Search found 101 matches
- Sun Mar 14, 2021 9:43 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Q and K
- Replies: 16
- Views: 826
Re: Q and K
Q and K are very similar, with the difference being that K is ONLY at equilibrium, while Q can be at any point during the reaction, including equilibrium
- Sun Mar 14, 2021 9:41 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Determining The Favored Side of an Equilibrium Product
- Replies: 12
- Views: 1291
Re: Determining The Favored Side of an Equilibrium Product
The way I remember it is when looking at Q >,<, or = K, the way the open end of the sign is facing is which side is favored.
- Sun Mar 14, 2021 9:39 pm
- Forum: Ideal Gases
- Topic: Torr as a Unit of Pressure
- Replies: 8
- Views: 858
Re: Torr as a Unit of Pressure
Additionally, the torr unit is also interchangeable with mmHg
- Sun Mar 14, 2021 9:37 pm
- Forum: Ideal Gases
- Topic: Reversing Reactions
- Replies: 68
- Views: 2740
Re: Reversing Reactions
Additionally, when multiplying a whole equation, its K is raised that power as well.
- Sun Mar 14, 2021 9:36 pm
- Forum: Ideal Gases
- Topic: K and Q
- Replies: 57
- Views: 3948
Re: K and Q
K is Q at equilibrium, whereas Q can be either at equilibrium or not
- Sun Mar 07, 2021 4:50 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: kinetics vs. thermodynamics
- Replies: 23
- Views: 1330
Re: kinetics vs. thermodynamics
While thermodynamics focuses on the initial and final energy/stability, kinetics focuses on throughout the entire reaction, primarily on the speed
- Sun Mar 07, 2021 3:40 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: what does E notch tell us compared to the E of a cell?
- Replies: 8
- Views: 386
Re: what does E notch tell us compared to the E of a cell?
To get from E naught to E of a cell, one can use the equation given with the E naught and the states of the system that are not standard
- Sun Mar 07, 2021 3:38 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Concentration Cells at Equilibrium
- Replies: 7
- Views: 412
Re: Concentration Cells at Equilibrium
The goal of a given concentration cell is to reach equilibrium, and in the process creating a voltage. Therefore, they are not necessarily at equilibrium in the beginning, but will strive to reach it
- Sun Mar 07, 2021 3:33 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: cell notation
- Replies: 12
- Views: 779
Re: cell notation
Additionally, on the sapling from last week there was a question which said a certain substance had to be next to the salt bridge, but I don't know if he will test on that
- Sun Mar 07, 2021 3:17 pm
- Forum: Balancing Redox Reactions
- Topic: Half-Reactions
- Replies: 11
- Views: 658
Re: Half-Reactions
I would assume that any half reactions not directly given to us can be either derived from the rate law equations or found using the molar ratios
- Sun Feb 28, 2021 11:11 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: E naught = 0
- Replies: 13
- Views: 2049
Re: E naught = 0
Reaction concentrations of concentration cells are equal on both sides, so the potential just becomes zero
- Sun Feb 28, 2021 10:58 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Sapling week 7/8 question #17
- Replies: 5
- Views: 329
Re: Sapling week 7/8 question #17
You can do this because the partial pressure of a gas can be considered as the "concentration" of the gas, hope this helps!
- Sun Feb 28, 2021 10:56 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n in ∆G = -nFE
- Replies: 80
- Views: 5055
Re: n in ∆G = -nFE
In previous concepts, n signified number of moles of reactant/product. In this chapter, n would actually signify the number of moles of electrons transferred between.
- Sun Feb 28, 2021 10:55 pm
- Forum: Balancing Redox Reactions
- Topic: Sapling Week 7/8 #5
- Replies: 9
- Views: 515
Re: Sapling Week 7/8 #5
For the second question, it takes place in basic solution, so you need to use OH- instead of H+
- Sun Feb 28, 2021 10:40 pm
- Forum: Balancing Redox Reactions
- Topic: Week8 Sapling #3
- Replies: 3
- Views: 292
Re: Week8 Sapling #3
For acidic reactions, you would use H+, and for basic reactions you would use OH-. Both use H2O to balance those constituents out
- Sun Feb 21, 2021 11:58 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: H vs q
- Replies: 20
- Views: 967
Re: H vs q
H is at constant pressure so it can be considered as a state function, while q depends on many things and therefore is not a state function
- Sun Feb 21, 2021 11:49 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Exergonic Rxns
- Replies: 14
- Views: 822
Re: Exergonic Rxns
both of these terms pertain to the assumption that delta G is negative, so they can be used interchangeably.
- Sun Feb 21, 2021 11:46 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed system energy change
- Replies: 16
- Views: 883
Re: closed system energy change
work and heat both contribute to energy change, but are not the same thing
- Sun Feb 21, 2021 11:45 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Q and K
- Replies: 40
- Views: 3033
Re: Q and K
Q is when the reaction is not necessarily at equilibrium yet. If Q<K, the reaction favors the products. If Q>K, the reaction favors the reactants. If Q=K then the reaction is at equilibrium
- Sun Feb 21, 2021 11:34 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: interchanging q rev and deltaH
- Replies: 6
- Views: 615
Re: interchanging q rev and deltaH
Isothermal processes and constant pressure are the most common ones that are able to utilize this
- Sun Feb 14, 2021 11:19 pm
- Forum: Calculating Work of Expansion
- Topic: Finding Reversibility
- Replies: 8
- Views: 550
Finding Reversibility
If we are not given an explicit statement that a reaction is irreversible/reversible, what are some ways we could find out?
- Sun Feb 14, 2021 11:10 pm
- Forum: Phase Changes & Related Calculations
- Topic: Endothermic v. Exothermic
- Replies: 139
- Views: 18276
Re: Endothermic v. Exothermic
Endothermic and exothermic reactions are always positive and negative delta Hs, respectively. That is because endo/exothermic reactions are basically defined using this metric
- Sun Feb 14, 2021 11:07 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Can heat capacities be negative?
- Replies: 52
- Views: 14416
Re: Can heat capacities be negative?
When q is negative, then the delta T should be negative as well, cancelling out and resulting in a positive C
- Sun Feb 14, 2021 11:01 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Including n
- Replies: 11
- Views: 580
Re: Including n
Mostly you would play it by what the question is asking for for the final choice and see if you need to solve for n based on information given
- Sun Feb 14, 2021 10:59 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Property
- Replies: 71
- Views: 3574
Re: State Property
With state properties the only thing that matters is the final and initial states, because the intermediate process can only happen one way.
- Sun Feb 07, 2021 11:16 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Total Pressure
- Replies: 6
- Views: 437
Re: Total Pressure
I recall in the question, the gases were on both sides, so it made it easier to solve for the answer using the Kp equation.
- Sun Feb 07, 2021 11:11 pm
- Forum: Calculating Work of Expansion
- Topic: The Sign of Work
- Replies: 7
- Views: 370
Re: The Sign of Work
Work should be negative when it is being done BY the system, and positive it is being done ON the system.
- Sun Feb 07, 2021 11:10 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Does phase matter in Hess's Law?
- Replies: 21
- Views: 2150
Re: Does phase matter in Hess's Law?
For Hess's Law, it is useful to think of the same elements that have different phases as completely different elements when you add and manipulate equations
- Sun Feb 07, 2021 11:09 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Bomb calorimeter
- Replies: 7
- Views: 573
Re: Bomb calorimeter
Using a container that has constant volume in surroundings the heat change of a system is measured using water as its surroundings. It's called a bomb calorimeter because the constant volume is sometimes not enough to hold the pressure change of the reaction, making it explode
- Sun Feb 07, 2021 11:07 pm
- Forum: Phase Changes & Related Calculations
- Topic: Knowing reversible and irreversible
- Replies: 9
- Views: 451
Re: Knowing reversible and irreversible
the reversibility of a reaction should be either explicitly stated in the question or if the pressure stays constant, then the reaction is irreversible
- Sun Jan 31, 2021 10:31 pm
- Forum: Ideal Gases
- Topic: Conditions
- Replies: 20
- Views: 1623
Re: Conditions
273.15 K is equal to 0 Celsius, so the standard is 273.15 K and 1 atm
- Sun Jan 31, 2021 10:27 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Pressure affects only gas reactions?
- Replies: 23
- Views: 1948
Re: Pressure affects only gas reactions?
Only gases can be compressed, so you only count the gaseous state of the element in question.
- Sun Jan 31, 2021 10:17 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: steam causing burns
- Replies: 40
- Views: 1530
Re: steam causing burns
When steam condenses into liquid form, it releases a lot of heat and burns your skin when the reaction proceeds fully
- Sun Jan 31, 2021 10:11 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Diatomic molecules standard enthalpy of formation
- Replies: 22
- Views: 1407
Re: Diatomic molecules standard enthalpy of formation
Diatomic at their standard states are always going to have 0 enthalpy of formation, because that's the only way they can exist naturally, since they can't exist as only single atoms
- Sun Jan 31, 2021 9:59 pm
- Forum: Phase Changes & Related Calculations
- Topic: State Property
- Replies: 11
- Views: 570
Re: State Property
The path taken by heat can vary with changes in properties such as pressure, making it different from a state function which only takes into account the difference between initial and final
- Sun Jan 24, 2021 10:11 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increase in Pressure
- Replies: 31
- Views: 909
Re: Increase in Pressure
You would only count gases, and there should not be any questions with this in it if it has other things that are not gases
- Sun Jan 24, 2021 10:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Strong Acids/Bases
- Replies: 12
- Views: 643
Re: Strong Acids/Bases
At least for the strong bases side, the easiest way to remember them would be just the entire alkali/ne part of the periodic table
- Sun Jan 24, 2021 10:09 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Number 5
- Replies: 18
- Views: 737
Re: Sapling Number 5
This question was pretty confusing to me as well, but as stated above, adding [BH+] to [B] should net you the right answer
- Sun Jan 24, 2021 10:08 pm
- Forum: Ideal Gases
- Topic: pv=nRT
- Replies: 16
- Views: 671
Re: pv=nRT
This equation for this midterm would mainly be used p = (n/v)RT, where (n/v) would denote the concentration of the variable in question in M
- Sun Jan 24, 2021 10:06 pm
- Forum: Ideal Gases
- Topic: Kp?
- Replies: 30
- Views: 1144
Re: Kp?
Kp is solved the same way as Kc is, except for partial pressures in place of concentrations
- Sun Jan 17, 2021 10:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: ICE table troubles
- Replies: 16
- Views: 831
Re: ICE table troubles
In one of the lectures, Lavelle gave us a list of things to keep in mind when going into a problem like the ICE table ones, and it included tips like finding what you know, what you don't know, etc. and I think that it's helpful to go through a mental inventory of these things before filling out you...
- Sun Jan 17, 2021 10:23 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Total Pressure
- Replies: 26
- Views: 2171
Re: Total Pressure
Total pressure is all of the PARTIAL pressures added together, which can usually be solved using Kp and the rest of the given partial pressures
- Sun Jan 17, 2021 10:21 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Week 1 #10
- Replies: 8
- Views: 490
Re: Sapling Week 1 #10
the products over reactants should equal the Kc you need to find for the question
- Sun Jan 17, 2021 10:20 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling #10
- Replies: 4
- Views: 333
Re: Sapling #10
One thing that tripped me up when I tried to solve this question was how I had to add x to the initial concentrations in order to get the answer that you plug into the program. Hope this helps!
- Sun Jan 17, 2021 10:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Total pressure calculation
- Replies: 8
- Views: 1253
Re: Total pressure calculation
When solving with Kp, you can set up your ICE table to solve with the equation you use to solve for concentrations to solve for individual partial pressures. From there you can find all of them and add them together for total pressure.
- Sun Jan 10, 2021 6:06 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling hw 5
- Replies: 14
- Views: 582
Re: Sapling hw 5
For this question I chose the first equation and multiplied K by 3, and took the inverse of the 3rd K, but it still comes up as wrong. Is there a problem with how I calculated it or is there a problem with the question?
- Sun Jan 10, 2021 6:05 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling hw 5
- Replies: 14
- Views: 582
Re: Sapling hw 5
AlyssaMaynard1C wrote:Is the week 1 homework due tonight or next sunday, I'm slightly confused.
The homework is due on the 17th, hope this helps!
- Sun Jan 10, 2021 6:01 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs Kc
- Replies: 9
- Views: 483
Re: K vs Kc
Kc is just K that uses the concentrations of the variables involved. Hope this helps!
- Sun Jan 10, 2021 6:01 pm
- Forum: Ideal Gases
- Topic: Difference between real and ideal gas
- Replies: 10
- Views: 1206
Re: Difference between real and ideal gas
As a follow-up question, if real and ideal gasses are so different than each other, why is it helpful to treat real gasses the same as ideal gasses? Would this assumption not cause problems? I have the same question, because wouldn't the violations of the ideal gas law that the real gas law present...
- Sun Jan 10, 2021 5:58 pm
- Forum: Ideal Gases
- Topic: Kc vs Kp
- Replies: 109
- Views: 5601
Re: Kc vs Kp
You would use Kc if the moles are given, and if the partial pressures are given, use Kp. If both are given then you would have to use the Ideal Gas Law along with given information to convert between the two. Hope this helps!
- Wed Dec 16, 2020 12:55 am
- Forum: SI Units, Unit Conversions
- Topic: Avogadro's Number
- Replies: 12
- Views: 2334
Re: Avogadro's Number
In a more general sense, Avogadro's number is just the amount of objects in one mole. So if you were to set up a dimensional analysis table to solve a question, you should be using Avogadro's number as (6.0221*10^23)objects/mole
- Wed Dec 16, 2020 12:46 am
- Forum: Student Social/Study Group
- Topic: Changing Study Habits
- Replies: 35
- Views: 1706
Re: Changing Study Habits
I think that UA/TA step ups and workshops are what made my final experience bearable in this class. These people are seriously so knowledgeable and so helpful. I'm going to at least one every week starting in 14B!
- Wed Dec 16, 2020 12:30 am
- Forum: Student Social/Study Group
- Topic: Final Exam
- Replies: 49
- Views: 3090
Re: Final Exam
I had enough time, but only because I rushed the questions and probably got a lot more wrong than is good for me
- Wed Dec 16, 2020 12:13 am
- Forum: Student Social/Study Group
- Topic: Plans for Relaxing After Finals
- Replies: 98
- Views: 21652
Re: Plans for Relaxing After Finals
Probably trying to fix the "sleep schedule" that I currently am running
- Wed Dec 16, 2020 12:10 am
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Finding PH and POH
- Replies: 6
- Views: 475
Re: Finding PH and POH
The [OH-] is actually the concentration of OH- ions in the solution, and the pOH is the indication of the "power" of the hydroxide ions, so the number for pOH will be the negative log of [OH]-, which means it will be bigger
- Tue Dec 15, 2020 11:31 pm
- Forum: Empirical & Molecular Formulas
- Topic: Empirical Formulas
- Replies: 4
- Views: 1167
Re: Empirical Formulas
In order to find the empirical formula given the molecular formula, the best way is to divide each number of atoms by the greatest common denominator. Ex. C3H6O3 becomes CH2O
Re: Sapling 1
The ligand's "other name" will take priority in ordering the compounds in alphabetical order. Hope this helps!
Re: Ferrate
These elements are just differently named due to the original Roman name. Elements like Lead are instead Plumbum, and Tin Stannum. Hope this helps!
- Sun Dec 06, 2020 6:49 pm
- Forum: Naming
- Topic: Naming Coordination Compounds
- Replies: 5
- Views: 288
Re: Naming Coordination Compounds
As said above, I think the best way is to partition the ligands, transition metal, then the anion afterwards, and then arrange/add the extra parts afterwards.
Re: -ate
Only use -ate for negative charge, and neutral/positive compounds will just end in the name of the last part
- Sun Dec 06, 2020 6:43 pm
- Forum: Naming
- Topic: Naming [Co(CN)5(OH2)]2-
- Replies: 5
- Views: 520
Re: Naming [Co(CN)5(OH2)]2-
I think this is still aqua and not hydroxo, since the OH2 would signify water just in a different order. Hope this helps!
- Sun Nov 29, 2020 11:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Shape Names
- Replies: 50
- Views: 2711
Re: Shape Names
2 lp and 2 bonds is bent, as well as 2 lp and 1 lp. Hope this helps!
- Sun Nov 29, 2020 11:01 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Equatorial and Axial
- Replies: 2
- Views: 119
Re: Equatorial and Axial
I think the general rule is that there is less crowding in equatorial bonds rather than axial ones, so atoms will tend towards equatorial first, but I'm not sure and he will probably cover it in lecture at some point. Hope this helps!
- Sun Nov 29, 2020 10:58 pm
- Forum: Hybridization
- Topic: Sapling #12
- Replies: 29
- Views: 1204
Re: Sapling #12
to find the hybridization for the oxygen, you have to count the bonded ATOMS (not just bonds!) and the lone pairs as well, so it would come out to 2 atoms and 2 lone pairs, which is an sp3 orbital
- Sun Nov 29, 2020 10:55 pm
- Forum: Hybridization
- Topic: Sapling #11
- Replies: 19
- Views: 977
Re: Sapling #11
This example specifies hybridization for the Phosphorus atoms, so you would count the three bonded atoms, the three O atoms, and then the lone pair, and that would lead to 4 groups, which means it's an sp3 orbital
- Sun Nov 29, 2020 10:52 pm
- Forum: Hybridization
- Topic: Single Bonds and Sigma Bonds
- Replies: 23
- Views: 1229
Re: Single Bonds and Sigma Bonds
Single bonds are only composed of Sigma bonds, however they also exist in double and triple bonds
- Tue Nov 24, 2020 9:54 pm
- Forum: Octet Exceptions
- Topic: Phosphate
- Replies: 7
- Views: 514
Re: Phosphate
Phosphate is in the 3p orbital, so it has access to the 3d orbital of electrons, so it can fill that shell to compensate.
- Tue Nov 24, 2020 9:49 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: oxidation numbers and resonance
- Replies: 3
- Views: 194
Re: oxidation numbers and resonance
Oxidation numbers are hypothetical values, so using formal charge for specific resonance structures is probably better.
- Tue Nov 24, 2020 9:33 pm
- Forum: Electronegativity
- Topic: How to memorize
- Replies: 6
- Views: 383
Re: How to memorize
A general rule to also remember could be that going down the table decreases more than going towards the left. Hope this helps!
- Tue Nov 24, 2020 9:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: Stronger Melting Point
- Replies: 11
- Views: 643
Re: Stronger Melting Point
Ionic bonds are the highest energy bonds that we know of in this class up until now, so it would have a higher melting point.
- Tue Nov 24, 2020 9:27 pm
- Forum: Ionic & Covalent Bonds
- Topic: Textbook Question 1A.13
- Replies: 4
- Views: 410
Re: Textbook Question 1A.13
The parentheses on the NH2 denote that the 2 hydrogens are only bonded to the N, which is bonded to the first C, which is denoted by how COOH is after the NH2
- Sun Nov 15, 2020 5:58 pm
- Forum: Octet Exceptions
- Topic: Octet Rule Exceptions
- Replies: 20
- Views: 1505
Re: Octet Rule Exceptions
If somebody could help me make a list of all of the exceptions for this midterm, that would help a lot. Right now I have the first four elements, elements past period 3 can exceed, and group 13 only need 6. Thanks!
- Sun Nov 15, 2020 5:31 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic vs Atomic Radius
- Replies: 7
- Views: 503
Re: Ionic vs Atomic Radius
AlyssaMaynard1C wrote:Will we be able to look at a chart on the midterm for the electronegativity and other descriptions?
I'm pretty sure electronegativity will be given but all the other trends are probably just comparisons
- Sun Nov 15, 2020 5:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: Electronegativity
- Replies: 18
- Views: 775
Re: Electronegativity
I would suggest learning and memorizing the trends given, and also the fact that electronegativity differences between 0.4 and 1.7 are polar bonds. They should be given on the test. Hope this helps!
- Sun Nov 15, 2020 5:26 pm
- Forum: Ionic & Covalent Bonds
- Topic: Sulfate
- Replies: 8
- Views: 257
Re: Sulfate
Any element past the 3rd period of the periodic table is able to have an expanded octet of electrons due to having access to more values of l.
- Sun Nov 15, 2020 5:21 pm
- Forum: Ionic & Covalent Bonds
- Topic: What do delta positive and delta negative refer to?
- Replies: 3
- Views: 1827
Re: What do delta positive and delta negative refer to?
The negative sign in this unit usually means the subject has an attractive force. This would mean that the part of the atom that has the highest electronegativity would have a delta negative. Hope this helped!
- Sun Nov 08, 2020 10:16 pm
- Forum: Electronegativity
- Topic: Noble Gases
- Replies: 40
- Views: 12905
Re: Noble Gases
Noble Gases are exceptions from the rules because they are out of the running so to speak for gaining/losing electrons
- Sun Nov 08, 2020 10:15 pm
- Forum: Ionic & Covalent Bonds
- Topic: Electron Affinity
- Replies: 8
- Views: 436
Re: Electron Affinity
Electron affinity measures how inclined an atom is to take on another electron
- Sun Nov 08, 2020 10:14 pm
- Forum: Ionic & Covalent Bonds
- Topic: Atomic Radius
- Replies: 38
- Views: 3312
Re: Atomic Radius
More protons equals more positive charge to attract electrons
- Sun Nov 08, 2020 10:13 pm
- Forum: Ionic & Covalent Bonds
- Topic: Sapling Question #3
- Replies: 6
- Views: 409
Re: Sapling Question #3
Any element past period 3 of the periodic table can form more bonds than accounted for by the octet rule as dictated by its d orbital having the capacity to take in more electrons
- Sun Nov 08, 2020 10:12 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal charges and stability
- Replies: 5
- Views: 352
Re: Formal charges and stability
I think any charge that sums up to +2 should be counted the same in any configuration just based on the fact that it has charge as opposed to being neutral.
- Sun Nov 01, 2020 6:22 pm
- Forum: Properties of Light
- Topic: Do we need to know the ranges of waves on the electromagnetic spectrum?
- Replies: 7
- Views: 282
Re: Do we need to know the ranges of waves on the electromagnetic spectrum?
I think we only need to know ranges for prominent ones like visible and UV. Hope this helps!
- Sun Nov 01, 2020 6:08 pm
- Forum: Photoelectric Effect
- Topic: Lyman Series
- Replies: 30
- Views: 1363
Re: Lyman Series
Adding on to other answers, the Balmer series would be n=2 and the Paschen series would be n=3. Hope this helps!
- Sun Nov 01, 2020 6:01 pm
- Forum: Properties of Light
- Topic: spectral lines
- Replies: 6
- Views: 340
Re: spectral lines
It would depend on the direction relative to which the electron moved up and down the energy levels.
- Sun Nov 01, 2020 5:39 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Week 2,3,4 Sapling HW
- Replies: 5
- Views: 422
Re: Week 2,3,4 Sapling HW
I haven't seen chem community in a while, sorry about that! To answer your question if you still need it, I used a different variable of the Rydberg equation that uses a different R constant. So if you wanted to do the question using the equation that he gives us you would have to find out the frequ...
- Sun Nov 01, 2020 5:32 pm
- Forum: Ionic & Covalent Bonds
- Topic: hydrogen
- Replies: 19
- Views: 1021
Re: hydrogen
Hydrogen bonds are only able to be established on those 3 elements due to how electronegative they are relative to Hydrogen
- Sun Oct 25, 2020 6:17 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation and Negative Signs
- Replies: 11
- Views: 1880
Re: Rydberg Equation and Negative Signs
Usually, the question will ask for something related to the magnitude of energy that was released. However, when you use the Rydberg Constant, you will usually be solving for the energy released by one single electron, so relatively, the energy will be negative. Hope this helps!
- Sun Oct 25, 2020 6:15 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: When n= infinity, the energy required = 0
- Replies: 4
- Views: 665
Re: When n= infinity, the energy required = 0
Because when the denominator is infinity, the entire fraction equates to zero, since it is an infinitesimally small fraction. Hope this helps!
- Sun Oct 25, 2020 6:14 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectra Post Module Assessment #28
- Replies: 1
- Views: 157
Re: Atomic Spectra Post Module Assessment #28
It would be D. The question states that there are 1,650,763.73 wavelengths in one meter, so in order to find the length of one wavelength, you have to divide 1 meter by 1,650,763.73, in order to get the wavelength, 6.058*10^-7. From there you can use E=h(c/wavelength) in order to find the energy req...
- Sun Oct 25, 2020 6:10 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Electrostatic potential energy
- Replies: 2
- Views: 99
Re: Electrostatic potential energy
Whereas electrostatic potential energy is the energy between two charges, quantized energy of an electron is only exclusively dealing with one electron. Hope this helps!
- Sun Oct 25, 2020 6:07 pm
- Forum: Properties of Light
- Topic: Balmer or Lyman Series
- Replies: 9
- Views: 356
Re: Balmer or Lyman Series
Rather than the starting point, the Balmer and Lyman series denote the endings of an energy change. The Balmer series consists of visible light, ending in n=2, and the Lyman series consists of UV light, ending in n=1. Each lower energy level (Ex. n=2 to n=1 as opposed to n=3 to n=2), has a higher en...
- Sun Oct 25, 2020 6:04 pm
- Forum: SI Units, Unit Conversions
- Topic: Can someone explain Avogrado's #?
- Replies: 8
- Views: 984
Re: Can someone explain Avogrado's #?
Avogadro's number is just the amount of OBJECTS in a mole of x. So if I were to say that there is 1 mol of carrots in Billy's garden, then there'd be 6.0221*10^23 carrots in his garden. Hope this helps!
- Sun Oct 18, 2020 4:02 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg's Constant
- Replies: 2
- Views: 67
Re: Rydberg's Constant
Thanks for the clear explanation, I understand now!
- Sun Oct 18, 2020 3:46 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg's Constant
- Replies: 2
- Views: 67
Rydberg's Constant
On Dr. Lavelle's lectures, he uses 3.29*10^15, but when I use it in the Rydberg equation it's 1.07*10^7, could anyone explain the difference to me? Thanks!
- Sun Oct 18, 2020 3:45 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Week 2,3,4 Sapling HW
- Replies: 5
- Views: 422
Re: Week 2,3,4 Sapling HW
For this question, you first have to look at the given wavelength, which is 6.563 *10^-7 m (converted from nanometers). Matching this with the numbers given on the EM spectrum tells us that this light is on the wavelength of visible light, which fits in the Balmer series, which means that the light ...
- Sat Oct 17, 2020 6:38 pm
- Forum: Properties of Electrons
- Topic: Bound electron v. Free electron
- Replies: 5
- Views: 266
Re: Bound electron v. Free electron
I like to think of it this way: the electrons at lower energy levels have lower energy because they're essentially being held still due to being closer to the nucleus. Hope this helps!
- Wed Oct 07, 2020 5:57 pm
- Forum: Significant Figures
- Topic: Sig Fig usage on exams
- Replies: 11
- Views: 415
Re: Sig Fig usage on exams
As people have stated above, I use the sig figs presented in the problem and only round at the end. If there are multiple numbers with different amounts of sig figs in the problem, then I just round to 4 decimal points. Hopefully Dr. Lavelle will mention this in lecture soon.
- Wed Oct 07, 2020 5:48 pm
- Forum: Balancing Chemical Reactions
- Topic: Fractions
- Replies: 34
- Views: 1499
Re: Fractions
I think in one of the modules Prof. Lavelle specifically states that you need to simplify out fraction stoichiometric ratios. Hope this helps!
- Wed Oct 07, 2020 5:44 pm
- Forum: SI Units, Unit Conversions
- Topic: Formula Units
- Replies: 8
- Views: 304
Re: Formula Units
The textbook states that Avogadro's CONSTANT is a pure number with no units, while Avogadro's NUMBER can have any unit pertaining to objects. Hope this helps!
- Wed Oct 07, 2020 5:41 pm
- Forum: Empirical & Molecular Formulas
- Topic: Outline 1 Question L39
- Replies: 3
- Views: 197
Re: Outline 1 Question L39
Given: 1.5g Sn 26.45g Crucible Mass 28.35g Mass of Crucible + Product From here, you can calculate the mass of Oxygen, 28.35g (total) - 26.45g (crucible) = 1.9g product 1.9g product - 1.5g Sn = .4g O Use this .4g O in order to find out the moles of O .4g O/16.11g O/mol = .025 Use given 1.5g Sn in or...