Views: 843
Re: Spin State
I don't think we need to know about the specifics of how we got the value exactly; just that + means upward spin and - means downward spin.
- Mon Nov 16, 2020 12:44 am
- Forum: Bond Lengths & Energies
- Topic: Valence electrons of nitrogen
- Replies: 10
- Views: 464
Re: Valence electrons of nitrogen
He was referring to the octet rule. It has 5 valence electrons but it wants 8.
- Mon Nov 16, 2020 12:44 am
- Forum: Dipole Moments
- Topic: London Dispersion Forces
- Replies: 4
- Views: 180
Re: London Dispersion Forces
They happen for all: both nonpolar and polar molecules.
- Mon Nov 16, 2020 12:43 am
- Forum: Ionic & Covalent Bonds
- Topic: Workshop Hydrogen Bonding Question
- Replies: 4
- Views: 762
Re: Workshop Hydrogen Bonding Question
There is not that great of an electronegativity different between C and H for it to be a polar bond.
- Sun Nov 08, 2020 11:30 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Lengths
- Replies: 10
- Views: 865
Re: Bond Lengths
I'm not sure what your question is asking exactly but just a trend to know is that double bonds are shorter than single bonds.
- Sun Nov 08, 2020 11:28 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: subshells and orbitals
- Replies: 9
- Views: 2218
Re: subshells and orbitals
I think subshell is the combination of the shell and the which orbital it is (which would be represented by l). I'm not sure if this is the best way of explaining it.
- Sun Nov 08, 2020 11:26 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal charges and stability
- Replies: 5
- Views: 337
Re: Formal charges and stability
It probably depends on the situation but I would say it's probably more stable to have it spread out since you don't want a lot of electrons in one region since that leads to electron-electron repulsions.
- Sun Nov 08, 2020 11:25 pm
- Forum: Lewis Structures
- Topic: octet rule
- Replies: 7
- Views: 261
Re: octet rule
There are certain times when it can be violated such as P and I which are exceptions because they have an expanded valence orbital. These are just exceptions we'll have to memorize.
- Sun Nov 08, 2020 11:24 pm
- Forum: Sigma & Pi Bonds
- Topic: Hybridization for p
- Replies: 4
- Views: 277
Re: Hybridization for p
Pi bonds do not use hybridization. They are formed by overlapping p-orbitals.
- Sun Nov 08, 2020 11:22 pm
- Forum: Ionic & Covalent Bonds
- Topic: Atomic Radii
- Replies: 5
- Views: 295
Re: Atomic Radii
The 2p orbital is on the second shell which means the radius is increasing. Since there are more electrons, there is more repulsion between them so the radius increases.
- Mon Nov 02, 2020 12:01 am
- Forum: *Shrodinger Equation
- Topic: Sapling week 2/3
- Replies: 12
- Views: 1330
Re: Sapling week 2/3
Hi! This question has to do with Heisenberg Uncertainty/Indeterminacy principle.
- Mon Nov 02, 2020 12:00 am
- Forum: Photoelectric Effect
- Topic: Kinetic Energy
- Replies: 10
- Views: 627
Re: Kinetic Energy
I feel like that should be true since higher frequency means more energy but maybe it's because the frequency isn't enough to eject the electron. I'm not sure if there were any additional details given in the question.
- Sun Nov 01, 2020 11:58 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation for ions?
- Replies: 4
- Views: 692
Re: Rydberg Equation for ions?
This works for hydrogen only. There are some "corrections" that need to be made when doing this for other elements. I'm pretty sure we're just focusing on hydrogen but there's some information on this in the textbook.
- Sun Nov 01, 2020 11:57 pm
- Forum: *Particle in a Box
- Topic: Energy Equations
- Replies: 13
- Views: 1086
Re: Energy Equations
This would be determined based on what information is given in the question.
- Sun Nov 01, 2020 11:55 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Participation Points [ENDORSED]
- Replies: 62
- Views: 3902
Re: Participation Points [ENDORSED]
Any post or reply counts for participation points. You can click on your name to see how many posts you did and the day they were posted.
- Sun Oct 25, 2020 11:47 pm
- Forum: *Particle in a Box
- Topic: Midterm 1
- Replies: 17
- Views: 1407
Re: Midterm 1
Hi! We will not be tested on the particle in a box on the midterm. Dr Lavelle said in his lecture today that our midterm will only go up to the last slide he did which introduced the different atomic orbitals and did not discuss a particle in a box. In general, our midterm will only contain all the...
- Sun Oct 25, 2020 11:45 pm
- Forum: Balancing Chemical Reactions
- Topic: States of matter in chem equations
- Replies: 13
- Views: 1032
Re: States of matter in chem equations
Samin Kabir wrote:Hello,
When we have to balance chem equations do we have to include the states of matter in all components. Additionally how do we know what state of matter a reactant/product is in?
I would add it in just to be safe and it should be given in the question.
- Sun Oct 25, 2020 11:44 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: Solute vs Solvent
- Replies: 6
- Views: 806
Re: Solute vs Solvent
Hi! What makes something a solvent or a solute? How can we just know? I know that solutes are dissolved in solvents to create a solution such as salt and water, respectively. However, if given two items, how would I know? What makes something soluble I guess? I don't think his questions will go sup...
- Sun Oct 25, 2020 11:43 pm
- Forum: SI Units, Unit Conversions
- Topic: units to know for midterm
- Replies: 11
- Views: 818
Re: units to know for midterm
905579227 wrote:Do you guys know what will be allowed on the midterm? Also do we have to memorize the conversions or will that be provided.
The conversions will be provided. I would say you should memorize the electromagnetic spectrum and the prefixes like giga- , mega- etc.
- Sun Oct 25, 2020 11:40 pm
- Forum: *Shrodinger Equation
- Topic: Schrodinger on MT
- Replies: 7
- Views: 462
Re: Schrodinger on MT
I believe we just need to know the relationship between Schrodinger's and orbitals.
- Sun Oct 18, 2020 4:05 pm
- Forum: Photoelectric Effect
- Topic: What happens to absorbed photons?
- Replies: 6
- Views: 482
Re: What happens to absorbed photons?
I'm not entirely sure but since they've given up all their energy to the electron, I think they just get destroyed in the process.
- Sun Oct 18, 2020 4:02 pm
- Forum: SI Units, Unit Conversions
- Topic: Metric Conversions
- Replies: 9
- Views: 1782
Re: Metric Conversions
hi! Mine is kind of weird. I do: the G reat M aster K night D id C ommit M urder U nder N o P retenses. G - giga M - mega K - kilo D - deci C - centi M - milli u - micro n - nano p -pico It is so weird that I have no trouble remembering it. I don't remember where it is from, but it works. :) Whoa! ...
- Sun Oct 18, 2020 4:00 pm
- Forum: Balancing Chemical Reactions
- Topic: Mixed Numbers
- Replies: 7
- Views: 357
Re: Mixed Numbers
Your final answer should have whole number coefficients.
- Sun Oct 18, 2020 3:59 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Test Accuracy
- Replies: 13
- Views: 840
Re: Test Accuracy
I believe this depends on how strict your TA is on sig figs but I would round to the correct number of sig figs on your final answer based on the numbers given to you in the problem just to be safe.
- Sun Oct 18, 2020 3:57 pm
- Forum: Properties of Electrons
- Topic: protons and electrons
- Replies: 33
- Views: 2684
Re: protons and electrons
Protons and neutrons have similar masses and electrons have a much lower mass than protons and neutrons.
- Sun Oct 18, 2020 3:55 pm
- Forum: Limiting Reactant Calculations
- Topic: Exam Material
- Replies: 2
- Views: 202
Re: Exam Material
Also, for the external camera, I believe it's okay to use a phone.
- Thu Oct 08, 2020 1:35 pm
- Forum: Limiting Reactant Calculations
- Topic: How do we find the amount of oxygen in combustion?
- Replies: 10
- Views: 4671
Re: How do we find the amount of oxygen in combustion?
I'm not sure if this is what you're asking but once you find the mass of carbon and hydrogen, you can subtract that from the mass of the original compound to find the mass of oxygen.