Search found 107 matches
- Fri Mar 12, 2021 11:56 pm
- Forum: General Rate Laws
- Topic: Sapling Week 9/10 #13
- Replies: 5
- Views: 322
Sapling Week 9/10 #13
I understand the basics of rate reactions. But how do i solve for a rate law with multiple equations? The mechanism proposed for the oxidation of iodide ion, I−, by the hypochlorite ion, ClO−, in aqueous solution is shown. ClO−(aq)+H2O(l)⇌HClO(aq)+OH−(aq)fast in both directions I−(aq)+HClO(aq)→HIO(a...
- Sun Mar 07, 2021 11:51 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Sapling Week 5/6 #15
- Replies: 2
- Views: 293
Sapling Week 5/6 #15
Could someone help me through the proper steps because every time i tried this I couldn't get it right. I know its old but i'm re studying and was wondering if anyone could help. Anything would be appreciated! Given the information A+B⟶2D ΔH∘=−720.9 kJ ΔS∘=311.0 J/K C⟶D ΔH∘=466.0 kJ ΔS∘=−214.0 J/K c...
- Sun Mar 07, 2021 11:45 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K
- Replies: 33
- Views: 1508
Re: K
Kc is a more specific version of K. K is an equilibrium constant. Kc is the equilibrium constant for molar concentrations. Kp is equilibrium constant for pressure.
- Sun Mar 07, 2021 11:44 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: DeltaU Equation
- Replies: 2
- Views: 218
Re: DeltaU Equation
i sadly dont believe there is! I just wrote them all down in a page of my notebook. But most of them are just versions of each other so not too bad
- Sun Mar 07, 2021 11:39 pm
- Forum: Ideal Gases
- Topic: K and Q
- Replies: 57
- Views: 3761
Re: K and Q
So K is the equilibrium constant. Q is the reaction quotient because it can occur at any point of time during the equation. If Q=K, that meaNs the equation is at equilibrium.
- Sun Mar 07, 2021 11:36 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Sapling Week 5/6 #7
- Replies: 2
- Views: 390
Sapling Week 5/6 #7
Hi! I know this is an old question from a couple of weeks ago but i was wondering if anyone could help me solve for #7? Im confused about the heat of vaportization and what equation to use. Any help would be appreciated! Three liquid samples of known masses are heated to their boiling points with th...
- Sun Feb 28, 2021 11:56 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sapling Week 7/8 #15
- Replies: 11
- Views: 715
Re: Sapling Week 7/8 #15
Hi! To solve this equation we can break it down into the parts that we will need for it. You have the right E values, so all you need to do is the E(cathode)-E(anode) to get our Eº for the equation. This should look something like (-.14)-(-.76), since you already have these values and we know the m...
- Sun Feb 28, 2021 11:41 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sapling Week 7/8 #15
- Replies: 11
- Views: 715
Re: Sapling Week 7/8 #15
Yeah! So, with this one, you'd want to use the Nernst equation E=Edot-0.05916V/nlogQ to solve. But, to get Edot, you'd use Ecell=Ecathode-Eanode, to find Ecell of the overall reaction. From there you can apply Nernst equation to solve for E or the cell potential. This may be a dumb question. But ho...
- Sun Feb 28, 2021 11:34 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sapling Week 7/8 #15
- Replies: 11
- Views: 715
Sapling Week 7/8 #15
Could someone help me start this problem? Calculate the cell potential for the reaction as written at 25.00 °C , given that [Zn2+]=0.829 M and [Sn2+]=0.0130 M . Use the standard reduction potentials in this table. Zn(s)+Sn2+(aq)↽−−⇀ Zn2+(aq)+Sn(s) Zn=-0.76 Sn=-0.14 Im confused on the steps so any st...
- Sun Feb 28, 2021 11:31 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sapling Week 7/8 #12
- Replies: 5
- Views: 431
Re: Sapling Week 7/8 #12
Audrey Han 3L wrote:If you have all the number of electrons right and the standard potential, then make sure your answer is in kJ rather than joules
Oh! I hadnt seen this. Thank you! That got me the right answer
- Sun Feb 28, 2021 11:27 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sapling Week 7 and 8 #7
- Replies: 11
- Views: 535
Re: Sapling Week 7 and 8 #7
Shanna Yu 1C wrote:Hi!
Yeah, the stuff in the line diagram needs to be in a specific order:
Pb, PbCl2, Cl, then Cl, AgCl, Ag, in that order.
Thank you I appreciated this. I was mixing things up so this was straight forward and I appreciate it.
- Sun Feb 28, 2021 11:22 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Sapling Week 7/8 #12
- Replies: 5
- Views: 431
Sapling Week 7/8 #12
HI Could someone help me!
Calculate the standard free-energy change for the reaction at 25 ∘C.
Refer to the list of standard reduction potentials.
2Au3+(aq) + 3Zn(s)↽−−⇀2Au(s) + 3Zn2+(aq)
Au=1.5
Zn=-0.76
Im stuck here! I know the equation is delta G=-nFE but I could use some help. Thank you!
Calculate the standard free-energy change for the reaction at 25 ∘C.
Refer to the list of standard reduction potentials.
2Au3+(aq) + 3Zn(s)↽−−⇀2Au(s) + 3Zn2+(aq)
Au=1.5
Zn=-0.76
Im stuck here! I know the equation is delta G=-nFE but I could use some help. Thank you!
- Sun Feb 28, 2021 11:08 pm
- Forum: Balancing Redox Reactions
- Topic: Sapling week 7/8 #18
- Replies: 25
- Views: 5144
Re: Sapling week 7/8 #18
Thank you this helps alot! I have been stumped
- Sun Feb 21, 2021 10:01 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Sapling 5/6 #9
- Replies: 4
- Views: 1163
Re: Sapling 5/6 #9
The change in entropy of the system is given by ΔS∘sys=∑S∘(products)−∑S∘(reactants) where S∘ is the standard entropy. The change in entropy of the surroundings is given by ΔSsurr=−ΔHsysT The change in entropy of the universe is the sum of the change in entropy of the system and the change in entrop...
- Sun Feb 21, 2021 9:59 pm
- Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
- Topic: Sapling 5/6 #7
- Replies: 2
- Views: 200
Sapling 5/6 #7
Hi! I need alittle help starting this problem. Three liquid samples of known masses are heated to their boiling points with the use of a heater rated at 525.0 W . Once the boiling points of each sample are reached, the samples are heated for an additional 6.88 min , which results in the vaporization...
- Sun Feb 21, 2021 9:56 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: qrev
- Replies: 27
- Views: 1708
Re: qrev
qrev is the heat generated in a reversible process. the rev represents reversible.
- Sun Feb 21, 2021 9:53 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: K vs. Kc
- Replies: 36
- Views: 1495
Re: K vs. Kc
They both are the same thing! However Kc is a more specific term. It specifically is for concentrations. Kp is for pressures. And K is an umbrella term. But they are all solved the same way!
- Sun Feb 21, 2021 9:50 pm
- Forum: Ideal Gases
- Topic: Temperature
- Replies: 99
- Views: 7775
Re: Temperature
Yes! You assume its 25C or 298K.
- Sun Feb 14, 2021 7:06 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Sapling 5/6 #9
- Replies: 4
- Views: 1163
Sapling 5/6 #9
Hi! I need a little help with the following. Consider the following reaction at 298 K. C(graphite)+2H2(g)⟶CH4(g) ΔH∘=−74.6 kJ Calculate the following quantities. Refer to the standard entropy values as needed. I understand how to calculate the entropy of the system but I am confused with how to find...
- Sun Feb 14, 2021 6:01 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: W5/6 Sapling #6
- Replies: 6
- Views: 531
Re: W5/6 Sapling #6
Don't forget to convert Cvm to Cv! The moles of neon is given to you can multiply moles by Cvm to get Cv then use that for the change in entropy equation with temperature. Add the two values from both equations to get final answer. Thank you! Ive been so stumped because I haven't not been able to u...
- Sun Feb 14, 2021 5:42 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Spaling 5/6 #6
- Replies: 6
- Views: 394
Re: Spaling 5/6 #6
JonathanM wrote:Hey! so the problem tells you at the beginning that there are 4.63 moles of the neon gas. Hope this helps!
So how do I get J/K from J/(mol*k)? If you multiply them i get 78.06 and that is not the correct answer. How do I correctly get there?
- Sun Feb 14, 2021 4:53 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Spaling 5/6 #6
- Replies: 6
- Views: 394
Re: Spaling 5/6 #6
Gabby Magat 3F wrote:I think Jonathan's answer sums it up, you just want to make sure that your final answer is in J/K rather than J/(mol*K)!
This may be a dumb question, but how do I convert to that? This is where I'm stumped.
- Sun Feb 14, 2021 4:34 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Spaling 5/6 #6
- Replies: 6
- Views: 394
Spaling 5/6 #6
Hi. I was hoping someone could help me figure out what I am doing wrong for this problem. A particular container holds 4.63 mol of neon gas. The volume of this container can be altered by sliding a piston in or out. The volume is changed from 7.50 L to 5.30 L while at the same time the temperature i...
- Sun Feb 07, 2021 11:48 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling week 3&4 #14
- Replies: 3
- Views: 250
Re: Sapling week 3&4 #14
Hi! So the steps you commented about knowing how to do (using the PV=nRT and w=-nRTln(Vf/Vi) will give you your answer for part A. Then, for part B, the process occurs in two steps, so the work done by path B is a sum of the work in each step. The work done in these steps is calculated using w=-P(d...
- Sun Feb 07, 2021 11:47 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling #18
- Replies: 2
- Views: 211
Re: Sapling #18
Hi! 1. So first you solve for Cp. You calculate Cp by whatever equation they give you. Mine was 5/2*R. 2. Then you solve for q, which the equation is q=n*Cp*ΔT. You should be given n in the problem. It will say mols after the number. 3. Then you calculate Cv. Cv=Cp-R 4. Then you solve for U. which y...
- Sun Feb 07, 2021 11:37 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling week 3&4 #14
- Replies: 3
- Views: 250
Sapling week 3&4 #14
Hi. Im little lost on how to do this problem. Any help would be amazing! A sample of an ideal gas in a cylinder of volume 4.21 L at 298 K and 2.33 atm expands to 8.97 L by two different pathways. Path A is an isothermal, reversible expansion. Path B has two steps. In the first step, the gas is coole...
- Sun Feb 07, 2021 10:43 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling week 3&4 #10
- Replies: 3
- Views: 235
Re: Sapling week 3&4 #10
Stuti Pradhan 2J wrote:I expanded out your work so the equation is
17076 + 214.22 Tf = -1870 Tf + 84161
and I seem to be getting the right answer.
There was probably just a math error somewhere.
Hope this helps!
Thank you so much! It was just a math error. But that helped!
- Sun Feb 07, 2021 10:40 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Wks 3 & 4 Sapling Q18
- Replies: 6
- Views: 393
Re: Wks 3 & 4 Sapling Q18
This was very helpful! Thank you for the step by step help.
- Sun Feb 07, 2021 10:32 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Sapling week 3&4 #10
- Replies: 3
- Views: 235
Sapling week 3&4 #10
Hi. Ive tried to do #12 a couple times and I can't not get the write answer. Could someone help explain the process? An ice cube with a mass of 51.2 g at 0.0 ∘C is added to a glass containing 447 g of water at 45.0 ∘C. Determine the final temperature of the system at equilibrium. The specific heat c...
- Sun Jan 31, 2021 10:43 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Work
- Replies: 7
- Views: 316
Re: Work
Work is negative if the system is losing energy! The energy is transferred to the surrounding so it’s “lost” and thus is negative. Work is positive if the system has energy going into it. I usually remember it as work as heat, it’s a good example. If the system is losing heat, it’s putting heat into...
- Sun Jan 31, 2021 10:38 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Would an aq agent be included in K?
- Replies: 27
- Views: 1121
Re: Would an aq agent be included in K?
Yes aqueous solutions would be included for Kc! They would not however for Kp because partial pressures are gases. But yes for Kc;because they’re liquids and affect concentrations.
- Sun Jan 31, 2021 10:36 pm
- Forum: Ideal Gases
- Topic: Outline 1 PV = nRT
- Replies: 4
- Views: 155
Re: Outline 1 PV = nRT
Exactly. This is to just include gases. Liquids and solids can not be used for this equation. You also need to make sure you have the parts of PV=nRT. So you need 3 of the 4: pressure, temperature, volume, and number of moles. This is an approximation because it’s on “ideal” gases.
- Sun Jan 31, 2021 10:32 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: pKa and pH
- Replies: 6
- Views: 266
Re: pKa and pH
In chem, the lowercase p seems to represent the -log. As stated above, pKa is equal to the -log of Ka. The pH is -log of the concentrations of [H3O+]. The smaller the pKa is the stronger the acid is. As to tell the strength of the acid, the lower the pH, the stronger the acid. So the lower the pKa a...
- Sun Jan 31, 2021 10:24 pm
- Forum: Ideal Gases
- Topic: Conditions
- Replies: 20
- Views: 1603
Re: Conditions
The standard temperature and pressure would be 273K, which is equal to 0 degrees Celsius, and 1 atmosphere.
- Sun Jan 24, 2021 11:33 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Sapling Week 2 #5
- Replies: 3
- Views: 223
Re: Sapling Week 2 #5
The way I did it was to first find the pOH (14-pH), then find the concentration of the -OH by using 10^-pOH. This will act as the X in the ICE table Next, we can solve for our missing/needed value by setting up the equation Kb=[BH][OH]/[B] where be is our original base and BH is its conjugate acid,...
- Sun Jan 24, 2021 11:28 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Number 5
- Replies: 18
- Views: 712
Re: Sapling Number 5
Yeprem wrote:I completely forgot to add [B] with [BH+] to find the [B] formal:(
Thank you
Thanks for clarifying this! I have been stuck on this for so long. This helped make it clear what B formal is!
- Sun Jan 24, 2021 11:25 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Clarification for Sampling #7
- Replies: 10
- Views: 593
Re: Clarification for Sampling #7
Yep! A general rule is if its an acid use Ka, and if its a base use Kb. And to convert between the two you can use this equation Ka x Kb = 1 x 10^-14! Hope that helps!
- Sun Jan 24, 2021 11:22 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Sapling 9
- Replies: 10
- Views: 405
Re: Sapling 9
If the pH goes below pKa, that means the acidity of the solution becomes stronger than the pKa. When this occurs, the protonated species of HA will become more predominant, HA becomes neutral and A- is charged.
- Sun Jan 24, 2021 11:17 pm
- Forum: Ideal Gases
- Topic: How can we identify when to use the ideal gas law?
- Replies: 11
- Views: 701
Re: How can we identify when to use the ideal gas law?
I recommend looking at the problem and see what units you are given, with any problem given for any test! And if the units happen to include pressure, temperature, volume, or moles, then the Ideal Gas Law will probably be the equation for you to use to find the missing variable!
- Sun Jan 24, 2021 11:14 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Sapling Week 2 #5
- Replies: 3
- Views: 223
Sapling Week 2 #5
Hi! I was wondering if someone could double check my work because I can not seem to get the correct answer! Here is my problem: The Kb for an amine is 3.107×10−5. What percentage of the amine is protonated if the pH of a solution of the amine is 9.128 ? Assume that all OH− came from the reaction of ...
- Sun Jan 17, 2021 10:26 pm
- Forum: Ideal Gases
- Topic: Sapling Question #4
- Replies: 11
- Views: 580
Re: Sapling Question #4
Hi! Its so bad once you think it through. First I always set up a partial pressures. Then make an ice chart and then plug everything back into the partial pressure equation! Kp=[pPCl5]/[pPCl3][pCl2] ice PCl3 + Cl2 --- PCl5 i 0 0 0.025 c +x +x -x e x. x. 0.025-x Kp=[0.025-x]/[x][x]=399 And solve from...
- Sun Jan 17, 2021 10:18 pm
- Forum: Ideal Gases
- Topic: Kp?
- Replies: 30
- Views: 1125
Re: Kp?
Partial Pressures are only for gases in this course!
- Sun Jan 17, 2021 10:10 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Week 1 #9
- Replies: 3
- Views: 217
Re: Sapling Week 1 #9
I figured my error out! thanks tho!
- Sun Jan 17, 2021 10:08 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Week 1 #9
- Replies: 3
- Views: 217
Sapling Week 1 #9
For question 9, I cant get the right answer no matter how hard I try. Here is the problem and my values? At equilibrium, the concentrations in this system were found to be [N2]=[O2]=0.100 M and [NO]=0.600 M. N2(g)+O2(g)↽−−⇀2NO(g) If more NO is added, bringing its concentration to 0.900 M, what will ...
- Sun Jan 17, 2021 9:36 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Reactants and Products
- Replies: 9
- Views: 445
Re: Reactants and Products
Yes! if that how the equation is written, thats how they will be discussed. But with many of these equilibrium equations, you can write the equations either way, but will need to pay attention to K, Q, and other values that will change if you switch directions. Hope that helps!
- Sun Jan 17, 2021 9:33 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Sapling Week 1 #5
- Replies: 8
- Views: 617
Sapling Week 1 #5
For question 5, I understand how to cancel all the equations and convert the k values. But how do we combine the k values for the total K? I used equations Ka and Kc and was able to convert them but how to you combine the two new k values? And tips would be appreciated!
- Sun Jan 10, 2021 11:26 pm
- Forum: Ideal Gases
- Topic: Gas constant R
- Replies: 26
- Views: 1351
Re: Gas constant R
The gas constant is a constant. So any time a constant is mentioned it means it will always be the same specific number. An similar example is pi; it is always 3.14. So the gas constant is always equals 8.3144598 J/mol·K.
- Sun Jan 10, 2021 11:23 pm
- Forum: Ideal Gases
- Topic: Ideal gas law and reverse reactions
- Replies: 5
- Views: 211
Re: Ideal gas law and reverse reactions
I believe it would! Logically it makes a lot of sense
- Sun Jan 10, 2021 11:21 pm
- Forum: Ideal Gases
- Topic: PV=nRT
- Replies: 74
- Views: 5078
Re: PV=nRT
P is for pressure, V is for volume, n is number of moles of gas, R is the gas constant, T is for temperature
- Sun Jan 10, 2021 11:19 pm
- Forum: Ideal Gases
- Topic: partial pressures
- Replies: 14
- Views: 451
Re: partial pressures
Partial pressure is just the pressure the gas would have in the container if it was by itself. All the partial pressures add up to the total pressure of the container. But each gas is exerting its own pressure on the container. Hope that helps!
- Sun Jan 10, 2021 11:16 pm
- Forum: Ideal Gases
- Topic: Non-Ideal gases?
- Replies: 26
- Views: 1077
Re: Non-Ideal gases?
I don't believe we will cover it in this course. But you can always email him to make sure! But in the syllabus it didn't seem to mention it
- Sun Jan 10, 2021 11:10 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: H2O
- Replies: 44
- Views: 2217
Re: H2O
H20 is only included if it is in gaseous form. Other wise, in liquid or solid, it isn't needed to be included.
- Sun Jan 10, 2021 11:08 pm
- Forum: Ideal Gases
- Topic: Inert Gas
- Replies: 20
- Views: 720
Re: Inert Gas
An inert gas is the same as a noble gas. It's "inert" because it is unreactive and doesn't bond often.
- Wed Dec 16, 2020 11:07 am
- Forum: Naming
- Topic: Naming a compound
- Replies: 10
- Views: 3604
Re: Naming a compound
I usually start with the order the molecules will appear. Then the name of them. And then the oxidation number
- Wed Dec 16, 2020 10:58 am
- Forum: Lewis Acids & Bases
- Topic: Are these actually acidic?
- Replies: 5
- Views: 371
Re: Are these actually acidic?
For the most part I would assume pH testing would follow lewis acid and bases.
- Wed Dec 16, 2020 10:57 am
- Forum: Naming
- Topic: Determining charge when naming formulas
- Replies: 3
- Views: 398
Re: Determining charge when naming formulas
So the charge doesn't really have a name when naming compounds. However, it determines how many of each molecule there is. Like Na+ and Cl-, it going to have a 1 to 1 ratio to create NaCl. However Mg2+ and Cl-, would have MgCl2 (two chlorides). So that is how the charges can sometime come into play....
- Wed Dec 16, 2020 10:52 am
- Forum: Properties of Light
- Topic: Is c always the speed of light?
- Replies: 92
- Views: 6228
Re: Is c always the speed of light?
For this course, c will always be a constant and represent the speed of light
- Wed Dec 16, 2020 10:50 am
- Forum: Hybridization
- Topic: Double Pi Bonds
- Replies: 6
- Views: 972
Re: Double Pi Bonds
In a triple bond, there is one sigma bond and two pi bonds. I believe sigma bonds are end to end while pi bonds are side to side bonds.
- Wed Dec 16, 2020 10:49 am
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs Angular
- Replies: 20
- Views: 985
Re: Bent vs Angular
I believe they are the same thing
- Sun Dec 06, 2020 6:39 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: polar v nonpolar molecules
- Replies: 30
- Views: 2624
Re: polar v nonpolar molecules
non-polar molecules are symmetrical and have no dipole movement. Polar molecule are non-symmetrical and have dipole movement.
- Sun Dec 06, 2020 6:36 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Spin state
- Replies: 25
- Views: 1380
Re: Spin state
wait could you further explain what you mean? All that means, in each orbital there is only 2 electrons that are both spinning different ways. To denote that they are spinning in opposite direction we give it +1/2 or -1/2. It doesn't matter if the negative or positive comes first because all this n...
- Sun Dec 06, 2020 6:33 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Spin state
- Replies: 25
- Views: 1380
Re: Spin state
The spin state just simply means the directions the electrons are spinning in their orbital. So in each orbital there can only be 2 electrons. And in that orbital, they are both spinning different ways. And to denote that, we have the 4th quantum number denoting that its either +1/2 or -1/2.
- Sun Dec 06, 2020 6:29 pm
- Forum: Electronegativity
- Topic: Periodic Table Trend
- Replies: 40
- Views: 2644
Re: Periodic Table Trend
For ionization energy trend, it increases left to right because more energy is needed to remove the electrons from their valence shells. Like in group 1 and 2, they have low ionization energy because they give their electrons, often becoming cation. And in group 7, they have high ionization energy b...
- Sun Dec 06, 2020 6:21 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Lewis acids and bases
- Replies: 22
- Views: 1231
Re: Lewis acids and bases
I usually look at the formula. Acids are electron acceptors. So if you are to look at charges, H+ is what it will break into water. If it starts with H, it's most likely an acid because it will be the electron pair receptor. Bases are electron donors and in water will usually break into OH-. Bases m...
- Sun Dec 06, 2020 6:02 pm
- Forum: Lewis Acids & Bases
- Topic: Acids vs Basis
- Replies: 11
- Views: 678
Re: Acids vs Basis
My rule of thumb is usually look at the formula. If it starts with H, it's most likely an acid because it will be the electron pair receptor. Bases might have an OH in them as an electron pair donor. If that doesn't get you an answer, look at the structures and see which would be donating an electro...
- Sun Nov 29, 2020 11:44 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Cyclic Structure
- Replies: 3
- Views: 263
Re: Cyclic Structure
That just means the lewis structure forms a circle or ring in the structure. It's not linear like most of our lewis structures that we do. And in that sapling question I believe that the cyclic structure is that the carbon atoms form a triangle and the hydrogens branch off from that. I hope that was...
- Sun Nov 29, 2020 11:39 pm
- Forum: Significant Figures
- Topic: 40. versus 40
- Replies: 23
- Views: 1758
Re: 40. versus 40
Yes! 40. has 2 numbers in front of the decimal while 40 is only one sigfig because the zeros after don't count. That summary will be pretty helpful^^
- Sun Nov 29, 2020 11:36 pm
- Forum: Lewis Acids & Bases
- Topic: angle size
- Replies: 11
- Views: 469
Re: angle size
To be honest, it's very difficult to memorize the whole chart with bond angles. While you can think it out, it's very difficult and conceptual. My advice would be to find a chart you like and use it.This is one of the charts I use often and it helps me.
- Sun Nov 29, 2020 11:28 pm
- Forum: Resonance Structures
- Topic: Sapling #17
- Replies: 4
- Views: 300
Re: Sapling #17
Resonance structures are structures that are structurally similar, usually just multiple options. An example is CO3 2-, all similarly structured but with different spots for the double bond. In question 17, they all have the same molecular formula but have different structures so they aren't resonan...
- Sun Nov 29, 2020 11:13 pm
- Forum: Trends in The Periodic Table
- Topic: Ion Trends
- Replies: 28
- Views: 1503
Re: Ion Trends
I agree with everyone! I would probably say electronegativity would be the most important but Atomic radius, electron affinity, and ionization energy are important as well. But instead of trying to just memorize trends, try to think of why that trend occurs. For atomic radius it increases as you go ...
- Sun Nov 29, 2020 10:57 pm
- Forum: Balancing Chemical Reactions
- Topic: States of matter in chem equations
- Replies: 13
- Views: 1063
Re: States of matter in chem equations
In chem 14a it hasn't mattered too much if you're keeping track of states. But it is a good habit to get into. For most of the material we are doing now it won't affect your answers. But it will eventually matter later. Usually most states are given to you in the equation, and if not, it's possible ...
- Sun Nov 22, 2020 11:54 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionic radius
- Replies: 18
- Views: 936
Re: Ionic radius
Yes it does have an effect! When adding more electrons, it makes the ion more negative. This leads to more electron electron repulsion. This means an increase the size of the ion radius.
- Sun Nov 22, 2020 11:52 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionization Energy
- Replies: 19
- Views: 868
Re: Ionization Energy
It is talking about removing the electron from the outmost orbital because that requires the lowest energy. Everyone orbital after that requires much more energy.
- Sun Nov 22, 2020 11:48 pm
- Forum: Quantum Numbers and The H-Atom
- Topic: Clarification on the 4th quantum number
- Replies: 5
- Views: 391
Re: Clarification on the 4th quantum number
You will needs to know what ms is, which is the spin. For what we have to know in 14a it basically indicates one specific electron in the orbital vs when they don't mention ms it usually is has 2. Hopefully that makes sense! But you wont have to try to differentiate between +1/2 and -1/2
- Sun Nov 22, 2020 11:42 pm
- Forum: Electronegativity
- Topic: Tips on remembering trend
- Replies: 5
- Views: 338
Re: Tips on remembering trend
I don't know if this will help but I remember it by how the elements want to complete the octet. For example elements in group one and two aren't trying to fill their valence shell so low they have low electronegativity. While group 7 really wants to fill their valence shell and only needs one more ...
- Sun Nov 22, 2020 11:01 pm
- Forum: Lewis Acids & Bases
- Topic: Determining Lewis Acids and Bases
- Replies: 9
- Views: 619
Re: Determining Lewis Acids and Bases
I usually look at charge or position on the periodic table of the element or ion. The most basic definitions are a lewis acid is an electron pair acceptor and a lewis base is an electron pair donor. As said above, lone pairs usually indicate donors. Acids usually needs electrons is another hint as w...
- Sun Nov 15, 2020 9:22 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Best Formal Charge Equations
- Replies: 24
- Views: 1165
Best Formal Charge Equations
What are some good formal charge equations? Or easier ways to remember them? Cuz I have seen multiple ways people find the formal charge and a tad confused.
- Sun Nov 15, 2020 9:19 pm
- Forum: Electronegativity
- Topic: Electronegativity
- Replies: 9
- Views: 477
Re: Electronegativity
The reason electronegativity decreases down the periodic table is because the atomic radius increases. An increases in the radius means there are more shells and the electrons are farther away so there is less of an attraction.
- Sun Nov 15, 2020 8:51 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Sapling #9 week 5/6
- Replies: 13
- Views: 771
Sapling #9 week 5/6
How do you determine which resonance structure is best based on formal charge? Alittle confused on the process
- Sun Nov 15, 2020 8:08 pm
- Forum: Ionic & Covalent Bonds
- Topic: Sapling #13
- Replies: 8
- Views: 369
Re: Sapling #13
Ya it took me awhile to figure it out as well. But look at the electronegative atoms with lone pairs and the hydrogen atoms. The 4 hydrogens are able to form 4 hydrogen bonds with electronegative atoms. There are 2 nitrogen with a lone pair each so they can form a hydrogen bond each so that is 2 mor...
- Sun Nov 15, 2020 8:02 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Spin State
- Replies: 8
- Views: 863
Re: Spin State
I would assume because in an orbital there is 2 options of which way it "spins". So +1/2 and -1/2 is to differentiate between them
- Sun Nov 15, 2020 8:00 pm
- Forum: Ionic & Covalent Bonds
- Topic: Atomic Radius vs Covalent Radius
- Replies: 6
- Views: 3374
Re: Atomic Radius vs Covalent Radius
Yes there is a difference! Atomic radius is the most common term, which is the distance to the atoms nucleus. A covalent radius is when you measure the distance between two covenantally bonded atoms and take half the distance.
- Sun Nov 08, 2020 7:04 pm
- Forum: Lewis Structures
- Topic: Sapling #3
- Replies: 10
- Views: 625
Re: Sapling #3
For the most part its guess and check work which can get tedious, but just use the formula charge equation to help if you need. The more you do the better you will get at them so don't worry! You got it.
- Sun Nov 08, 2020 6:52 pm
- Forum: Lewis Structures
- Topic: lewis structure
- Replies: 17
- Views: 655
Re: lewis structure
The brackets help indicate that the molecule is an ion, and the charge outside the brackets is the total charge of the ions.
- Sun Nov 08, 2020 6:48 pm
- Forum: Lewis Structures
- Topic: Sapling Weeks 5-6 HW Question 2
- Replies: 7
- Views: 396
Re: Sapling Weeks 5-6 HW Question 2
arisawaters3D wrote:How do you know when it's best to use a double bond as opposed to using a single bond and a lone pair?
If you want to lower the number of bonds. Because in a double bond creates a double bond, while a single bond will leave two lone pairs, one lone pair on each of the atoms in the bond.
- Sun Nov 08, 2020 6:44 pm
- Forum: Lewis Structures
- Topic: Lewis Acid vs. Lewis Base
- Replies: 5
- Views: 425
Re: Lewis Acid vs. Lewis Base
CO2 has double bonds in it, so it can attract and accept electrons. This qualifies it as a Lewis Acid. I hope that helps!
If you look at the reaction between H20 and C02 can possibly help too.
If you look at the reaction between H20 and C02 can possibly help too.
- Sun Nov 08, 2020 6:23 pm
- Forum: Resonance Structures
- Topic: Sapling Week 5/6 #9
- Replies: 3
- Views: 148
Sapling Week 5/6 #9
How can we determine which resonance structure is most plausible based on formal charge and oxidation number? This is referencing problem 9 from sapling. I know how to get those numbers but based on that information how do we determine which resonance structure?
- Sun Nov 08, 2020 6:08 pm
- Forum: Ionic & Covalent Bonds
- Topic: London dispersion forces
- Replies: 12
- Views: 834
London dispersion forces
Can someone explain what London dispersion forces are? And how to differentiate between how strong the forces are?
- Sun Nov 01, 2020 11:38 pm
- Forum: Properties of Electrons
- Topic: Energy of Electrons
- Replies: 2
- Views: 222
Re: Energy of Electrons
Thank You!
- Sun Nov 01, 2020 11:34 pm
- Forum: Properties of Light
- Topic: Number of photons
- Replies: 1
- Views: 148
Number of photons
I am a tad confused on what the question means when they ask for number of photons? sapling #4 is a similar to what I'm asking. Also how would you find the number of protons as well?
- Sun Nov 01, 2020 11:25 pm
- Forum: Properties of Electrons
- Topic: Energy of Electrons
- Replies: 2
- Views: 222
Energy of Electrons
How would I find the energy of an electron based on the wavelength? This is based on question 13 of sapling
- Sun Nov 01, 2020 11:08 pm
- Forum: Lewis Structures
- Topic: Dot order
- Replies: 11
- Views: 879
Re: Dot order
I don't believe there is any official rules to do it. Just that 2 dots are paired and a single is an unpaired electron, so make sure to keep track of that!
- Sun Nov 01, 2020 11:04 pm
- Forum: Ionic & Covalent Bonds
- Topic: Nonpolar and polar
- Replies: 16
- Views: 1148
Re: Nonpolar and polar
DMaya_3C wrote:Does electronegativity have any connection with a molecule being polar or nonpolar?
Yes it does! That's what cause polar bonds, the electronegativity difference cause there to be uneven sharing of electrons.
- Sun Nov 01, 2020 10:58 pm
- Forum: Lewis Structures
- Topic: Octet Rule
- Replies: 12
- Views: 502
Re: Octet Rule
The elements that do not follow the octet rule are H, He, Li, and Be. They are in 1s and 2s orbitals so they can not get a full valence shell. I believe there are others but these are the only one discussed so far.
- Sun Oct 25, 2020 11:51 pm
- Forum: *Black Body Radiation
- Topic: Info for Midterm
- Replies: 13
- Views: 1173
Re: Info for Midterm
I don't believe he will be testing us on it. You can always email your ta to ask! but because it was so brief I wouldn’t be too worried.
- Sun Oct 25, 2020 11:50 pm
- Forum: Properties of Electrons
- Topic: Sapling 2 #6
- Replies: 4
- Views: 117
Re: Sapling 2 #6
Both ways should be fine! My ta did it one way but a couple of the other kids in my discussion did it the way you did and she said it was okay. If it is getting you the right answer you should be good. It's just a different form of units.
- Sun Oct 25, 2020 11:46 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Equations Coefficient Question
- Replies: 24
- Views: 2768
Re: Balancing Equations Coefficient Question
Yes, that is exactly right! Using fractions and non-whole numbers makes it more difficult to solve. And when you multiply by 2 on each side, it does not unbalance the equation because you are doing it to both sides.
- Sun Oct 25, 2020 11:44 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: When would 3d orbital be filled before the 4s orbital?
- Replies: 8
- Views: 534
Re: When would 3d orbital be filled before the 4s orbital?
You always fill 4s orbital first, except with Cr and Cu. 4s has a lower energy so it fills before 3d. Just follow the order above^^ and it will work for most of the time.
- Sun Oct 25, 2020 11:35 pm
- Forum: Trends in The Periodic Table
- Topic: Atomic Radius
- Replies: 30
- Views: 3195
Re: Atomic Radius
Atomic radius decreases from left to right and increases as you go down. It increases as you go down because the number of energy levels increases, so there is a greater distance between the nucleus and the outermost orbital. From left to right it decreases because of the charges of the nucleus pull...
- Sun Oct 25, 2020 9:34 pm
- Forum: Trends in The Periodic Table
- Topic: Electronegativity
- Replies: 11
- Views: 728
Re: Electronegativity
Just knowing the general trends of electronegativity will be usual for the midterm and can aid you when trying to determine other problems. For the most part, electronegativity increases from left to right and decreases as you go down the period table.