Search found 98 matches
- Sun Mar 08, 2020 8:31 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Problems
- Replies: 6
- Views: 456
Re: Problems
In reference to what?
- Sun Mar 08, 2020 8:31 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Cell Diagram
- Replies: 21
- Views: 1065
Re: Cell Diagram
Yea I think that is an assumption that we make, but they will usually specify regardless.
- Sun Mar 08, 2020 8:30 pm
- Forum: General Rate Laws
- Topic: Pseudo-Rate Law
- Replies: 2
- Views: 184
Re: Pseudo-Rate Law
You essentially assume that all the other reactions happen significantly faster than all of the other reactions, so there is a buildup of product of the reaction before and reactant after, as that single slow step is what limits the entire overall reaction.
- Sun Mar 08, 2020 8:29 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Rate of Formation/Rate Law
- Replies: 1
- Views: 111
Re: Rate of Formation/Rate Law
The rate law can be used to show the rate of a reaction, which is the rate of formation of the product.
- Sun Mar 08, 2020 8:16 pm
- Forum: General Rate Laws
- Topic: rate consumption
- Replies: 1
- Views: 148
Re: rate consumption
It depends on the order of the reaction, but you can look at the formula sheet and plug in the values you know.
- Sun Mar 08, 2020 8:14 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Determination
- Replies: 1
- Views: 142
Re: Determination
Essentially, you follow the equations on the formula sheet, plugging in the values that you know and use a system of equations to calculate the final missing value.
- Sun Mar 08, 2020 8:13 pm
- Forum: General Rate Laws
- Topic: integrated rate law vs general
- Replies: 8
- Views: 694
Re: integrated rate law vs general
The integrated rate law is the result of integrating the general rate law, to give you the exact concentration of a reactant at a certain time.
- Sun Mar 08, 2020 8:12 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs free energy and K
- Replies: 3
- Views: 231
Re: Gibbs free energy and K
The equations are on the formula sheet, but delta G = RTlnK, and u can extrapolate that out to non-standard values of delta G, which shows how Q is related as well.
- Sun Mar 08, 2020 8:11 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: calculating Q
- Replies: 12
- Views: 693
Re: calculating Q
It can be determined by the overall cell reaction, with the concentrations plugged in for Q (products over reactants)
- Thu Mar 05, 2020 6:42 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Question 6.65
- Replies: 2
- Views: 250
Question 6.65
What range (in volts) does a voltmeter need to have to measure pH in the range of 1 to 14 at 25 8C if the voltage is zero when pH = 7?
If I use the lower concentration value at 10^-7, I keep getting half the value of the answer in the answer booklet.
If I use the lower concentration value at 10^-7, I keep getting half the value of the answer in the answer booklet.
- Mon Feb 24, 2020 4:58 pm
- Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
- Topic: Rechargeable Batteries
- Replies: 4
- Views: 348
Rechargeable Batteries
Do we have to know how a rechargeable battery works? Because I think Lavelle said that we did not need to know how it works in class.
- Mon Feb 24, 2020 4:56 pm
- Forum: Balancing Redox Reactions
- Topic: Platinum in cell diagram
- Replies: 10
- Views: 687
Re: Platinum in cell diagram
You always need something solid that can act as the actual electrode, so you would use a metal like Pt as that electrode.
- Mon Feb 24, 2020 4:55 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: pH meter example
- Replies: 1
- Views: 135
pH meter example
For the pH meter example he did, is the pH meter the cathode or the anode?
- Mon Feb 24, 2020 4:53 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridge
- Replies: 6
- Views: 381
Salt Bridge
Can a salt bridge consist of any salt or does it have to have to include some of the material in either the cathode or anode solution?
- Mon Feb 24, 2020 4:52 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Concentration Cells
- Replies: 5
- Views: 343
Concentration Cells
Can you use a salt bridge for a concentration cell or do you need a permeable membrane?
- Mon Feb 24, 2020 4:50 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Pressure
- Replies: 2
- Views: 231
Pressure
Why does pressure matter for an electrolytic cell? Since they are all concentrations or solids, why would it matter what the pressure is?
- Mon Feb 24, 2020 4:49 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Electrolytic Cells
- Replies: 3
- Views: 282
Electrolytic Cells
How can you control which way the voltage flows in an electrolytic cell? like why would it just not go in reverse?
- Mon Feb 24, 2020 4:47 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst
- Replies: 7
- Views: 475
Re: Nernst
If you figure out the reduction equation and the oxidation reaction, and when you cancel them out you will see the exact number of electrons being transferred, which will be your n.
- Mon Feb 24, 2020 4:46 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Positive and negative standard potential
- Replies: 3
- Views: 151
Re: Positive and negative standard potential
The more positive reduction potential makes it easier to oxidize hydrogen, which means that it will be harder to reduce hydrogen.
- Mon Feb 24, 2020 4:45 pm
- Forum: Administrative Questions and Class Announcements
- Topic: midterm solutions
- Replies: 4
- Views: 282
Re: midterm solutions
Everything is posted on the website basically.
- Mon Feb 24, 2020 4:44 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Vant Hoff Equation
- Replies: 9
- Views: 650
Re: Vant Hoff Equation
All of these equations are basically derived from the ones given on the formula sheet, it just depends on which values are constant and which ones you can manipulate.
- Mon Feb 24, 2020 4:43 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Difference
- Replies: 5
- Views: 313
Re: Difference
Also, Delta G cannot be calculated by itself, its a derived value basically.
- Mon Feb 24, 2020 4:42 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Maximum Potential and Voltage
- Replies: 6
- Views: 409
Re: Maximum Potential and Voltage
We are essentially trying to find the maximum potential of the cell, which is when there is no current flowing between the two electrodes. When the electrons start to flow, that is the voltage, which decreases over time.
- Mon Feb 24, 2020 4:41 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n
- Replies: 13
- Views: 687
Re: n
the R is 8.314, as that is the R that uses Joules, which is the unit we need to get into Volts
- Mon Feb 24, 2020 4:40 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: test 2 material clarification
- Replies: 10
- Views: 606
Re: test 2 material clarification
Test 2 is the last page of thermodynamics and the entirety of electrochem. The only material left that we have to be tested on is kinetics.
- Mon Feb 24, 2020 4:38 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Electrolytic Cell
- Replies: 2
- Views: 236
Re: Electrolytic Cell
Essentially it works like a galvanic cell in which there are both a cathode and an anode, but unlike a galvanic cell, the base reaction has a negative E, and voltage is supplied to keep the reaction progressing.
- Mon Feb 03, 2020 2:27 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: endo vs exo
- Replies: 8
- Views: 161
Re: endo vs exo
Breaking a bond requires energy, so it would be endothermic while forming bonds releases energy (exothermic)
- Mon Feb 03, 2020 2:26 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: reversing signs
- Replies: 5
- Views: 237
Re: reversing signs
You only need to reverse the sign for the delta H if you are measuring the change in enthalpy in the surroundings, so the actual system will be the opposite of that.
- Mon Feb 03, 2020 2:20 pm
- Forum: Calculating Work of Expansion
- Topic: units
- Replies: 9
- Views: 170
Re: units
w is given in joules.
- Mon Feb 03, 2020 2:19 pm
- 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: Midterm Review
- Replies: 7
- Views: 358
Re: Midterm Review
I don't think he has released his review sheet yet, hopefully he will post it later as we get closer to the midterm.
- Mon Feb 03, 2020 2:18 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: examples of doing work
- Replies: 2
- Views: 131
Re: examples of doing work
Most of the examples of work we will be covering will be a change in volume, like the piston example discussed in class, where the gas inside pushes the piston out(work done by the system) or when the gas is compressed by the piston (work done to the system).
- Mon Feb 03, 2020 2:16 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: question on lecture notes about closed system
- Replies: 5
- Views: 180
Re: question on lecture notes about closed system
If there was insulation, then it would be an isolated system, as there would be no change in matter or heat.
- Mon Feb 03, 2020 2:14 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: closed system energy change
- Replies: 16
- Views: 706
Re: closed system energy change
No, in a closed system, heat and work are two different aspects of energy change.
- Thu Jan 23, 2020 5:54 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Partial Pressure vs Pressure
- Replies: 7
- Views: 208
Re: Partial Pressure vs Pressure
Partial Pressure more specifically is talking about the pressure one gas exerts, while pressure talks about the overall pressure exerted by all the gases in the container, So the partial pressure of all the gases in a container can be added to find the overall pressure.
- Thu Jan 23, 2020 5:53 pm
- Forum: Student Social/Study Group
- Topic: Midterm and Final Question
- Replies: 18
- Views: 993
Re: Midterm and Final Question
Last quarter there were a bunch of prep material that TAs and UAs gave out, along with past year exams, but Lavelle doesnt give anything himself.
- Thu Jan 23, 2020 5:52 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: 5.61f
- Replies: 5
- Views: 177
Re: 5.61f
No the H2O would still not affect anything, as it is the solvent, so there is so much of it that the concentration of it wont really change when the reaction occurs, because it is in so much excess.
- Thu Jan 23, 2020 5:50 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: sig figs
- Replies: 2
- Views: 70
Re: sig figs
It depends, because if the K is given as a constant, then you do not include it when counting sig figs, but if you are calculating the K, then you will have to use its sig figs
- Thu Jan 23, 2020 5:48 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Buffers
- Replies: 2
- Views: 70
Re: Buffers
It all depends on what is present when you measure the pH, as a buffer will have concentrations of an acid and a base, rather than just the acid or just the base.
- Thu Jan 23, 2020 5:47 pm
- Forum: Phase Changes & Related Calculations
- Topic: Enthalpy Units
- Replies: 3
- Views: 159
Re: Enthalpy Units
Usually, enthalpy is given in Joules, but other units can be calories, kJ, kilocalories...
- Thu Jan 23, 2020 5:45 pm
- Forum: Ideal Gases
- Topic: Pressure
- Replies: 2
- Views: 132
Re: Pressure
Adding the inert gas will not change the pressure of the actual gases in the reaction, as that gas will be present in both the reactants and products, as it is inert. As a result, adding an inert gas does not change the pressure for the actual gases, so there is no shift in the equilibrium.
- Thu Jan 23, 2020 5:43 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Temperature
- Replies: 6
- Views: 187
Re: Temperature
For exothermic reaction, increasing the temperature will decrease the K, while for endothermic, increasing the temperature will increase the k
- Sat Jan 18, 2020 2:33 pm
- Forum: General Science Questions
- Topic: Body Reactions
- Replies: 1
- Views: 105
Re: Body Reactions
There will be a different equilibrium constant values for the reactions, but all of it will be relative anyways.
- Sat Jan 18, 2020 2:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Solubility
- Replies: 2
- Views: 83
Re: Solubility
Equilibrium constants just describe how the reaction will be at equilibrium (the relative concentrations of the products and reactants), so you can use it to predict the behavior of any reaction.
- Wed Jan 15, 2020 5:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: When to use K and Kp
- Replies: 12
- Views: 355
When to use K and Kp
When you are given a random chemical equation, does it matter if you use K or Kp (concentration or pressure) if the question doesn't specifically state what it wants?
- Wed Jan 15, 2020 5:35 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K cutoff
- Replies: 5
- Views: 183
Re: K cutoff
It can be less than 10^-3 or greater than 10^3
- Wed Jan 15, 2020 5:34 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Why Ignore Liquid or Solid Volume When Calculating K
- Replies: 7
- Views: 211
Re: Why Ignore Liquid or Solid Volume When Calculating K
K is all about the concentrations, and the change in the liquid and solid-state is negligible so we can just ignore that.
- Wed Jan 15, 2020 5:33 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Endothermic and exothermic reactions
- Replies: 11
- Views: 1020
Re: Endothermic and exothermic reactions
What helps me visualize this is to treat the energy almost like a product or reactant. So if the reaction is exothermic, energy is a "product" and vice versa. If you increase the temp, you would increase the delta H, so whichever side it is on will end up decreasing.
- Wed Jan 15, 2020 5:30 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 6
- Views: 950
Re: Le Chatelier's Principle
When the pressure changes, then the Q will be different than the Kp, so you can figure out which way the experiment will shift according to that.
- Wed Jan 15, 2020 5:29 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: calculating kP
- Replies: 4
- Views: 168
Re: calculating kP
Its honestly all about being consistent, so if you use the same units for every single calculation, you should be fine.
- Wed Jan 15, 2020 5:28 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: volume's effect on K
- Replies: 7
- Views: 167
Re: volume's effect on K
K is a constant, so it will essentially always stay the same, with the single exception being temperature due to the change in the kinetic energy of the gas molecules.
- Wed Jan 15, 2020 5:27 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Compression on Equilibrium
- Replies: 4
- Views: 232
Re: Compression on Equilibrium
There would be no shift in the equilibrium, as if you calculate the new pressure/concentration of the gases after the compression, they will balance out in the K equation, so it would not matter.
- Sun Dec 01, 2019 11:43 pm
- Forum: Naming
- Topic: Bis, Tris, Tetrakis, Pentakis
- Replies: 3
- Views: 424
Re: Bis, Tris, Tetrakis, Pentakis
You use these when there is a prefix for the logans, so u use bis instead of having bi in the name of the coordination compound and the ligand itself - bis instead of bi bi(ligand)
- Sun Dec 01, 2019 11:41 pm
- Forum: Hybridization
- Topic: Electronegativity
- Replies: 4
- Views: 254
Re: Electronegativity
Hybridization is the orbitals combining, I don’t think it’s really related to the electro negativity.
- Sun Dec 01, 2019 11:40 pm
- Forum: Properties & Structures of Inorganic & Organic Bases
- Topic: strong and weak acid and bases
- Replies: 2
- Views: 171
Re: strong and weak acid and bases
I think we have to know them by the general trends, like the alkali metals make strong bases.
- Sun Dec 01, 2019 11:39 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Breaking of pi and sigma bonds
- Replies: 4
- Views: 346
Re: Breaking of pi and sigma bonds
Sigma bonds will not break if the atoms rotate, only pi bonds will.
- Sun Dec 01, 2019 11:38 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: electronegativity
- Replies: 4
- Views: 139
Re: electronegativity
The greater the difference in the electro negativity between the two atoms is generally the way to determine which is more electronegative.
- Sun Nov 24, 2019 10:21 pm
- Forum: Hybridization
- Topic: Identifying hybridizations
- Replies: 2
- Views: 108
Re: Identifying hybridizations
The easiest way for me to memorize hybridization is to simply count the number of bonds. From there you can fill out the orbitals, with s being one bond, sp going from 2 bonds to 4 with sp3, continuing on with d.
- Sun Nov 24, 2019 10:20 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar vs. Nonpolar
- Replies: 3
- Views: 190
Re: Polar vs. Nonpolar
The reason that molecule is polar is that the shape is tetrahedral, which means the two Cl atoms aren't going to be opposite of each other. Since they aren't opposites of each other, they will not cancel out and as a result, the molecule will have a net dipole
Re: Naming
He sent out an email with all of the ligand names and stuff that you need to memorize for the final.
- Sun Nov 24, 2019 10:17 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond angles
- Replies: 7
- Views: 402
Re: Bond angles
The bond angles are less than 120 and 90, as it would be a trigonal bipyramidal without the "top" electron, so the lone pair repulsion pushes down and makes the angles slightly less than they were originally with the trigonal bipyramidal shape.
- Sun Nov 24, 2019 10:15 pm
- Forum: Naming
- Topic: Di-, Tri-, Tetra- vs Bis-, Tris-, Tetrakis-
- Replies: 11
- Views: 893
Re: Di-, Tri-, Tetra- vs Bis-, Tris-, Tetrakis-
They are used when the ligand has a prefix itself, so the ligand would have a di, tri, etc, so instead of saying didi, you would just say dis.
- Sun Nov 17, 2019 3:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: writing VSPER formulas
- Replies: 2
- Views: 136
Re: writing VSPER formulas
If you draw out I^3-, the central I atom ends up having 5 bonding regions, with 2 bonds and 3 lone pairs. If you look on the VSEPR chart, that would give u a formula of AX2E3, which gives u the linear shape with 180-degree bond angles
- Sun Nov 17, 2019 2:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Different type of Molecular Shapes
- Replies: 2
- Views: 160
Re: Different type of Molecular Shapes
Linear is any situation in which there are simply two atoms bonded to each other (because it resembles a "line"). Trigonal planar is when the central atom has 5 bonding regions, with 3 bonds and 2 lone pairs. Bent is when the central atom has 4 bonding regions, with 2 bonds and 2 lone pairs.
- Sun Nov 17, 2019 2:50 pm
- Forum: Hybridization
- Topic: Homework Outline for Test
- Replies: 5
- Views: 253
Re: Homework Outline for Test
I think the majority of the test will be material from the molecular shape and structure homework.
- Sun Nov 17, 2019 2:46 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: VSEPR angles
- Replies: 4
- Views: 232
Re: VSEPR angles
Personally, I try to kinda visualize all of the basic shapes (tetrahedral, trigonal pyramidal, trigonal bipyramidal), and in these shapes, all the angles are pretty easy to deduce once you have already kinda visualized the name. The remaining bond angles are usually just less than the "base&quo...
- Sun Nov 17, 2019 2:42 pm
- Forum: Hybridization
- Topic: Test 2 Topics
- Replies: 11
- Views: 639
Re: Test 2 Topics
I think he said it is going to cover bonding, VSEPR, and intermolecular interactions. It is not gonna include any content from the midterm, so basically from Outline 2D and onwards to where we are now basically.
- Sun Nov 10, 2019 11:17 pm
- Forum: Electronegativity
- Topic: Atom size
- Replies: 22
- Views: 3071
Re: Atom size
Its essentially all determined by how close the electrons are to the actual nucleus.
- Sun Nov 10, 2019 11:16 pm
- Forum: Dipole Moments
- Topic: Instantaneous Dipole
- Replies: 2
- Views: 133
Re: Instantaneous Dipole
An instantanous dipole is basically when a nearby atom has a dipole moment which causes another atom to have its charges shift as a result of the other atom.
- Sun Nov 10, 2019 11:14 pm
- Forum: Dipole Moments
- Topic: Shape of Molecule
- Replies: 2
- Views: 193
Re: Shape of Molecule
The shape basically shows the electron density, so there will only be those interactions where there is/isnt an electron.
- Sun Nov 10, 2019 11:13 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Polarizing Calculations
- Replies: 2
- Views: 150
Polarizing Calculations
For the final/upcoming test, will we have to calculate how polarizing an atom is using electronegativity?
- Sun Nov 10, 2019 11:09 pm
- Forum: Octet Exceptions
- Topic: Octet exception
- Replies: 14
- Views: 1168
Re: Octet exception
Elements that have a d-orbital are able to have more than an octet, as the electrons will go into the d-orbital. These are basically all the elements in the 3rd row and down.
- Sun Nov 03, 2019 10:11 pm
- Forum: Einstein Equation
- Topic: 1B.15
- Replies: 3
- Views: 305
Re: 1B.15
You can use the c = lambda nu, and then use E = kv to get the energy.
- Sun Nov 03, 2019 10:10 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent Character
- Replies: 3
- Views: 211
Re: Covalent Character
Covalent character means that the bond is expressing covalent characteristics, which means that the atoms are sharing electrons. The covalent character means that the atoms are sharing the atoms, so they cannot be separated in water and other properties like that. A compound that has a high covalent...
- Sun Nov 03, 2019 10:08 pm
- Forum: Bond Lengths & Energies
- Topic: bond lengths
- Replies: 2
- Views: 138
Re: bond lengths
We just need to know that all the bonds in resonance structures are the same length. I think he said that the rest of the information would not be covered but I am not sure.
- Sun Nov 03, 2019 10:06 pm
- Forum: Lewis Structures
- Topic: Determining Atom Arrangement
- Replies: 1
- Views: 131
Re: Determining Atom Arrangement
Usually, for the larger molecules, there are differences in the way the formula is presented that gives hints, as atoms that are bonded to each other are usually next to each other in the molecular formula.
- Sun Nov 03, 2019 10:04 pm
- Forum: Photoelectric Effect
- Topic: Dino Nuggets Review #8.a)
- Replies: 2
- Views: 164
Re: Dino Nuggets Review #8.a)
Essentially energy is conserved throughout the entire experiment, as the energy of the photon equals the work equation and the energy of the electron ejected. That means that the energy is conserved throughout the reaction. In reference to the conceptual change, photons were no longer only looked as...
- Mon Oct 28, 2019 2:26 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Drawing Orbitals and Electron Spins
- Replies: 2
- Views: 191
Re: Drawing Orbitals and Electron Spins
That kind of detail isnt really necessary, so only draw it out if the question specifically asks for it.
- Mon Oct 28, 2019 2:25 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electrostatic potential energy
- Replies: 1
- Views: 110
Re: Electrostatic potential energy
The charge of an electron is a constant, and the distance between the charges is the same as the radius of the atom.
- Mon Oct 28, 2019 2:24 am
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Atomic Spectroscopy
- Replies: 2
- Views: 112
Re: Atomic Spectroscopy
We have to use the formula for finding the energy of an energy transition (E = Rh/n^2) and E = hv to get the frecuency
- Mon Oct 28, 2019 2:22 am
- Forum: Student Social/Study Group
- Topic: Will different midterm review sessions cover the same material?
- Replies: 8
- Views: 358
Re: Will different midterm review sessions cover the same material?
I am sure that all the review sessions will go over all the proper and necessary material - I doubt you will get punished for having other commitments.
- Mon Oct 28, 2019 2:21 am
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal Charge equation?
- Replies: 5
- Views: 187
Re: Formal Charge equation?
I believe he is referring to the number of bonds that there are (the number of lines drawn on the Lewis structure for that specific atom.
- Sun Oct 20, 2019 10:14 pm
- Forum: Photoelectric Effect
- Topic: Chemistry Equations
- Replies: 2
- Views: 92
Re: Chemistry Equations
All the equations we will need to know will be on the first sheet of any test we take, so we wont have to memorize or keep track of all of them and their constants. You will need to know which variable means what, which will allow you to use the right equation for any set of given information
- Sun Oct 20, 2019 10:12 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Multi-electron atoms
- Replies: 7
- Views: 263
Re: Multi-electron atoms
Yea, multi-electron atom refers to all atoms outside of Hydrogen
- Sun Oct 20, 2019 10:10 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configurations
- Replies: 2
- Views: 168
Re: Electron Configurations
They change with ionic bonding, where the electrons are transferred but not with covalent bonding.
- Sun Oct 20, 2019 10:09 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg
- Replies: 3
- Views: 113
Re: Heisenberg
This basically shows that if an electron was centralized in the nucleus, the level of uncertainty would be so large that it would be basically useless. As a result, the size of an atom must be greater so that the Heisenberg equation was actually applicable.
- Sun Oct 20, 2019 10:07 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Heisenberg
- Replies: 5
- Views: 223
Re: Heisenberg
The Heisenberg principle highlights that the exact position of an electron cannot be found and that there will always be a level of uncertainty. When they used the size of the nucleus of a hydrogen atom to find the level of uncertainty, they got a value that was so large (greater than the speed of l...
- Sun Oct 20, 2019 10:04 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: The equation
- Replies: 2
- Views: 111
Re: The equation
The way to derive the exact equation is really complicated and involves really high-level math, so I do not think you need to know how to derive it, rather just what it's used for and how to use it.
- Sun Oct 13, 2019 11:13 pm
- Forum: Properties of Electrons
- Topic: Energy/Light Levels
- Replies: 2
- Views: 73
Re: Energy/Light Levels
I don't think we need to know the specific n values for specific types of waves. I think we just need to know that as n increases, the overall energy decreases.
- Sun Oct 13, 2019 11:10 pm
- Forum: Properties of Electrons
- Topic: electrons
- Replies: 3
- Views: 103
Re: electrons
Essentially everything has both normal particle properties and wave properties. It's just that the larger particles have such small wavelengths that they are basically not identifiable, which is seen through the de Broglie equation. That's why even a baseball has wave properties, but they are so sma...
- Sun Oct 13, 2019 11:06 pm
- Forum: Properties of Electrons
- Topic: Electrons wavelengths and frequency
- Replies: 2
- Views: 197
Re: Electrons wavelengths and frequency
I am pretty sure everything in the universe has its own energy. An electron can absorb energy from photons, which causes it to jump up electron levels. When the electron loses that energy, it drops down energy levels, releasing the energy it absorbed originally from the photon. It has its own wavele...
- Sun Oct 13, 2019 11:00 pm
- Forum: Properties of Light
- Topic: Physically changing amplitude
- Replies: 1
- Views: 49
Physically changing amplitude
How can we practically manipulate intensity? (like we can change wavelength and frequency by changing the color of the light)
- Sun Oct 13, 2019 10:59 pm
- Forum: Properties of Light
- Topic: Changing Amplitude
- Replies: 2
- Views: 176
Changing Amplitude
We talked in class about how changing the intensity (amplitude) of the light did not change the energy of the photon. However, how does increasing the amplitude result in more total photons?
- Mon Oct 07, 2019 3:13 pm
- Forum: Properties of Electrons
- Topic: Balmer and Lyman series
- Replies: 2
- Views: 77
Balmer and Lyman series
What exactly characterizes all the lines in the series? I understand it has to do with lower and higher energy states but how exactly are the series grouped together?
This is HW #1A 11.
This is HW #1A 11.
- Sun Oct 06, 2019 12:11 am
- Forum: Empirical & Molecular Formulas
- Topic: Limiting Reactants
- Replies: 4
- Views: 171
Limiting Reactants
Would we ever have to calculate the amount of remaining reactant in a calculation (how much of the reactant that isnt limiting is left)
- Sun Oct 06, 2019 12:10 am
- Forum: Administrative Questions and Class Announcements
- Topic: Test
- Replies: 2
- Views: 84
Test
For the test it says there are only 7 questions, does that mean all the questions are going to be free-response with no multiple choice?
- Sun Oct 06, 2019 12:07 am
- Forum: Empirical & Molecular Formulas
- Topic: Decimals to Whole Numbers
- Replies: 6
- Views: 500
Re: Decimals to Whole Numbers
Usually you want a whole number, but most of the time it doesn't get to an exact number, so I think plus or minus 0.1 should be fine.
- Sun Oct 06, 2019 12:04 am
- Forum: Empirical & Molecular Formulas
- Topic: Hydrates
- Replies: 2
- Views: 157
Hydrates
One of the homework problems requires you to know what a heptahydrate is, is that necessary to know for the test?
- Sun Oct 06, 2019 12:03 am
- Forum: Empirical & Molecular Formulas
- Topic: Chemical Formulas
- Replies: 2
- Views: 178
Chemical Formulas
For the test, do we have to memorize any formulas for certain compounds? Certain questions on the homework expected you to know certain formulas, so want to clarify before the test if there is anything we need to memorize.