Search found 101 matches
- Mon Mar 09, 2020 12:45 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Checking Answers
- Replies: 3
- Views: 352
Re: Checking Answers
I think it's always best to ensure your answer makes sense for the reaction as a method to check too! For example, if we got an order that was an extremely high numbe, something most likely is off
- Mon Mar 09, 2020 12:42 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: 7.9
- Replies: 2
- Views: 255
Re: 7.9
I believe the pseudo first order equation is especially applicable in the lab and helpful in solving for undetermined values regarding a specific reaction
- Mon Mar 09, 2020 12:40 pm
- Forum: Kinetics vs. Thermodynamics Controlling a Reaction
- Topic: Study Advice
- Replies: 73
- Views: 6785
Re: Study Advice
I think going over some of the questions other students have asked on Chem Community is helpful in ensuring you understand every aspect of the topics and maybe help pick up on concepts you missed!
- Mon Mar 09, 2020 12:37 pm
- Forum: General Rate Laws
- Topic: Formula for Individual Reactant Order
- Replies: 1
- Views: 167
Formula for Individual Reactant Order
Is there a specific formula to use to solve for the individual reactant orders when given values in a table such as in 7A.17?
- Mon Mar 09, 2020 12:33 pm
- Forum: *Enzyme Kinetics
- Topic: Catalyst Practice
- Replies: 3
- Views: 266
Catalyst Practice
Does anyone know of a good video or practice problems relating to catalysts?
- Tue Mar 03, 2020 6:49 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6N.1.b
- Replies: 1
- Views: 190
Re: 6N.1.b
I noticed this too... I believe its a solutions manual error
- Tue Mar 03, 2020 2:07 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: lnQ vs logQ
- Replies: 5
- Views: 337
Re: lnQ vs logQ
The logQ is especially helpful if calculating/given the pH!
- Tue Mar 03, 2020 2:06 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Reducing final equation to get n?
- Replies: 2
- Views: 247
Re: Reducing final equation to get n?
I think in that problem, the question didn't require you to use the n value in further steps so it did not matter if you simplified the final equation
- Tue Mar 03, 2020 2:01 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: 6N 9: anode v cathode
- Replies: 2
- Views: 179
Re: 6N 9: anode v cathode
I believe if you treated it as the cathode the Ecell would be negative (which it tells you its a positive 0.061)
- Tue Mar 03, 2020 1:45 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Understanding SHE
- Replies: 2
- Views: 240
Understanding SHE
Hi! I understand that standard cell potentials are based upon references to the SHE model but could some one further explain what exactly the SHE entails?
- Mon Feb 24, 2020 10:33 am
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Nernst
- Replies: 7
- Views: 495
Re: Nernst
When exactly is the cell potential considered at standard conditions?
- Mon Feb 24, 2020 10:24 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell Diagrams
- Replies: 7
- Views: 328
Re: Cell Diagrams
I am confused on this as well, when do we need to introduce Pt into the system?
- Mon Feb 24, 2020 10:14 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Feb 24, 2020 10:14 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Feb 24, 2020 10:13 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Feb 17, 2020 9:19 am
- Forum: Balancing Redox Reactions
- Topic: Helpful Videos
- Replies: 2
- Views: 275
Helpful Videos
Hi! For anyone who learns well off of video tutorials Khan Academy has some great ones for this section! https://www.khanacademy.org/science/che ... -reduction
- Mon Feb 17, 2020 9:18 am
- Forum: Balancing Redox Reactions
- Topic: Possibly helpful: LEO the lion goes GER
- Replies: 2
- Views: 2116
Re: Possibly helpful: LEO the lion goes GER
This is super helpful thank you!
- Mon Feb 17, 2020 9:16 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: When to use the different equations
- Replies: 5
- Views: 390
Re: When to use the different equations
I'm a bit confused about this as well because that delta G equation can also be applied when K is used (the equation is at equilibrium)
- Mon Feb 17, 2020 9:11 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: importance of -RTlnk
- Replies: 7
- Views: 443
Re: importance of -RTlnk
"K is the constant of a certain reaction when it is in equilibrium, while Q is the quotient of activities of products and reactants at any stage of a reaction." Therefore, this equation depicts delta G at equilibrium.
- Mon Feb 17, 2020 9:10 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: sign of delta G
- Replies: 9
- Views: 4192
Re: sign of delta G
When delta G is negative, the reaction is spontaneous and will shift towards the products. When it is positive, the reverse reaction is spontaneous and will shift towards the reactants.
- Mon Feb 17, 2020 9:08 am
- Forum: Administrative Questions and Class Announcements
- Topic: Step Up Sessions
- Replies: 71
- Views: 6759
Re: Step Up Sessions
Hi! Will there still be UA review sessions today despite the holiday?
- Mon Feb 10, 2020 10:04 am
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Extra Practice
- Replies: 4
- Views: 302
Extra Practice
Hi! Does anyone know where to possible find more practice problems regarding applying Le Chatelier's Principle?
- Mon Feb 10, 2020 10:03 am
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 4F.17
- Replies: 1
- Views: 173
Re: 4F.17
I believe you assume you are using one mole in the reaction
- Mon Feb 10, 2020 10:01 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: spontaneity
- Replies: 18
- Views: 682
Re: spontaneity
What is the significance of whether or not a reaction is spontaneous? How do we apply this is real-world situations?
- Mon Feb 10, 2020 9:59 am
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: standard entropy meaning
- Replies: 3
- Views: 188
Re: standard entropy meaning
The naught above the S indicates standard state.
- Mon Feb 10, 2020 9:55 am
- Forum: Administrative Questions and Class Announcements
- Topic: Step Up Sessions
- Replies: 71
- Views: 6759
Re: Step Up Sessions
Hi does anyone know if Lyndon's workshop is still happening tonight?
- Mon Feb 03, 2020 7:17 am
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: q vs H
- Replies: 9
- Views: 457
Re: q vs H
Are deltaH and q interchangeable?
- Mon Feb 03, 2020 7:15 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Reversible/ Irreversible Expansion
- Replies: 3
- Views: 110
Re: Reversible/ Irreversible Expansion
Would the problems always specify whether it's reversible or irreversible? If not, how can we assume?
- Mon Feb 03, 2020 7:13 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: 4A.9
- Replies: 2
- Views: 88
Re: 4A.9
Also it says that no heat is lost to surroundings so we can assume that heat moves out of the copper and into the water, eventually making their temperatures equal to one another.
- Mon Feb 03, 2020 7:10 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: 4B.5
- Replies: 3
- Views: 120
Re: 4B.5
In this case would it be necessary to convert the pressure from Torr to atm before plugging it into the equation?
- Mon Feb 03, 2020 7:07 am
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Sig figs and calorimetry example
- Replies: 2
- Views: 97
Re: Sig figs and calorimetry example
I believe in this example he was more emphasizing the process of solving those type of problems and wanted to show us accurate calculations (before sig fig rounding)
- Mon Jan 27, 2020 2:55 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Jan 27, 2020 2:54 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Jan 27, 2020 2:51 pm
- Forum: Phase Changes & Related Calculations
- Topic: Chem 14A Final Pickup
- Replies: 8
- Views: 340
Re: Chem 14A Final Pickup
Does anyone know where and when we can pick them up?
- Mon Jan 27, 2020 2:49 pm
- Forum: Phase Changes & Related Calculations
- Topic: ∆H
- Replies: 17
- Views: 618
Re: ∆H
There are some instances where you can assume without the actual value such as when you break a bond (endothermic as energy is required to break the bond)
- Mon Jan 27, 2020 2:39 pm
- Forum: Phase Changes & Related Calculations
- Topic: phase changes
- Replies: 5
- Views: 128
Re: phase changes
I am a bit confused on this topic. Could someone please use an example of how phase changes are taken into account?
- Mon Jan 20, 2020 4:37 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Jan 20, 2020 4:36 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Salt Solutions
- Replies: 3
- Views: 121
Re: Salt Solutions
Hi! I found this video to be very useful on this topic. https://www.khanacademy.org/science/che ... -solutions
- Mon Jan 20, 2020 4:30 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 2
- Views: 147
Re: Le Chatelier's Principle
Also, if the moles of gas on either side of the reaction (and therefore space taken up in the volume) are equal than a change in pressure has no effect
- Mon Jan 20, 2020 4:28 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Summary of Le Chatelier
- Replies: 5
- Views: 301
Re: Summary of Le Chatelier
This is a great summary of the concept! https://www.khanacademy.org/science/che ... -principle
- Mon Jan 20, 2020 4:27 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Endothermic Reactions
- Replies: 4
- Views: 210
Re: Endothermic Reactions
However, remember that if the reaction is a exothermic reaction, adding heat will result in the formation of reactants
- Mon Jan 13, 2020 2:12 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: 5I.13
- Replies: 4
- Views: 1064
Re: 5I.13
Hi this is a pretty involved question and I was confused at first as well but the step by step solution in the Solutions Manual was really helpful!
- Mon Jan 13, 2020 2:09 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Practice Problems
- Replies: 4
- Views: 448
Re: Practice Problems
I found this worksheet online too which can give you a couple more practice problems on the topic. http://mmsphyschem.com/lechatP.pdf
- Mon Jan 13, 2020 2:08 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Increase pressure by half the volume
- Replies: 3
- Views: 114
Re: Increase pressure by half the volume
This is true however remember that the actual equilibrium ratio remains the same. Only temperature can change K. :)
- Mon Jan 13, 2020 2:07 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: "Quick way" part in Lecture
- Replies: 7
- Views: 176
Re: "Quick way" part in Lecture
I am also a bit confused on this topic. Can someone please explain the difference between the quick way and the actual reasoning to solve these types of problems? Thanks
- Mon Jan 13, 2020 2:05 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Textbook question 5J.11
- Replies: 3
- Views: 168
Re: Textbook question 5J.11
Yes! Because it involves the breaking of the bond between the two X molecules to form two separated X molecules we know that energy aka heat had to be put into the reaction to overcome the bond energy. Therefore it is endothermic.
- Mon Jan 06, 2020 2:39 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Determining Equilibrium Reaction Direction
- Replies: 4
- Views: 159
Re: Determining Equilibrium Reaction Direction
So would anything between k > 10^3 and k > 1 be only slight favoring?
- Mon Jan 06, 2020 2:34 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Jan 06, 2020 2:33 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Jan 06, 2020 2:30 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Self Test 5G.3A
- Replies: 4
- Views: 130
Self Test 5G.3A
Write the equilibrium constant fir the reaction 2 AgNO3 (aq) + 2NaOH (aq)-----> Ag2O (s) + 2NaNO3 (aq) + H2O (l)
I'm a bit confused as to how to take the net ionic equation into account. Thanks!
I'm a bit confused as to how to take the net ionic equation into account. Thanks!
- Mon Jan 06, 2020 2:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Question 5G
- Replies: 3
- Views: 623
Re: Question 5G
If you are referring to 5G.1 part c, they aren't asking you to calculate the partial pressure but rather want you to state that the statement is false. Equilibrium reactions are affected by the presence of both products and reactants.
- Mon Dec 02, 2019 12:14 pm
- Forum: Calculating the pH of Salt Solutions
- Topic: 6D.11 c and d
- Replies: 1
- Views: 147
Re: 6D.11 c and d
I believe that book sometimes does it differently and keeps the halogens in the equations either way but I was confused about this too.
- Mon Dec 02, 2019 12:12 pm
- Forum: Polyprotic Acids & Bases
- Topic: Section 6E.1
- Replies: 2
- Views: 132
Re: Section 6E.1
I believe so and I think he wanted us to heavily focus on the description box 6E.1 in particular
- Mon Dec 02, 2019 12:10 pm
- Forum: Polyprotic Acids & Bases
- Topic: Chelates Visual
- Replies: 2
- Views: 282
Chelates Visual
Does anyone know of any helpful videos or images to help me picture how chelates function? Thanks!
- Mon Dec 02, 2019 12:08 pm
- Forum: Amphoteric Compounds
- Topic: amphiprotic and amphoteric
- Replies: 9
- Views: 693
Re: amphiprotic and amphoteric
An analogy that helped me was that of a rectangle and a square.... a square is always a rectangle but a rectangle isn't always a square. The same goes for these terms as amphiprotic is always amphoteric but amphoteric molecules are not always amphiprotic
- Mon Dec 02, 2019 11:58 am
- Forum: Bronsted Acids & Bases
- Topic: 6.5
- Replies: 1
- Views: 87
6.5
How can you tell which is the base and which is the acid in the formula:
H2O2 + SO3 -----> H2SO5
I tried drawing lewis structures but still don't quite understand. Thanks!
H2O2 + SO3 -----> H2SO5
I tried drawing lewis structures but still don't quite understand. Thanks!
- Mon Nov 25, 2019 9:25 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: coordination sphere
- Replies: 3
- Views: 217
Re: coordination sphere
I understand the concept of a coordination sphere but am a bit unsure of how to identify a ligand versus other molecules that would not be included. Can someone explain this is detail please? Thanks!
- Mon Nov 25, 2019 9:22 am
- Forum: Naming
- Topic: Naming Help
- Replies: 1
- Views: 140
Naming Help
Has anyone seen any helpful videos to explain/help memorize how to name compounds? Thanks!
- Mon Nov 25, 2019 9:22 am
- Forum: Naming
- Topic: Coordination shape
- Replies: 3
- Views: 125
Re: Coordination shape
I believe you would need more information to identify exactly which shape it is such as hybridization or specific numbers of lone pairs/bonding pairs
- Mon Nov 25, 2019 9:20 am
- Forum: Industrial Examples
- Topic: Favorite Industrial Example
- Replies: 3
- Views: 1108
Re: Favorite Industrial Example
As someone stated previously, I think bismuth subsalicylate, or Pepto-Bismol, is an example of an industrial coordination compound.
- Mon Nov 25, 2019 9:19 am
- Forum: Biological Examples
- Topic: Porphyrin ligand-tetradentate
- Replies: 2
- Views: 324
Re: Porphyrin ligand-tetradentate
Here's what I gathered...
- it is an example of a cage-like molecule
- it is square planar
- Fe is bound to the porphyrin ligand to form a heme complex
- the heme complex plus a protein creates myoglobin (Fe binds to 1 O2)
- it plays a role in the transport of O2 in the muscle cells
- it is an example of a cage-like molecule
- it is square planar
- Fe is bound to the porphyrin ligand to form a heme complex
- the heme complex plus a protein creates myoglobin (Fe binds to 1 O2)
- it plays a role in the transport of O2 in the muscle cells
- Wed Nov 20, 2019 9:13 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: HW 2F:21a
- Replies: 2
- Views: 176
Re: HW 2F:21a
the shape will be trigonal planar around each C atom
- Wed Nov 20, 2019 9:12 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2.45 Homework Question
- Replies: 1
- Views: 138
- Wed Nov 20, 2019 9:09 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Resonance and Rotation
- Replies: 1
- Views: 151
Resonance and Rotation
If a molecule has resonance (some double bonds and some single bonds) and therefore a few pi bonds can any of the atoms rotate?
- Wed Nov 20, 2019 9:04 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2E.13 part a
- Replies: 3
- Views: 241
Re: 2E.13 part a
If a molecule has two bond pairs and 3 lone pairs (AX2E3) it is linear in shape and therefore has a bond angle of 180 degrees.
- Wed Nov 20, 2019 9:03 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Lone Pairs for AX4E
- Replies: 3
- Views: 181
Re: Lone Pairs for AX4E
The lone pairs are placed based on repulsion strengths:
lone pr-lone pr>lone pr-bond pr>bond pr-bond pr
Therefore, by placing the lone pair on the equatorial plane, it allows for repulsion strengths to play out
lone pr-lone pr>lone pr-bond pr>bond pr-bond pr
Therefore, by placing the lone pair on the equatorial plane, it allows for repulsion strengths to play out
- Tue Nov 12, 2019 10:00 am
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Tue Nov 12, 2019 9:58 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Simpler Terms
- Replies: 4
- Views: 722
Re: Simpler Terms
I found this Khan Academy video to be really helpful on explaining this topic! https://www.khanacademy.org/science/che ... amagnetism
- Tue Nov 12, 2019 9:57 am
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: bond order
- Replies: 4
- Views: 463
Re: bond order
Hi! I found this link to be very helpful in explaining the topic: https://chem.libretexts.org/Bookshelves ... _Chemistry)/Chemical_Bonding/Fundamentals_of_Chemical_Bonding/Bond_Order_and_Lengths
- Tue Nov 12, 2019 9:52 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Memorization Tips
- Replies: 3
- Views: 333
Re: Memorization Tips
Not sure where this quizlet is from but it was really helpful for me to memorize! https://quizlet.com/291777131/vsepr-shapes-flash-cards/
- Tue Nov 12, 2019 9:50 am
- Forum: Hybridization
- Topic: Hybridization Models
- Replies: 4
- Views: 438
Re: Hybridization Models
This video was really helpful for me to visualize. https://www.youtube.com/watch?v=vHXViZTxLXo
- Wed Nov 06, 2019 9:37 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Accessing the E-textbook [ENDORSED]
- Replies: 125
- Views: 29715
Re: Accessing the E-textbook [ENDORSED]
If anyone has any issues opening the Sapling after purchasing it from the UCLA bookstore I called the company and it was really helpful. I just had to send a picture of my receipt and etext code and they registered my account for the class.
- Wed Nov 06, 2019 9:34 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Wed Nov 06, 2019 9:30 pm
- Forum: Bond Lengths & Energies
- Topic: Test 2 Topics
- Replies: 40
- Views: 2066
Test 2 Topics
Does anyone know if test 2 is cumulative or just the topics covered from the midterm to the test? Thanks!
- Wed Nov 06, 2019 9:28 pm
- Forum: Bond Lengths & Energies
- Topic: Midterm
- Replies: 9
- Views: 478
Re: Midterm
In class he suggested about a week but given it's all free response it may take longer
- Wed Nov 06, 2019 9:26 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3013715
- Mon Oct 28, 2019 9:36 am
- Forum: Quantum Numbers and The H-Atom
- Topic: H atom
- Replies: 3
- Views: 129
Re: H atom
I think it also has to do with that H is the most common element. It has several uses and forms cations very easily.
- Mon Oct 28, 2019 9:33 am
- Forum: Quantum Numbers and The H-Atom
- Topic: 1D.17
- Replies: 3
- Views: 190
Re: 1D.17
-1, 0, 1
-2, -1, 0, 1, 2
-1, 0, 1
-3, -2, -1, 0, 1, 2, 3
-2, -1, 0, 1, 2
-1, 0, 1
-3, -2, -1, 0, 1, 2, 3
- Mon Oct 28, 2019 9:29 am
- Forum: Properties of Light
- Topic: 1.31
- Replies: 4
- Views: 207
Re: 1.31
Could someone please explain part a as well please? I am confused about this question.
- Mon Oct 28, 2019 9:26 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1E.25
- Replies: 1
- Views: 166
1E.25
Give the notation for the valence shell configuration (including the outermost d-electrons) of (a) the alkali metals; (b) Group 15 elements (c) Group 5 transition metals (d) the "coinage" metals (Cu, Ag, Au).
- Mon Oct 28, 2019 9:21 am
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1E.15
- Replies: 2
- Views: 178
Re: 1E.15
I was confused about this too. I thought we were supposed to switch the 4s and 3d orbitals when writing out the configuration. Why is it 3d then 4s in the book? Must the 3d be filled to switch back to before the 4s? Thanks.
- Mon Oct 21, 2019 10:48 pm
- Forum: Trends in The Periodic Table
- Topic: Metals, Nonmetals, Metalloids
- Replies: 5
- Views: 448
Metals, Nonmetals, Metalloids
Hi, does anyone know if we must memorize which elements are metals, nonmetals, and metalloids or will it be indicated on the periodic table given to us? If so, are there any tips to memorizing which is which? Thanks!
- Mon Oct 21, 2019 10:46 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1E.25
- Replies: 3
- Views: 191
1E.25
Give the notation for the valence-shell configuration (including the outermost d-electrons) of (a) the alkali metals (b) Group 15 elements (c) Group 5 transition metals (d) the "coinage" metals (Cu, Ag, Au)
- Mon Oct 21, 2019 10:44 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 1E.23
- Replies: 2
- Views: 188
1E.23
The elements Ga, Ge, As, Se, and Br lie in the same period in the periodic table. Write the electron configuration expected from the ground-state atoms of these elements and predict how many unpaired electrons, if any, each atom has.
- Mon Oct 21, 2019 8:35 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: 4s before 3d
- Replies: 4
- Views: 220
Re: 4s before 3d
Hi here's a diagram of Aufbau's Principle, hope this helps clarify!
- Mon Oct 21, 2019 8:30 pm
- Forum: Trends in The Periodic Table
- Topic: Electron Affinity Trends
- Replies: 5
- Views: 586
Re: Electron Affinity Trends
Electron affinity decreases down the groups and increases across the periods because the electrons added are closer to the nucleus creating a stronger attraction and tighter hold.
- Tue Oct 15, 2019 7:12 pm
- Forum: Heisenberg Indeterminacy (Uncertainty) Equation
- Topic: *Lowest possible energy?
- Replies: 2
- Views: 87
Re: *Lowest possible energy?
Because the momentum and position are uncertain, the energy may be uncertain as well. Sometimes, the window of uncertainty is given and you could use the lowest value in this region to calculate the approximate lowest energy level.
- Tue Oct 15, 2019 7:08 pm
- Forum: Properties of Electrons
- Topic: Question about diffraction patterns
- Replies: 3
- Views: 268
Re: Question about diffraction patterns
I hope this image helps clarify as well!
- Tue Oct 15, 2019 7:06 pm
- Forum: Properties of Light
- Topic: What units do we need to use for the Rydberg constant?
- Replies: 2
- Views: 97
Re: What units do we need to use for the Rydberg constant?
Both of these Rydberg constants are equal and vary just because of their units.
for E=-hR/n^2.... 3.28984 * 10^15 Hz should be used and that is what is given on the formula sheet
for E=-hR/n^2.... 3.28984 * 10^15 Hz should be used and that is what is given on the formula sheet
- Tue Oct 15, 2019 7:00 pm
- Forum: Photoelectric Effect
- Topic: Wavelength Emitted
- Replies: 4
- Views: 237
Wavelength Emitted
Will there always be a positive wavelength of light emitted with e- transitions no matter if it's moving up or down energy levels?
- Tue Oct 15, 2019 5:24 pm
- Forum: Photoelectric Effect
- Topic: Module Question
- Replies: 2
- Views: 1256
Module Question
In 1.0s, a 60 W bulb emits 11 J of energy in the form of infrared radiation (heat) of wavelength 1850 nm. What is the energy per photon of light emitted? How many photons of infrared radiation does the lamp generate in1.0s?
- Sat Oct 12, 2019 3:01 pm
- Forum: Properties of Light
- Topic: What exactly is diffraction?
- Replies: 3
- Views: 164
Re: What exactly is diffraction?
Hi! I was a bit confused about this topic as well and found this video to be really clear! Hope this helps. https://www.youtube.com/watch?v=1bHipDSHVG4
- Sat Oct 12, 2019 2:58 pm
- Forum: Properties of Light
- Topic: Constructive & Destructive
- Replies: 4
- Views: 111
Re: Constructive & Destructive
Yes this is possible. However, they would have to have the exact same wavelength and frequency.
- Sat Oct 12, 2019 12:55 pm
- Forum: Properties of Light
- Topic: Quanta vs Photon
- Replies: 4
- Views: 146
Re: Quanta vs Photon
Quantized objects have a discrete numerical value. For example, an electron cannot jump energy levels without having exactly the amount of energy needed to move (no more no less). Because there is no halfway point, it is quantized.
- Sat Oct 12, 2019 12:43 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect diagram
- Replies: 3
- Views: 263
Re: Photoelectric Effect diagram
The information the detector picks up tells us about the energy of the electron (if they are emitted) and therefore can reveal important traits of the metal and/or light source.
- Fri Oct 11, 2019 7:45 pm
- Forum: Photoelectric Effect
- Topic: Module Post Assessment 33
- Replies: 1
- Views: 85
Module Post Assessment 33
Molybdenum metal must absorb radiation with a minimum frequency of 1.09 x 10^15 s^-1 before it can emit an electron from its surface. Answer the following two questions. A. What is the minimum energy needed to produce this effect? B. If molybdenum is irradiated with 194 nm light, what is the maximum...
- Sat Sep 28, 2019 5:57 pm
- Forum: Molarity, Solutions, Dilutions
- Topic: G.13
- Replies: 3
- Views: 178
Re: G.13
Hi! I was confused about this at first as well but my TA explained that since you are looking for the specific number of moles of nitrogen atoms each plant will receive, you need to relate the final mole amount to the amount of N moles in the original compound. Since the compound NH4NO3 has 2 nitrog...
- Sat Sep 28, 2019 3:42 pm
- Forum: Limiting Reactant Calculations
- Topic: Homework Problem M.7 (b)
- Replies: 2
- Views: 164
Homework Problem M.7 (b)
Solid boron can be extracted from soli boron oxide by reaction with magnesium metal at a high temperature. A second product is solid magnesium oxide. (b) What mass of boron can be produced when 1.25kg or boron oxide is heated with 125kg of magnesium? I converted the kg to g and then solved for the m...
- Sat Sep 28, 2019 11:25 am
- Forum: SI Units, Unit Conversions
- Topic: Nomenclature
- Replies: 4
- Views: 319
Nomenclature
Hi! I wasn't sure which topic to place this under and figured this was closest to general chemistry basics.... does anyone have any tips on help with nomenclature? I do not have a strong background in chemistry and am looking for some help with understanding the compound names etc. Thanks!
- Sat Sep 28, 2019 10:57 am
- Forum: Molarity, Solutions, Dilutions
- Topic: Homework Problem G.21 [ENDORSED]
- Replies: 2
- Views: 289
Homework Problem G.21 [ENDORSED]
A solution is prepared by dissolving 0.500g of KCl, 0.500g of K2S, and 0.500g of K3PO4 in 500mL of water. What is the concentration in the final solution of (a) potassium ions; (b) sulfide ions? Would it be appropriate to group the compounds and their masses together at the beginning of the problem ...