Search found 101 matches
- Sun Mar 14, 2021 9:45 pm
- Forum: Student Social/Study Group
- Topic: How to Reduce Nervousness before getting results
- Replies: 63
- Views: 6499
Re: How to Reduce Nervousness before getting results
I feel like the easiest way to not be nervous is to not think about it. The test is done and over with, and whatever happens now wont affect your score. There is nothing you can do now so being patient and relaxed is key.
- Sun Mar 14, 2021 9:44 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Salt Bridges
- Replies: 12
- Views: 976
Re: Salt Bridges
Salt bridges allow the transfer of electrons across the cell, which in turn stops one side from building up too much of a charge.
- Sun Mar 14, 2021 9:43 pm
- Forum: General Science Questions
- Topic: No Lavelle Chem 14C?
- Replies: 68
- Views: 6522
Re: No Lavelle Chem 14C?
No Lavelle does not teach 14C, only 14A and B :(
- Sun Mar 14, 2021 9:42 pm
- Forum: General Rate Laws
- Topic: Youtube Review
- Replies: 17
- Views: 1068
Re: Youtube Review
Organic Chemistry Tutor or Professor Dave are very good resources on youtube, I think they both explain this material very well
- Sun Mar 14, 2021 9:40 pm
- Forum: *Enzyme Kinetics
- Topic: catalyst
- Replies: 23
- Views: 2864
Re: catalyst
enzymes are catalysts because they lower the activation energy for a reaction, but aren't used up in the reaction
- Sun Mar 07, 2021 5:26 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Intermediates and Catalysts
- Replies: 1
- Views: 144
Intermediates and Catalysts
How are we able to tell which letters in question 18 on sapling are intermediates and which ones are catalysts.
- Sun Mar 07, 2021 5:25 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: HW Question
- Replies: 2
- Views: 183
HW Question
A certain reaction has an activation energy of 33.82 kJ/mol. At what Kelvin temperature will the reaction proceed 4.50 times faster than it did at 343 K?
Im confused on how to solve this.
Im confused on how to solve this.
- Sun Mar 07, 2021 5:24 pm
- Forum: First Order Reactions
- Topic: Half Life caluclations
- Replies: 6
- Views: 372
Re: Half Life caluclations
You find this by seeing how many times you need to divide the first concentration by 2 in order to get to the second concentration.
- Sun Mar 07, 2021 5:22 pm
- Forum: Balancing Redox Reactions
- Topic: How to Determine if a Reaction is in Basic or Acidic Solution?
- Replies: 53
- Views: 3686
Re: How to Determine if a Reaction is in Basic or Acidic Solution?
The question will likely tell you, so then you will know how to balance the redox reaction.
- Sun Mar 07, 2021 5:22 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final
- Replies: 48
- Views: 3262
Re: Final
The textbook problems help a lot. By doing those and reviewing past notes I think you will do just fine!
- Sun Feb 28, 2021 11:59 am
- Forum: Ideal Gases
- Topic: STP
- Replies: 12
- Views: 1656
Re: STP
STP is 0 degrees Celsius, which is 273 K. Normally we see 298 K because that is 25 degrees Celsius, or around room temp.
- Sun Feb 28, 2021 11:56 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Adding Pt(s) to the cell diagram
- Replies: 13
- Views: 592
Re: Adding Pt(s) to the cell diagram
In an aqueous solution you need P(t) to be an electron conductor
- Sun Feb 28, 2021 11:55 am
- Forum: Calculating Work of Expansion
- Topic: Finding Reversibility
- Replies: 8
- Views: 564
Re: Finding Reversibility
You can tell that a reaction is reversible if he delta S total equals 0. It can also be found if you are given moles, temp, and the change in volume.
- Sun Feb 28, 2021 11:52 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: HW Question
- Replies: 2
- Views: 207
HW Question
Calculate the cell potential for the reaction as written at 25.00 °C , given that [Zn2+]=0.819 M and [Ni2+]=0.0160 M . Use the standard reduction potentials in this table. Zn(s)+Ni2+(aq)↽−−⇀ Zn2+(aq)+Ni(s) This is my question for #14, but how do we tell which one is the anode and which is the cathod...
- Sun Feb 28, 2021 11:46 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: HW Question
- Replies: 4
- Views: 380
HW Question
What would the potential of a standard hydrogen electrode (S.H.E.) be under the given conditions?
[H+]=0.40 M. PH2=1.8 atm T=298 K
Does anyone know how to do this?
[H+]=0.40 M. PH2=1.8 atm T=298 K
Does anyone know how to do this?
- Sun Feb 21, 2021 3:53 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: HW Question
- Replies: 1
- Views: 152
HW Question
A galvanic (voltaic) cell consists of an electrode composed of aluminum in a 1.0 M aluminum ion solution and another electrode composed of copper in a 1.0 M copper(I) ion solution, connected by a salt bridge. Calculate the standard potential for this cell at 25 °C. Im trying to get a head start on t...
- Sun Feb 21, 2021 3:52 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: delta U=0
- Replies: 17
- Views: 2742
Re: delta U=0
In Isothermal reactions the temperature is constant, so there is no heat transfer. In these reactions q=-w, so they cancel out and leave delta U equal to 0.
- Sun Feb 21, 2021 3:49 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem community points
- Replies: 10
- Views: 642
Re: Chem community points
We should have 35 points for this quarter, and 85 in total if you took 14A with Lavelle.
- Sun Feb 21, 2021 2:26 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: State function?
- Replies: 36
- Views: 1635
Re: State function?
E is not a state function, it relies on the path that was taken in order to get to the current state.
- Sun Feb 21, 2021 2:25 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Can We Review our Exams?
- Replies: 69
- Views: 4269
Re: Can We Review our Exams?
Yes you can review your test with a TA in their office hours. It doesn't have to be your TA either, it can be any.
- Sun Feb 14, 2021 11:33 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Entropy
- Replies: 27
- Views: 1279
Re: Entropy
Entropy is also a state function that shows the number of microstates possible. There are many topics that cover this, and a few equations, so i think it will be important for this next midterm.
- Sun Feb 14, 2021 11:31 pm
- Forum: Student Social/Study Group
- Topic: Points needed to pass?
- Replies: 76
- Views: 11120
Re: Points needed to pass?
You need to get 200 or more points to pass with a C-.
- Sun Feb 14, 2021 11:29 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: HW Question
- Replies: 4
- Views: 364
HW Question
For a gaseous reaction, standard conditions are 298 K and a partial pressure of 1 bar for all species. For the reaction C2H6(g)+H2(g)↽−−⇀2CH4(g) the standard change in Gibbs free energy is ΔG∘=−32.8 kJ/mol. What is ΔG for this reaction at 298 K when the partial pressures are PC2H6=0.200 bar, PH2=0.1...
- Sun Feb 14, 2021 11:23 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: HW Question
- Replies: 3
- Views: 231
HW Question
The ΔHvap of a certain compound is 14.23 kJ·mol−1 and its ΔSvap is 75.76 J·mol−1·K−1.
What is the boiling point of this compound?
How do I do this?
What is the boiling point of this compound?
How do I do this?
- Sun Feb 14, 2021 11:21 pm
- Forum: Student Social/Study Group
- Topic: Valentine's Day Long Weekend!
- Replies: 30
- Views: 2432
Re: Valentine's Day Long Weekend!
Happy Valentines day to you too!
- Sun Feb 07, 2021 8:44 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Friday's Lecture
- Replies: 8
- Views: 384
Re: Friday's Lecture
This only applies when delta U=0. The first law of thermodynamics supports this equation.
- Sun Feb 07, 2021 12:38 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: HW Question
- Replies: 4
- Views: 471
HW Question
A 0.253 mol sample of CO2(g) initially at 298 K and 1.00 atm is held at constant volume while enough heat is applied to raise the temperature of the gas by 17.5 K. Assuming ideal gas behavior, calculate the amount of heat (q) in joules required to affect this temperature change and the total change ...
- Sun Feb 07, 2021 12:32 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: Positive and Negative q Value
- Replies: 19
- Views: 13672
Re: Positive and Negative q Value
q would be negative if the system is exothermic, or releasing heat. And q would be positive if it is endothermic, or taking in heat.
- Sun Feb 07, 2021 12:29 pm
- Forum: Student Social/Study Group
- Topic: Study routine.
- Replies: 51
- Views: 3297
Re: Study routine.
Personally, I find the homework questions from the outline to be a very good study technique. You can review the ones you struggle on over and over and once you have a good grip on these you should be pretty good for the test. Also, a lot of times Dr. Lavelle sneaks some of these questions into the ...
- Sun Feb 07, 2021 12:15 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: HW Question
- Replies: 2
- Views: 183
HW Question
A constant‑volume calorimeter was calibrated by carrying out a reaction known to release 2.14 kJ of heat in 0.300 L of solution in the calorimeter (q=−2.14 kJ) , resulting in a temperature rise of 3.80 ∘C . In a subsequent experiment, 150.0 mL of 0.20 M HClO2(aq) and 150.0 mL of 0.20 M NaOH(aq) were...
- Sun Jan 31, 2021 4:35 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Molar Heat Capacity
- Replies: 11
- Views: 392
Re: Molar Heat Capacity
Well we know that it is the heat required to raise one mole of a substance by 1 degrees Celcius, we may have to use these on textbook problems.
- Sun Jan 31, 2021 4:20 pm
- Forum: Ideal Gases
- Topic: Chem BL
- Replies: 107
- Views: 11279
Chem BL
When do you guys plan on taking Chem 14BL? I dont know if I should take both Chem 14C and Chem 14BL together, what is everyone else doing? thank you!
- Sun Jan 31, 2021 3:53 pm
- Forum: Calculating Work of Expansion
- Topic: HW Question
- Replies: 2
- Views: 175
HW Question
A sample of an ideal gas in a cylinder of volume 2.61 L at 298 K and 2.22 atm expands to 7.61 L by two different pathways. Path A is an isothermal, reversible expansion. Path B has two steps. In the first step, the gas is cooled at constant volume to 1.15 atm . In the second step, the gas is heated ...
- Sun Jan 31, 2021 3:52 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: HW Question
- Replies: 3
- Views: 94
HW Question
A hot lump of 27.8 g of copper at an initial temperature of 50.8 °C is placed in 50.0 mL H2O initially at 25.0 °C and allowed to reach thermal equilibrium. What is the final temperature of the copper and water, given that the specific heat of copper is 0.385 J/(g·°C)? Assume no heat is lost to surro...
- Sun Jan 31, 2021 3:50 pm
- Forum: Thermodynamic Systems (Open, Closed, Isolated)
- Topic: isolated system
- Replies: 16
- Views: 939
Re: isolated system
yes because it can not exchange energy or matter with the surrounding environment
- Sun Jan 24, 2021 7:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Strong vs weak acids/bases
- Replies: 6
- Views: 394
Re: Strong vs weak acids/bases
You would use the ICE table for weak acids/bases because they do not completely dissociate during a reaction, so we have to calculate how much changes using x.
- Sun Jan 24, 2021 7:36 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Rounding E Values in ICE charts
- Replies: 17
- Views: 754
Re: Rounding E Values in ICE charts
Normally, anything smaller than 1x10^-4 is safe to assume, however I would always check that it is less than 5% of the initial concentration. If it is not then you need to use the quadratic equation to find x for that problem.
- Sun Jan 24, 2021 7:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pH of salt/bases
- Replies: 4
- Views: 258
Re: pH of salt/bases
Actually the tables on 6C.1 and 6C.2 show you! I would just memorize those.
- Sat Jan 23, 2021 2:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW Question
- Replies: 5
- Views: 420
Re: HW Question
I think the hardest part is just knowing where to start, as you said. Although normally we have done ICE tables for the equilibriums of weak acid, this question gives us a weak base and the process is the exact same. First, write out the equation for the weak base NaClO in solution. When dissolved ...
- Fri Jan 22, 2021 7:54 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW Question
- Replies: 5
- Views: 420
HW Question
HClO is a weak acid ( Ka=4.0×10−8 ) and so the salt NaClO acts as a weak base. What is the pH of a solution that is 0.037 M in NaClO at 25 °C?
Can you guys help me solve this problem, I don't know where to start.
Can you guys help me solve this problem, I don't know where to start.
- Wed Jan 20, 2021 9:12 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW Question
- Replies: 3
- Views: 192
HW Question
If the Ka of a monoprotic weak acid is 8.6×10−6, what is the pH of a 0.33 M solution of this acid?
How would I do this problem?
How would I do this problem?
- Sun Jan 17, 2021 10:20 pm
- Forum: Ideal Gases
- Topic: Kp?
- Replies: 30
- Views: 1174
Re: Kp?
Yes, partial pressure only applies to gases.
- Sun Jan 17, 2021 10:19 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Week 1 #6
- Replies: 10
- Views: 449
Re: Sapling Week 1 #6
You find Q by using the equation Q=products/reactants. Make sure you remember that the numbers in front get used as exponents, and products go on top.
- Sun Jan 17, 2021 10:16 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Total Pressure
- Replies: 26
- Views: 2201
Re: Total Pressure
Total pressure is all pressures combined at equilibrium. It is found by adding up the partial pressures of all the compounds in a reaction.
- Sun Jan 17, 2021 10:15 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Week 1 #9
- Replies: 3
- Views: 217
Re: Sapling Week 1 #9
Im honestly struggling to see any faults in your work. Was your final answer 0.825 M? If it was I do not know, maybe contact your TA to help.
- Fri Jan 15, 2021 8:46 pm
- Forum: Ideal Gases
- Topic: Hw Question #4
- Replies: 5
- Views: 301
Hw Question #4
At a certain temperature, the given reaction has an equilibrium constant of Kp=369 .
PCl3(g)+Cl2(g)↽−−⇀PCl5(g)
PCl5 is placed in a sealed container at an initial pressure of 0.0800 bar . What is the total pressure at equilibrium?
How would I go about doing this?
PCl3(g)+Cl2(g)↽−−⇀PCl5(g)
PCl5 is placed in a sealed container at an initial pressure of 0.0800 bar . What is the total pressure at equilibrium?
How would I go about doing this?
- Sun Jan 10, 2021 1:16 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: H2O
- Replies: 44
- Views: 2269
Re: H2O
The only time that this is included in the table is when it is in gas (g) form. The compound is not included if it is in liquid or solid phases.
- Sun Jan 10, 2021 1:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Picking Value when doing Quadratic Equation
- Replies: 10
- Views: 481
Re: Picking Value when doing Quadratic Equation
Based on the results you get, one should be the obvious answer. For example, if your two answers are 2 and -2, the answer is 2 as you use the positive number. Additionally, if that number is larger than the original concentration, then it won't be the answer. You can't have more of a change than the...
- Sun Jan 10, 2021 1:07 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW Question
- Replies: 2
- Views: 134
HW Question
At a certain temperature, 0.820 mol SO3 is placed in a 4.50 L container.
2SO3(g)↽−−⇀2SO2(g)+O2(g)
At equilibrium, 0.170 mol O2 is present. Calculate Kc.
For this would you just have to find the molarity of each compound and then plug it into the equation for Kc?
2SO3(g)↽−−⇀2SO2(g)+O2(g)
At equilibrium, 0.170 mol O2 is present. Calculate Kc.
For this would you just have to find the molarity of each compound and then plug it into the equation for Kc?
- Sun Jan 10, 2021 1:05 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: HW Question
- Replies: 8
- Views: 405
HW Question
Consider the reaction of NH3 and I2 to give N2 and HI. 2NH3(g)+3I2(g)↽−−⇀N2(g)+6HI(g)K Using two or more of the given equations, determine the equilibrium constant, K , for the reaction of NH3 with I2. H2(g)+I2(g)↽−−⇀2HI(g)I2(g)↽−−⇀2I(g)N2(g)+3H2(g)↽−−⇀2NH3(g)H2(g)+Cl2(g)↽−−⇀2HCl(g)Ka=160Kb=2.1×10−3...
- Sun Jan 10, 2021 1:00 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Units
- Replies: 27
- Views: 1120
Re: Units
I believe for pressure bars are what we use (they are very similar to atm).
- Tue Dec 15, 2020 3:22 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: What are the bond angles for T shaped?
- Replies: 21
- Views: 8888
Re: What are the bond angles for T shaped?
Slightly less than 90 degrees as the electron pairs have repulsion.
- Tue Dec 15, 2020 3:04 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chem community points
- Replies: 16
- Views: 883
Re: Chem community points
The new due date is thursday, so it wont be updated until then!
- Tue Dec 15, 2020 3:01 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Square Planar vs. Tetrahedral [ENDORSED]
- Replies: 18
- Views: 1690
Re: Square Planar vs. Tetrahedral [ENDORSED]
Tetrahedral has 4 bonds to atoms, and no lone pairs (AX4). Square planar has 4 bonds to atoms, and 2 lone pairs(AX4E2).
- Tue Dec 15, 2020 2:59 pm
- Forum: Student Social/Study Group
- Topic: Curve
- Replies: 33
- Views: 2780
Re: Curve
There is no curve, but he did say that he is adding 10 points to the final grade. That should help!
- Tue Dec 15, 2020 2:58 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Ground State of H
- Replies: 3
- Views: 505
Re: Ground State of H
yes! that is what that means!
- Sun Dec 06, 2020 9:13 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: HW Question coordination number
- Replies: 4
- Views: 205
HW Question coordination number
After guessing a few times I got that the coordination number for [Co(SO4)(NH3)5]+ is 6.
Does anyone know why this is?
Does anyone know why this is?
- Sun Dec 06, 2020 9:08 pm
- Forum: Properties of Light
- Topic: Photoelectric Effect
- Replies: 14
- Views: 945
Re: Photoelectric Effect
Yes it is. The energy of the photon-the threshold energy is = to the kinetic energy.
- Sun Dec 06, 2020 9:03 pm
- Forum: Properties of Light
- Topic: Is c always the speed of light?
- Replies: 92
- Views: 6765
Re: Is c always the speed of light?
In this case, this will only be the speed of light. It may change in future classes (I'm not sure), but for now this is the speed of light. The constant is around 3 x 10^8
- Sun Dec 06, 2020 8:56 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How to find coordination number.
- Replies: 10
- Views: 3722
Re: How to find coordination number.
To find the coordination number, you need to look at how many ligands are connected to the central atom. For example, in the compound [CuCl2]-, the coordination number is 2. There are 2 Cl atoms around the Cu atom. Another example would be Ba[FeBr4]2. Since you only count whats on the inside of the ...
en
When naming compounds, what does en mean?
- Sat Dec 05, 2020 9:40 pm
- Forum: Lewis Acids & Bases
- Topic: Application to the Period Table
- Replies: 6
- Views: 331
Re: Application to the Period Table
From the lectures, we learn that the left side (alkali metals) usually give rise to base oxidation. On the right side you generally see acid oxides being formed from the halogens, etc. In the middle, near the transition metals and metalloids you will see amphoteric atoms. Hope this helps!
- Sat Dec 05, 2020 9:34 pm
- Forum: Dipole Moments
- Topic: Polarity from Shape
- Replies: 12
- Views: 760
Re: Polarity from Shape
Bent molecules are asymmetrical, generally leading to a polar molecule. For example, since water is bent and the two H atoms are electronegative towards the O atom, it does not cancel out. This is why water is polar, and most bent molecules follow that trend.
- Sat Dec 05, 2020 9:23 pm
- Forum: Lewis Acids & Bases
- Topic: Bronsted vs. Lewis bases
- Replies: 11
- Views: 445
Re: Bronsted vs. Lewis bases
They are similar, but have some differences. A Lewis base is a base in which an electron is donated to another atom. A Bronsted base is one who accepts a proton (from an H), making that atom basic. They talk about different reactions but lead to the same concept.
- Sat Dec 05, 2020 8:59 pm
- Forum: Naming
- Topic: HW Question #1
- Replies: 7
- Views: 471
HW Question #1
Does anyone know how to answer this? My questions asks what the name of this compound is. Thank you!
[Co(NH3)4Cl2]Cl
[Co(NH3)4Cl2]Cl
- Sat Dec 05, 2020 8:56 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Numbers
- Replies: 8
- Views: 571
Re: Coordination Numbers
Hi! Coordination number refers to the number of ligand atoms bonding to the central transition metal. For example, if the compound is ZnCl4 there are 4 chlorine atoms bound to the central atom, Zinc. If you have brackets (e.g K4[Fe(Cn)6]-) you would only count the atoms on the inside. So in this cas...
- Sun Nov 22, 2020 12:44 pm
- Forum: Hybridization
- Topic: HW Question
- Replies: 3
- Views: 148
HW Question
What is the hybridization of phosphorus in each of the molecules or ions?
The first molecule shown is PCl3
thank you!
The first molecule shown is PCl3
thank you!
- Sun Nov 22, 2020 12:41 pm
- Forum: Lewis Structures
- Topic: Central Atom Question
- Replies: 20
- Views: 1295
Re: Central Atom Question
H will never be the central atom because it is only allowed to form 1 bond to fill its octet.
- Sun Nov 22, 2020 12:40 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Expanded Octets
- Replies: 9
- Views: 457
Re: Expanded Octets
Usually, atoms after the 3p subshell can have an expanded octet, but I'm not sure what the rule is for atoms in the 6p subshell.
- Sun Nov 22, 2020 12:38 pm
- Forum: Trends in The Periodic Table
- Topic: Ionic Character
- Replies: 11
- Views: 582
Ionic Character
How do you determine ionic/covalent character again?
There was a question on the midterm that I was stuck on.
There was a question on the midterm that I was stuck on.
- Sun Nov 22, 2020 12:36 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sapling #4
- Replies: 5
- Views: 267
Sapling #4
How many outer atoms and lone pairs are present in a molecule with a see‑saw shape?
Do you guys know?
Do you guys know?
- Sun Nov 15, 2020 9:33 pm
- Forum: Ionic & Covalent Bonds
- Topic: midterm 2: knowing compounds
- Replies: 14
- Views: 644
Re: midterm 2: knowing compounds
Because we haven't been taught nomenclature of names of compounds yet they will be provided in this midterm.
- Sun Nov 15, 2020 9:29 pm
- Forum: Ionic & Covalent Bonds
- Topic: Homework due date
- Replies: 49
- Views: 2685
Re: Homework due date
Sunday at 11:59 pm, not Sunday at 12:00 am.
- Sun Nov 15, 2020 9:28 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Oxidation Sapling 9
- Replies: 6
- Views: 455
Oxidation Sapling 9
Using number 9 in the sapling hw as an example, how do you find the oxidation number? And how do you know which structure is applies to? Thank you!
- Sun Nov 15, 2020 9:26 pm
- Forum: General Science Questions
- Topic: Midterm 2
- Replies: 12
- Views: 890
Re: Midterm 2
The last 8 on outline 2 and all of outline 3!
- Sun Nov 15, 2020 6:06 pm
- Forum: Bond Lengths & Energies
- Topic: Hydrogen Bonding
- Replies: 13
- Views: 488
Re: Hydrogen Bonding
Hi! There are no exceptions, only happens when F, O, N, H are present.
- Sun Nov 08, 2020 11:29 pm
- Forum: SI Units, Unit Conversions
- Topic: conversion factors
- Replies: 8
- Views: 511
Re: conversion factors
Nope, any ones that aren't given on the constants and equations sheet will be given in the problem!
- Sun Nov 08, 2020 11:27 pm
- Forum: Student Social/Study Group
- Topic: Mid-quarter Check in
- Replies: 67
- Views: 4820
Re: Mid-quarter Check in
I hate online school, I wish we were on campus!
- Sun Nov 08, 2020 11:23 pm
- Forum: Ionic & Covalent Bonds
- Topic: HW Question
- Replies: 4
- Views: 898
HW Question
Select which intermolecular forces of attraction are present between CH3CHO molecules.
does anyone know what they are?
does anyone know what they are?
- Sun Nov 08, 2020 11:21 pm
- Forum: Ionic & Covalent Bonds
- Topic: HW Question
- Replies: 2
- Views: 150
HW Question
Urea is an organic compound widely used as a fertilizer. Its solubility in water allows it to be made into aqueous fertilizer solutions and applied to crops in a spray. What is the maximum theoretical number of water molecules that one urea molecule can hydrogen bond with? Ignore shape for the purpo...
- Sun Nov 08, 2020 11:16 pm
- Forum: Student Social/Study Group
- Topic: Veterans Day
- Replies: 16
- Views: 805
Re: Veterans Day
My other classes are having us change to another day, so i'm guessing it is either cancelled or postponed.
- Sun Nov 01, 2020 6:39 pm
- Forum: Student Social/Study Group
- Topic: Sappling #27
- Replies: 3
- Views: 226
Re: Sappling #27
No it is not relevant, just plug in the uncertainty in velocity to find the uncertainty in position.
- Sun Nov 01, 2020 6:13 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: Question 26 Sapling
- Replies: 5
- Views: 474
Question 26 Sapling
On the Sapling HW, it asks
What is the minimum uncertainty in an electron's velocity (Δvmin) if the position is known within 13 Å.
How do I solve this?
What is the minimum uncertainty in an electron's velocity (Δvmin) if the position is known within 13 Å.
How do I solve this?
- Sun Nov 01, 2020 6:12 pm
- Forum: DeBroglie Equation
- Topic: energy of a photon
- Replies: 7
- Views: 490
energy of a photon
Question #25 asks
The E Coli bacterium is about 2.4 μm long. Suppose you want to study it using photons of that wavelength or electrons having that de Broglie wavelength.
What is the energy E photon of the photon?
How do I solve this?
The E Coli bacterium is about 2.4 μm long. Suppose you want to study it using photons of that wavelength or electrons having that de Broglie wavelength.
What is the energy E photon of the photon?
How do I solve this?
- Sat Oct 31, 2020 4:43 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: N levels for electron configurations
- Replies: 6
- Views: 377
Re: N levels for electron configurations
The l # represents the subshell. In this case, when l=1 it represents the p subshell. As we know, there can be a total of 6 electrons. To take it even further, they could ask using the ml value as well. For the p subshell, there are three possible orbitals: -1, 0, and 1. We know that each orbital ca...
- Sat Oct 31, 2020 4:30 pm
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity
- Replies: 2
- Views: 160
Electron Affinity
Here is my question on number 23. The electron affinity of thulium has been measured by a technique known as laser photodetachment electron spectroscopy. In this technique, a gaseous beam of the anions of an element is bombarded with photons from a laser. Electrons from the anion are then ejected an...
- Wed Oct 28, 2020 9:27 pm
- Forum: DeBroglie Equation
- Topic: Conversions
- Replies: 10
- Views: 635
Conversions
Im studying for the midterm and going over questions from the book. There is one asking you to find the wavelength of a baseball traveling 92 mph, and I know how to solve it. However, I know that you need a number to convert miles to kilometers, will we need to memorize this and other conversions fo...
- Sat Oct 24, 2020 2:07 pm
- Forum: Einstein Equation
- Topic: Usage of E=hv
- Replies: 10
- Views: 548
Re: Usage of E=hv
Yes this is used for photons as there is no mass, but when there is mass (an electron has a constant mass listed on the constants sheet) then you use DeBroglie's equation to solve for wavelength. Hope this helped!
- Sat Oct 24, 2020 2:02 pm
- Forum: Student Social/Study Group
- Topic: Midterm Prep
- Replies: 15
- Views: 746
Re: Midterm Prep
My TA said that it would be around 10 questions, with no more than 4 long multiple step problems. To study I recommend doing the book questions and going over lectures.
- Sat Oct 24, 2020 1:57 pm
- Forum: Properties of Light
- Topic: Constants
- Replies: 21
- Views: 753
Re: Constants
I would use how ever many are shown on the sheet of equations and constants that we print out, but the more that you use the closer your answer will be to the correct answer.
- Mon Oct 19, 2020 3:41 pm
- Forum: DeBroglie Equation
- Topic: Question about 10/19/2020 lecture regarding DeBrogile Equation example
- Replies: 4
- Views: 203
Re: Question about 10/19/2020 lecture regarding DeBrogile Equation example
That number is the universal mass of an electron. I'm guessing we don't have to memorize it, if it's on the midterm i'm sure it will be provided.
- Sun Oct 18, 2020 2:40 pm
- Forum: Photoelectric Effect
- Topic: Practice Quiz Question
- Replies: 3
- Views: 110
Practice Quiz Question
In my practice quiz, the question had the unit keV. What is that?
- Sun Oct 18, 2020 2:36 pm
- Forum: Einstein Equation
- Topic: m vs nm
- Replies: 66
- Views: 4237
Re: m vs nm
If the question asks, then I assume that you would need to convert to nm. However, if it doesn't mention anything Lavelle said that meters will work in the solution.
- Sun Oct 18, 2020 2:29 pm
- Forum: Student Social/Study Group
- Topic: studying for exams
- Replies: 21
- Views: 2656
Re: studying for exams
I think going over the textbook problems is the best overall way to study as these will be like the questions on the midterm. When it comes closer to the exam I would go over notes, and even though you don't need to memorize equations I would make sure you know when and how to use each one.
- Sun Oct 18, 2020 2:25 pm
- Forum: Limiting Reactant Calculations
- Topic: Difference between limiting reactant and limiting reagent?
- Replies: 14
- Views: 2430
Re: Difference between limiting reactant and limiting reagent?
These terms mean the same thing and are used interchangeably in a question. You calculate them both the same way!
- Sun Oct 18, 2020 2:23 pm
- Forum: Photoelectric Effect
- Topic: photoelectric effect
- Replies: 17
- Views: 853
Re: photoelectric effect
Yes, they are the same thing. They both are the amount of energy required from a wave of light to remove an electron from a metal.
- Fri Oct 09, 2020 2:28 pm
- Forum: Balancing Chemical Reactions
- Topic: State of matter in reaction
- Replies: 9
- Views: 323
Re: State of matter in reaction
The state of matter doesn't affect how you should balance the equation (law of conservation of mass), but it should be written out when writing the equation down.
- Fri Oct 09, 2020 2:21 pm
- Forum: SI Units, Unit Conversions
- Topic: Angstroms
- Replies: 7
- Views: 227
Re: Angstroms
Im guessing that it would just be a capital A, but if not then you could probably write it out (10^-10 m).
- Thu Oct 08, 2020 5:16 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Chemistry Community Grade
- Replies: 12
- Views: 408
Re: Chemistry Community Grade
In order to get these points (maximum 5 points per week), you must post on the chemistry community page, this could be either asking questions or answering other people's questions.
- Thu Oct 08, 2020 5:13 pm
- Forum: Accuracy, Precision, Mole, Other Definitions
- Topic: Textbook question E.1
- Replies: 7
- Views: 287
Re: Textbook question E.1
HI! So first I would change the radius to diameter, so multiply the 144 by 2. Next you need to find how many atoms come in one mole of Ag, and to do that you would multiply 1 mole by 6.02x10^23 (avagadro's constant). When you find out how many atoms, multiply that by 288 pm (the length each atom tak...