Search found 97 matches
- Sat Mar 14, 2020 9:17 pm
- Forum: Balancing Redox Reactions
- Topic: oh
- Replies: 11
- Views: 833
Re: oh
you use OH when you are dealing with basic solutions. You still add H2O to balance the oxygens but the you had OH to make the reaction less acidic and more basic
- Sat Mar 14, 2020 9:15 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final and Work
- Replies: 2
- Views: 378
Re: Final and Work
I was also wondering this. His email made it seem like you would input the answer with no work but maybe there will be other ways to receive points (true or false, multiple choice)
- Sat Mar 14, 2020 9:13 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Cell Diagram
- Replies: 21
- Views: 1226
Re: Cell Diagram
yes, typically we would assume the cathode is on the right and the anode is on the left
- Sat Mar 14, 2020 9:12 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final Exam Time
- Replies: 13
- Views: 958
Re: Final Exam Time
yes it is timed. 3 and a half hours to complete the test
- Sat Mar 14, 2020 9:11 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Grading Scale
- Replies: 16
- Views: 1123
Re: Grading Scale
I think it’ll be pretty much the same. 250 points minimum to pass
- Tue Mar 10, 2020 9:08 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Review Sessions
- Replies: 1
- Views: 214
Re: Review Sessions
I’m not sure but I’m sure Professor Lavelle will email us when he has all the information gathered
- Sun Mar 08, 2020 5:00 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Where do we find the values for A?
- Replies: 5
- Views: 496
Re: Where do we find the values for A?
If you are solving for something besides A, it will be given to you since the constant differs with each equation.
- Sun Mar 08, 2020 4:59 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Elementary reactions
- Replies: 5
- Views: 481
Re: Elementary reactions
Elementary reactions are the steps taken in order to get an overall reaction.
- Sun Mar 08, 2020 4:58 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: catalyst
- Replies: 4
- Views: 431
Re: catalyst
I think it has to do with the catalyst reacting (being a reactant) in the first step and being a product for the next step. An intermediate would begin as a product in the Step 1 or your first reaction. They both don't show up in the final equation.
- Wed Mar 04, 2020 12:25 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Rate Constant, k
- Replies: 4
- Views: 383
Re: Rate Constant, k
Units of k depend on the order of the reaction
0th order= M/s
1st order=1/s
2nd order=1/(M)(s)
0th order= M/s
1st order=1/s
2nd order=1/(M)(s)
- Wed Mar 04, 2020 12:20 pm
- Forum: General Rate Laws
- Topic: Determining Order
- Replies: 6
- Views: 484
Determining Order
How do you determine order of a reaction?
- Thu Feb 27, 2020 6:46 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Where to find Ecell values
- Replies: 15
- Views: 911
Re: Where to find Ecell values
Appendix 2B or you can look it up online
- Thu Feb 27, 2020 6:44 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Calculating n [ENDORSED]
- Replies: 1
- Views: 361
Calculating n [ENDORSED]
When trying to find Delta G using Delta G=-nFE, how do you determine n, number of moles of e- if you are given the reaction?
- Thu Feb 27, 2020 6:42 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Potentials on Test 2
- Replies: 3
- Views: 265
Cell Potentials on Test 2
For test 2, are we going to be given a table for the cell potentials of the half reactions? Some homework problems do not include it, so I am guessing we have to look it up on our own to complete the problem
- Thu Feb 27, 2020 6:39 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Activation Energy
- Replies: 16
- Views: 1521
Re: Activation Energy
The activation energy is the amount of energy needed for the reaction to occur (reactants form products)
- Thu Feb 27, 2020 6:37 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Coefficients in Calculating Cell Potential?
- Replies: 3
- Views: 301
Re: Coefficients in Calculating Cell Potential?
Coefficients do not change standard cell potentials.
- Thu Feb 20, 2020 11:28 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Purpose of Salt Bridge
- Replies: 12
- Views: 845
Purpose of Salt Bridge
Can someone explain what the salt bridge does and how it achieves it's purpose?
- Thu Feb 20, 2020 11:26 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cathode to the Right Rule
- Replies: 6
- Views: 482
Re: Cathode to the Right Rule
The cathode will typically be placed on the right, but you should double check anyways because I have seen diagrams where they are flipped. However, Lavelle made it seem like it will always be on the right for this class.
- Thu Feb 20, 2020 11:21 am
- Forum: Balancing Redox Reactions
- Topic: Understanding Half-Reactions
- Replies: 11
- Views: 731
Re: Understanding Half-Reactions
The half reactions separates the oxidation and reduction that is happening in the reaction. Also it makes it a lot easier to balance if you split them up.
- Thu Feb 20, 2020 11:20 am
- Forum: Balancing Redox Reactions
- Topic: Balancing half reactions
- Replies: 11
- Views: 707
Re: Balancing half reactions
Yes, you have to cancel out the electrons on both sides. Most times you'll have to multiply at least one of the half reactions in order to get the same amount of electrons on each side to be able to cancel them out.
- Thu Feb 20, 2020 11:18 am
- Forum: Balancing Redox Reactions
- Topic: Reduction vs. oxidation
- Replies: 29
- Views: 1243
Re: Reduction vs. oxidation
Oxidation is losing electrons and reduction is gaining electrons (OIL RIG). If the positive charge decreases, it is being reduced. If the positive charge increases, it is being oxidized.
- Wed Feb 19, 2020 12:13 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: rxn gibbs free energy
- Replies: 5
- Views: 378
Re: rxn gibbs free energy
For a reaction to be spontaneous, delta G has to be negative. When delta G is negative, it means the forward reaction is favored and products are formed. When delta G is positive, the opposite happens and reactants are formed.
- Wed Feb 19, 2020 12:10 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Equilibrium
- Replies: 15
- Views: 838
Re: Equilibrium
Since K=1 at equilibrium and the equation is RTln(K), ln(1)=0 making Delta G=0
- Wed Feb 19, 2020 12:08 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Midterm Curve
- Replies: 45
- Views: 2344
Re: Midterm Curve
He does not curve but they are super generous with points and your grade depends on points, not percentage.
- Wed Feb 19, 2020 12:07 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: importance of -RTlnk
- Replies: 7
- Views: 483
Re: importance of -RTlnk
I think its importance is linked back to the way temperature affects it
- Wed Feb 19, 2020 12:05 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: delta G vs. delta G naught
- Replies: 6
- Views: 457
Re: delta G vs. delta G naught
Delta g naught is under standard condition unlike delta G that can be any condition
- Sun Feb 09, 2020 4:04 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Spontaneous rxns
- Replies: 3
- Views: 132
Re: Spontaneous rxns
There are cases where entropy increases due to an increase in volume, but I am not sure if that is the case for all reactions or if the assumption can be made
- Sun Feb 09, 2020 4:02 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: change in entropy
- Replies: 3
- Views: 289
Re: change in entropy
You can us delta H instead of q because at constant pressure, q(p)= delta H
- Sun Feb 09, 2020 3:58 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Cv Cp
- Replies: 3
- Views: 147
Re: Cv Cp
You use it depending on whether you are solving for heat at constant pressure or constant volume. Often times the problem will tell you directly whether it is constant pressure or volume and other times you will have to read the problem carefully and deduce which one it is at.
- Sun Feb 09, 2020 3:53 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Entropy units
- Replies: 7
- Views: 448
Re: Entropy units
I think either Joules or kilo joules is fine as long as you stay consistent throughout the entire problem to make sure no calculation mistakes are made. I would just make sure to read if the question asks for any units in specific
- Sun Feb 09, 2020 3:50 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Free energy
- Replies: 6
- Views: 546
Re: Free energy
I think the standard free energy conditions is the one measured in the lab and the regular free energy change occurs in real life systems
- Mon Feb 03, 2020 7:34 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Combustion
- Replies: 5
- Views: 233
Re: Combustion
Yes at 25 degrees it is in liquid form. If they were to not give you a temperature I would say its safe to assume its in liquid form.
- Mon Feb 03, 2020 7:29 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Value of q
- Replies: 11
- Views: 612
Re: Value of q
The system's q is equal to the -q of the surroundings
- Mon Feb 03, 2020 7:24 pm
- Forum: Calculating Work of Expansion
- Topic: Work done by an ideal gas at isothermal, reversibile expansion
- Replies: 3
- Views: 284
Re: Work done by an ideal gas at isothermal, reversibile expansion
The equation for that is w=-nRTln(V2/V1).
- Mon Feb 03, 2020 7:22 pm
- Forum: Calculating Work of Expansion
- Topic: Calculus on The Midterm
- Replies: 8
- Views: 480
Re: Calculus on The Midterm
I don't think its necessary, but I think he was trying to show how the equation is derived.
- Mon Feb 03, 2020 7:20 pm
- Forum: Calculating Work of Expansion
- Topic: Intergral
- Replies: 6
- Views: 399
Re: Intergral
I think he was just showing how the equation is derived.
- Sun Jan 26, 2020 6:50 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: biological examples
- Replies: 7
- Views: 321
Re: biological examples
I don't remember going over this either. I feel like he might have specifically gone over it in class since that is what he did last quarter in 14A.
- Sun Jan 26, 2020 6:47 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Exothermic reaction
- Replies: 18
- Views: 753
Re: Exothermic reaction
Increasing the temperature will shift the reaction to the left and decreasing it will shift it to the right. This has to do with the fact that exothermic reactions have heat as a product
- Sun Jan 26, 2020 6:43 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Gas Constant
- Replies: 13
- Views: 585
Gas Constant
Which gas constant are we expected to use for the equation PV=nRT?
- Sun Jan 26, 2020 6:42 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Changing K
- Replies: 13
- Views: 541
Re: Changing K
Only temperature can change the value of K.
- Sun Jan 26, 2020 6:37 pm
- Forum: Phase Changes & Related Calculations
- Topic: Why does steam cause burns?
- Replies: 29
- Views: 1337
Re: Why does steam cause burns?
He explained that because steam experiences a phase change when it comes into contact with skin, it releases a big amount of heat and therefore causes severe burns.
- Sun Jan 19, 2020 6:47 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Strong Acids/Bases vs. Weak Acids/Bases
- Replies: 9
- Views: 270
Re: Strong Acids/Bases vs. Weak Acids/Bases
In 14A we had to memorize a list from the textbook, so I'm assuming you just have to refresh your memory on those for this course
- Sun Jan 19, 2020 6:45 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: pKa
- Replies: 13
- Views: 529
Re: pKa
They're inversely related:
lower pKa= stronger acid
higher pKa= weaker acid
lower pKa= stronger acid
higher pKa= weaker acid
- Sun Jan 19, 2020 6:42 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Solids and Liquids
- Replies: 6
- Views: 281
Re: Solids and Liquids
Lavelle mentioned that it had something to do with their concentrations not changing so they were insignificant.
- Sun Jan 19, 2020 6:37 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE Tables
- Replies: 13
- Views: 523
Re: ICE Tables
It's usually because it is in liquid form, but you only include H2O when it is aqueous or gas form.
- Sun Jan 19, 2020 6:34 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: X was ignored
- Replies: 27
- Views: 1194
Re: X was ignored
X was ignored since K was so small (less than 10^-3) and X would make such a small change to .10
- Sun Jan 12, 2020 9:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: memorization
- Replies: 12
- Views: 623
Re: memorization
It's unlikely that we will have to memorize them, but I suggest asking your TA just to be sure.
- Sun Jan 12, 2020 9:17 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K and Q
- Replies: 10
- Views: 325
Re: K and Q
K is the equilibrium constant and Q tells you the constant of the equation when it is not at equilibrium. Q helps you judge whether it is a forward or backwards reaction.
- Sun Jan 12, 2020 9:00 pm
- Forum: Ideal Gases
- Topic: converting Kc to Kp
- Replies: 13
- Views: 479
Re: converting Kc to Kp
Naren_Ramesh_4F wrote:When asked the equilibrium constant of a chemical reaction involving gases, do we solve for Kc or Kp?
You would solve for Kp since the P stands for partial pressure. Remember that if they ask for the equilibrium constant of a gas always assume you use Kp unless stated otherwise.
- Sun Jan 12, 2020 8:58 pm
- Forum: Ideal Gases
- Topic: Test 1
- Replies: 7
- Views: 405
Re: Test 1
The best way to study for the test is to make sure you know what's on his outlines. He goes based off of that for the most part.
- Sun Jan 12, 2020 8:57 pm
- Forum: Ideal Gases
- Topic: Kc and Kp
- Replies: 8
- Views: 321
Re: Kc and Kp
Kc is the equilibrium constant in concentrations and Kp is the equilibrium constant for gases which is in partial pressure.
- Sat Dec 07, 2019 9:51 pm
- Forum: Biological Examples
- Topic: Chemotherapy drugs
- Replies: 7
- Views: 529
Re: Chemotherapy drugs
There are more examples, but this one was talked about heavily in class and at various review sessions.
- Sat Dec 07, 2019 9:47 pm
- Forum: Biological Examples
- Topic: Final
- Replies: 6
- Views: 518
Re: Final
I know some of the more important ones are DNA bonding and cisplatin (the chemotherapy drug talked about in class).
- Sat Dec 07, 2019 9:45 pm
- Forum: Bronsted Acids & Bases
- Topic: Hydrogen Bonding
- Replies: 16
- Views: 1162
Re: Hydrogen Bonding
I think it would just be considered an intermolecular force.
- Sat Dec 07, 2019 9:41 pm
- Forum: Bronsted Acids & Bases
- Topic: Strong Vs. Weak Acids and Bases
- Replies: 3
- Views: 400
Re: Strong Vs. Weak Acids and Bases
It would be helpful! Here are a few
Strong Acids: HCl, H2SO4, HNO3, HI, HBr, HClO4, HClO3
Strong Bases: LiOH, NaOH, Ba(OH)2, KOH, Ca(OH)2
Strong Acids: HCl, H2SO4, HNO3, HI, HBr, HClO4, HClO3
Strong Bases: LiOH, NaOH, Ba(OH)2, KOH, Ca(OH)2
- Sat Dec 07, 2019 9:36 pm
- Forum: Lewis Acids & Bases
- Topic: Strong bases
- Replies: 2
- Views: 220
Re: Strong bases
Some strong bases that you should know are :
LiOH, NaOH, Ba(OH)2, KOH, Ca(OH)2
LiOH, NaOH, Ba(OH)2, KOH, Ca(OH)2
- Sun Dec 01, 2019 8:06 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Curve
- Replies: 3
- Views: 248
Re: Curve
Is it true that we only need 250 points to pass the class?
- Sun Dec 01, 2019 7:45 pm
- Forum: Conjugate Acids & Bases
- Topic: Naming Coordinate Compounds
- Replies: 2
- Views: 234
Re: Naming Coordinate Compounds
Yeah the best way to do it is just to practice a bunch. There's charts with the naming rules that might be helpful if you memorize.
- Sun Dec 01, 2019 7:36 pm
- Forum: Lewis Acids & Bases
- Topic: Proton acceptor and proton donor?
- Replies: 33
- Views: 2220
Re: Proton acceptor and proton donor?
The proton acceptor would be the base and the proton donor is the acid.
- Sun Dec 01, 2019 7:19 pm
- Forum: Dipole Moments
- Topic: Hydrogen Bonding
- Replies: 20
- Views: 1188
Re: Hydrogen Bonding
Yes, hydrogen bonding only occurs when H is bonded with N, O, or F.
- Sun Dec 01, 2019 7:15 pm
- Forum: Hybridization
- Topic: Applying Hybridization
- Replies: 2
- Views: 236
Applying Hybridization
I'm having trouble understanding when to use hybridization or when it's being used, can someone explain?
- Sun Nov 17, 2019 4:16 pm
- Forum: Bond Lengths & Energies
- Topic: Bond Length
- Replies: 22
- Views: 1314
Bond Length
How do we determine bond lengths?
- Sun Nov 17, 2019 4:12 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: AXE formula
- Replies: 32
- Views: 12298
Re: AXE formula
Yes, you should be able to determine the shape of a molecule based on the AXE formula.
- Sun Nov 17, 2019 4:06 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: This Week Test
- Replies: 12
- Views: 777
Re: This Week Test
He said everything that we learned after the midterm will be included in test 2.
- Sun Nov 17, 2019 4:05 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Dipole moments
- Replies: 4
- Views: 209
Re: Dipole moments
The atom points in the direction of the more electronegative atom.
- Sun Nov 17, 2019 4:02 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 1
- Views: 179
Bond Angles
How do you determine the bond angle? Do we have to know the exact angle measurement or just as long as we phrase it as "less than ___"?
- Sun Nov 10, 2019 9:48 pm
- Forum: Bond Lengths & Energies
- Topic: test 2
- Replies: 16
- Views: 926
Re: test 2
I think it will probably be on what we learn after the midterm and maybe include chemical bonding.
- Sun Nov 10, 2019 9:44 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: The exceptions
- Replies: 6
- Views: 426
Re: The exceptions
Copper and Chromium are two exceptions.
- Sun Nov 10, 2019 9:42 pm
- Forum: Lewis Structures
- Topic: Does the shape that I draw the Lewis structure matter?
- Replies: 14
- Views: 1038
Re: Does the shape that I draw the Lewis structure matter?
Shape will probably matter when we go over that lecture, but right now it does not matter.
- Sun Nov 10, 2019 9:40 pm
- Forum: Lewis Structures
- Topic: Midterm grades
- Replies: 26
- Views: 1487
Re: Midterm grades
I believe it is Wednesday, but if not then by Friday.
- Tue Nov 05, 2019 12:13 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Magnetic Quantum numbers
- Replies: 4
- Views: 740
Magnetic Quantum numbers
What are magnetic quantum numbers and how do you find them?
- Wed Oct 30, 2019 11:39 pm
- Forum: Properties of Electrons
- Topic: Knowing masses
- Replies: 2
- Views: 261
Knowing masses
Are expected to memorize the masses of electrons, protons, and neutrons? Only asking because the homework has problems where these values are not given in the problem.
- Wed Oct 30, 2019 2:33 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: d block before s block
- Replies: 3
- Views: 223
d block before s block
Can somebody explain why you would put 3d^6 4s^2 instead of the other way around?
- Wed Oct 30, 2019 2:30 am
- Forum: Photoelectric Effect
- Topic: When energy is equal to work function
- Replies: 9
- Views: 1018
Re: When energy is equal to work function
When the energy of the photon is equal to the work function, the electron will be ejected. However, there will no excess energy (kinetic energy).
- Wed Oct 30, 2019 2:27 am
- Forum: Photoelectric Effect
- Topic: Increasing Light Intensity Photoelectric Effect
- Replies: 7
- Views: 923
Re: Increasing Light Intensity Photoelectric Effect
Yes, as long as the frequency is equal to or greater than the threshold energy needed to eject an electron, increasing the light intensity will increase the # of electrons ejected. It won't affect the kinetic energy.
- Wed Oct 30, 2019 2:22 am
- Forum: *Black Body Radiation
- Topic: Info for Midterm
- Replies: 13
- Views: 1181
Info for Midterm
What exactly do we need to know about black body radiation for the midterm?
- Wed Oct 30, 2019 2:20 am
- Forum: Ionic & Covalent Bonds
- Topic: Homework for Week 5
- Replies: 8
- Views: 356
Homework for Week 5
Do we need to do homework for chemical bonding this week or can we still do quantum to review?
- Sat Oct 26, 2019 5:55 pm
- Forum: Trends in The Periodic Table
- Topic: Ionization Energy
- Replies: 7
- Views: 560
Re: Ionization Energy
The ionization energy of the second electron is always higher because when you remove an electron, the pull between protons and electrons become stronger (requiring more energy to remove)
- Sat Oct 26, 2019 5:44 pm
- Forum: Resonance Structures
- Topic: Formal Charge
- Replies: 13
- Views: 1434
Re: Formal Charge
Usually, you want the central atom to be the one with the formal charge of 0 if it is not possible for all atoms to have a formal charge of zero.
- Sat Oct 26, 2019 5:31 pm
- Forum: Lewis Structures
- Topic: Drawing Lewis Structures
- Replies: 8
- Views: 269
Re: Drawing Lewis Structures
Hydrogen is an exception. It will never be the central atom.
- Sat Oct 26, 2019 5:25 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Electron Configuration
- Replies: 1
- Views: 337
Electron Configuration
Can somebody break down how to figure out electron configuration?
- Sat Oct 26, 2019 1:57 am
- Forum: Trends in The Periodic Table
- Topic: Ionization energy
- Replies: 12
- Views: 648
Ionization energy
Are we expected to know a specific formula for ionization energy or only the general trends of ionization energy?
- Sun Oct 20, 2019 10:14 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Spin up and spin down
- Replies: 13
- Views: 1204
Re: Spin up and spin down
Do we always assume that it's spin up and spin down for this class?
- Sun Oct 20, 2019 9:54 pm
- Forum: Properties of Light
- Topic: Midterm Exam
- Replies: 21
- Views: 734
Re: Midterm Exam
If the class isn't curved, how many points are needed to pass the class? I remember reading something about using the class average at the end and needing at least 50% on the syllabus.
- Sun Oct 20, 2019 9:50 pm
- Forum: Properties of Light
- Topic: What are the units of hertz
- Replies: 41
- Views: 2227
Re: What are the units of hertz
Hz would be s^-1 which implies 1 cycle per second
- Sun Oct 20, 2019 9:49 pm
- Forum: Properties of Light
- Topic: homework 1A.3
- Replies: 8
- Views: 297
Re: homework 1A.3
When frequency decreases, the wavelength would increase because you'd be dividing the speed of light by a smaller frequency. wavelength= (speed of light)/(frequency)
- Sun Oct 20, 2019 9:46 pm
- Forum: Properties of Light
- Topic: Next test
- Replies: 23
- Views: 1117
Re: Next test
We should be getting an equation sheet with constants as well, if I'm not mistaken.
- Sun Oct 13, 2019 10:26 pm
- Forum: Properties of Electrons
- Topic: Photons
- Replies: 5
- Views: 354
Re: Photons
So only the change in energy of a photon can be negative?
- Sun Oct 13, 2019 4:04 pm
- Forum: Properties of Electrons
- Topic: Photons
- Replies: 5
- Views: 354
Photons
Can somebody explain why the energy of a photon is always positive?
- Sun Oct 13, 2019 3:55 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: M1V1=M2V2
- Replies: 11
- Views: 87107
Re: M1V1=M2V2
This equation can be used when you are given any of the three values needed for the completion of the equation. For example if you are asked to find the V1, you will need to have M1, M2, and V2 in order to be able to use this equation.
- Sun Oct 13, 2019 3:52 pm
- Forum: Empirical & Molecular Formulas
- Topic: Converting from grams to percentage
- Replies: 11
- Views: 7690
Re: Converting from grams to percentage
You should convert the grams to a percentage when you are given the amount of grams of each element and the total mass of the compound to find the mass percentage composition. Then assuming you have 100 g, you would convert the percentage to grams and then moles. Sometimes the mass percentage compos...
- Sun Oct 13, 2019 3:45 pm
- Forum: Significant Figures
- Topic: How many significant figures are in 7.00 x 10^2?
- Replies: 25
- Views: 3653
Re: How many significant figures are in 7.00 x 10^2?
You would have 3 significant figures because the zeros after the decimal are counted as significant figures.
- Sun Oct 06, 2019 8:15 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Theoretical vs. Actual Yield
- Replies: 38
- Views: 14167
Re: Theoretical vs. Actual Yield
The theoretical yield is what you're supposed to get if there are no errors or other factors that affect the experiment. However sometimes factors such as the experiment sticking to the side of the test tube will reduce the amount of yield (actual yield).
- Sun Oct 06, 2019 8:06 pm
- Forum: Balancing Chemical Reactions
- Topic: H.19
- Replies: 2
- Views: 252
H.19
Hi, I could use some help doing homework problem H.19:
Write balanced equation for the combustion of the solid C11H18N2O5 to carbon dioxide gas, liquid water, and nitrogen gas.
Write balanced equation for the combustion of the solid C11H18N2O5 to carbon dioxide gas, liquid water, and nitrogen gas.
- Sun Oct 06, 2019 7:56 pm
- Forum: Administrative Questions and Class Announcements
- Topic: using older edition textbook
- Replies: 8
- Views: 545
Re: using older edition textbook
I've heard the 6th edition and the 7th edition are pretty much the same, but you might want to ask your TA to be sure that you can use any other edition besides the 7th.
- Sun Oct 06, 2019 7:53 pm
- Forum: SI Units, Unit Conversions
- Topic: Sig figs
- Replies: 5
- Views: 216
Re: Sig figs
That .0 makes the difference between only using one sig fig and using 3 sig figs.
- Sun Oct 06, 2019 7:42 pm
- Forum: Significant Figures
- Topic: Number of significant figures
- Replies: 5
- Views: 425
Re: Number of significant figures
You're supposed to go based off the value with lowest significant figures given in the problem. For example, if you were given the values 6.38 and 43.58 in a homework problem, your final answer should include 3 significant figures.