Search found 113 matches
- Sat Mar 14, 2020 9:30 pm
- Forum: General Rate Laws
- Topic: Rate Constant
- Replies: 31
- Views: 1131
Rate Constant
Wasn't sure where to put this, but is there anything that can alter a reaction's rate constant (for example, temperature or pressure)? Or does the rate constant remain the same in all situations?
- Sat Mar 14, 2020 8:49 pm
- Forum: General Rate Laws
- Topic: How to use general rate laws to find rates of specific equations?
- Replies: 4
- Views: 520
Re: How to use general rate laws to find rates of specific equations?
Wait never mind, I found the unimolecular/bimolecular info in my notes! Thanks!
- Sat Mar 14, 2020 8:35 pm
- Forum: General Rate Laws
- Topic: How to use general rate laws to find rates of specific equations?
- Replies: 4
- Views: 520
Re: How to use general rate laws to find rates of specific equations?
Rate laws can be used in this question because for bimolecular reactions like the one in part a, the rate is simply equal to k[NO}^2, because there are two molecules of NO reacting and colliding with each other. This makes the coefficient for NO 2, and thus that becomes the exponent in the rate law...
- Sat Mar 14, 2020 8:31 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Take Home Final
- Replies: 16
- Views: 974
Re: Take Home Final
Do you guys think it will be all MC questions with a purely correct/incorrect grading style? I'd imagine there would be some multiple choice and some fill-in-the-blank, but I think since we probably can't show work it would be a full correct/incorrect grading scale. Also, since Prof Lavelle also me...
- Sat Mar 14, 2020 8:24 pm
- Forum: General Rate Laws
- Topic: How to use general rate laws to find rates of specific equations?
- Replies: 4
- Views: 520
How to use general rate laws to find rates of specific equations?
How do you use rate laws to find the rate of a specific reaction? For example, in 7C 1:
Each of the following is an elementary reaction. Write its rate law and state its molecularity. (a) NO + NO --> N2O2; (b) Cl2 --> Cl + Cl.
Each of the following is an elementary reaction. Write its rate law and state its molecularity. (a) NO + NO --> N2O2; (b) Cl2 --> Cl + Cl.
- Sat Mar 14, 2020 6:21 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Partial Credit
- Replies: 2
- Views: 243
Re: Partial Credit
Ooh, I'm not sure about that, but I know usually when we do problems it's best to just keep all of the decimal points in intermediate answers before we get to the final answer. So only round to sigfigs at the final product.
- Sat Mar 14, 2020 6:17 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Final- general questions
- Replies: 12
- Views: 858
Re: Final- general questions
It's open book/open note, is 30 qs/5 pts each, starts at 11:15 on CCLE, and lasts 3.5 hours. Prof Lavelle said most people should finish it in 2 so that should be a good sign.
- Sat Mar 14, 2020 6:15 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: 7B 3(c)
- Replies: 2
- Views: 279
7B 3(c)
Determine the rate constant for each of the following first order reactions, in each case expressed for the rate of loss of A: (c) 2A --> B + C, given that [A]0 = 0.153 mol/L and that after 115 s the concentration of B rises to 0.034 mol/L. I was able to do parts (a) and (b) for this problem, but I'...
- Tue Mar 10, 2020 12:06 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Developing a Proposed Reaction Mechanism
- Replies: 3
- Views: 230
Developing a Proposed Reaction Mechanism
When creating a possible reaction mechanism, do we generally just have to find one by trial and error? Are there any specific guidelines to keep in mind for developing a reaction mechanism?
- Tue Mar 10, 2020 12:03 am
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Adsorption
- Replies: 7
- Views: 385
Re: Adsorption
805312064 wrote:Okay that makes sense. One more question, what does adhesion/adsorption have to do with catalysts?
Basically, when an enzyme is catalyzing a reaction, the substrates are not absorbed INTO the enzyme. Rather, they sit on top of it in a specific active site.
- Tue Mar 10, 2020 12:01 am
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Reactant for Initial Rate
- Replies: 2
- Views: 170
Reactant for Initial Rate
Why do we only use reactant rate for initial rate (and not product)? Also, in which reactions is this rule used (like is this used only when calculating a specific order reaction or is this used for all reactions)?
- Tue Mar 10, 2020 12:00 am
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Determining reaction rate for overall reaction
- Replies: 3
- Views: 273
Determining reaction rate for overall reaction
How do we know what the rate limiting reaction within a proposed reaction mechanism is? I know that it has the slowest rate, but is this something we generally calculate ourselves (if so, how?) or not?
- Mon Mar 09, 2020 11:58 pm
- Forum: Second Order Reactions
- Topic: Derivations of Reactions
- Replies: 5
- Views: 446
Derivations of Reactions
Will we need to know how to derive 0-, 1- or 2-order reaction equations for the final?
- Mon Mar 02, 2020 10:31 am
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Ways to calculate Gibbs free energy
- Replies: 5
- Views: 342
Re: Ways to calculate Gibbs free energy
I think it mostly just depends on what they give you. If you're given a table with delta G of different molecules, then you use the second one. I understand this, but for one of the homework questions (5J 15), we were supposed to use different methods of finding deltaG at different temperatures (25...
- Mon Mar 02, 2020 10:26 am
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L 9
- Replies: 2
- Views: 195
6L 9
(a) Write balanced half-reactions for the redox reaction of an acidified solution of potassium permanganate and iron(II) chloride. (b) Write the balanced equation for the cell reaction and devise a galvanic cell to study the reaction (write its cell diagram Why do we not include the Cl and the K in ...
- Sun Mar 01, 2020 10:32 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: n value
- Replies: 4
- Views: 367
Re: n value
The n value should always be the same for a specific redox reaction, as half reactions are multiplied by a scalar in order to equalize number of electrons on both sides before they are added to create a fully balanced reaction. This equivalent number of electrons is what should be used in Nernst.
- Sun Mar 01, 2020 10:29 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Ways to calculate Gibbs free energy
- Replies: 5
- Views: 342
Ways to calculate Gibbs free energy
For cell/redox problems, when do we use deltaG = deltaH - TdeltaS and deltaG = deltaG(products) - deltaG(reactants)?
- Sun Mar 01, 2020 10:27 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Galvanic Cells and pH
- Replies: 1
- Views: 231
Galvanic Cells and pH
Do the sides of galvanic cells (anode and cathode) have different pH, and if so, how might that affect how we solve for half reactions?
- Sun Mar 01, 2020 10:26 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: 6L 7
- Replies: 1
- Views: 106
6L 7
Write the half-reactions and devise a galvanic cell (write a cell diagram) to study each of the following reactions: (a) AgBr(s) <---> Ag+(aq) + Br-(aq), a solubility equilibrium (b) H+(aq) + OH-(aq) ---> H2O(l), the Brønsted neutralization reaction (c) Cd(s) + 2Ni(OH)3(s) ---> Cd(OH)2(s) + 2Ni(OH)2...
- Sun Mar 01, 2020 10:20 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Test 2
- Replies: 4
- Views: 286
Test 2
Do you guys think for this upcoming test we are going to have to look up Eo values on a table like we had to for the midterm?
- Fri Feb 28, 2020 6:21 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 5J 15
- Replies: 3
- Views: 266
Re: 5J 15
D is actually deuterium and the values can be found in the Appendix You could use that formula at 25 degrees celsius since the values in the appendix are at that temperature. However, for 150 degrees celsius, you'll need to use the equation delta G= delta H-T(delta S) Hope that helps! Oh ok, thanks...
- Thu Feb 27, 2020 2:33 am
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: 5J 15
- Replies: 3
- Views: 266
5J 15
Calculate the equilibrium constant at 25 8C and at 150 8C for each of the following reactions, using data available in Appendix 2A: (a) NH4Cl(s) <--> NH3(g) + HCl(g) (b) H2(g) + D2O(l) <--> D2(g) + H2O(l) How do we calculate for (b)? What values do we use for this, as D2O and D2 obviously are not te...
- Sun Feb 23, 2020 11:11 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: galvanic cell function
- Replies: 2
- Views: 127
galvanic cell function
I wasn't in class for lecture this week so I don't fully understand the cell diagram for a galvanic cell. Exactly how does a galvanic cell work (through redox reaction, salt bridge/porous disk, etc)?
- Sun Feb 23, 2020 11:07 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: STP
- Replies: 13
- Views: 705
Re: STP
We need to assume 273 K/0 C temperature and 1 atm pressure under STP.
- Sun Feb 23, 2020 11:06 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Eo as an intensive property
- Replies: 9
- Views: 608
Eo as an intensive property
Why exactly is Eo intensive?
- Sun Feb 23, 2020 11:01 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Assuming conditions
- Replies: 2
- Views: 156
Assuming conditions
In what situations would we assume 1 M solution or 1 atm at 25 degrees Celsius?
- Sun Feb 23, 2020 10:59 pm
- Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
- Topic: Calculation of Eo of a cell
- Replies: 3
- Views: 247
Re: Calculation of Eo of a cell
AngieGarcia_4F wrote:I think what equation you'd use would depend on what info the question provides
Specifically what info would you need to know from the question to distinguish between the two? What if you don't necessarily have all of the info you might need?
- Sun Feb 16, 2020 5:03 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Gibbs Free Energy of a System
- Replies: 2
- Views: 89
Gibbs Free Energy of a System
Can someone explain conceptually what the overall Gibbs Free Energy of a system equation means?
deltaG = deltaG* + RTlnQ
How does this relate to deltaG = deltaH - TdeltaS? Are these equal to each other or is the second equation supposed to be deltaG* in the first equation?
deltaG = deltaG* + RTlnQ
How does this relate to deltaG = deltaH - TdeltaS? Are these equal to each other or is the second equation supposed to be deltaG* in the first equation?
- Sun Feb 16, 2020 4:59 pm
- Forum: Van't Hoff Equation
- Topic: K in Van't Hoff
- Replies: 3
- Views: 228
K in Van't Hoff
How/why does K as the equilibrium constant relate into the Van't Hoff equation? What does that mean conceptually?
- Sun Feb 16, 2020 4:57 pm
- Forum: Balancing Redox Reactions
- Topic: How do you combine half reactions?
- Replies: 4
- Views: 306
Re: How do you combine half reactions?
So would this be similar to how in Hess's law we would add intermediate equations to make the final reaction?
- Sun Feb 16, 2020 4:55 pm
- Forum: Balancing Redox Reactions
- Topic: Electrons in Compounds
- Replies: 1
- Views: 80
Electrons in Compounds
Just to clarify, when you are trying to figure out how many electrons are in a compound (for redox reactions), no matter if the compound is covalent or ionic you usually just use the butterfly method (for H2O, the 1 subscript from O goes to the top of H - making it +1 - while the 2 subscript from H ...
- Sun Feb 16, 2020 4:49 pm
- Forum: Balancing Redox Reactions
- Topic: oxidation vs reduction
- Replies: 19
- Views: 925
Re: oxidation vs reduction
In oxidation, an atom loses electrons while in reduction electrons are gained (OILRIG). Specifically in situations where the electrons are in compounds, the best way to be able to tell if some atom has been oxidized or reduced is by figuring out how many electrons each atom in a compound has through...
- Mon Feb 10, 2020 7:58 pm
- Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
- Topic: Relationship between Delta S Surroundings and Delta S System
- Replies: 1
- Views: 187
Relationship between Delta S Surroundings and Delta S System
Other than del(S surr) + del(S sys) = del(S univ), how are del(S surr) and del(S sys) related? Like how can you find del(S surr) if you only have del(S sys) or vice versa? What other information would you need for that? Also, under what conditions might del(S surr) = -del(S sys) be true - in other w...
- Sun Feb 09, 2020 11:00 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Reversible and Irreversible Reactions
- Replies: 3
- Views: 410
Reversible and Irreversible Reactions
I wasn't super sure where to put this, but I wanted to know how to tell the difference between reversible and irreversible reactions. Are phase changes reversible? What are the markers to know whether a chemical reaction is reversible or irreversible?
- Sun Feb 09, 2020 10:26 pm
- Forum: Student Social/Study Group
- Topic: Number of Chemistry Community Posts
- Replies: 45
- Views: 2393
Re: Number of Chemistry Community Posts
Sometimes I post multiple times on the same thread - is this counted as separate posts or as just one?
- Sun Feb 09, 2020 10:24 pm
- Forum: Student Social/Study Group
- Topic: Midterm Topics
- Replies: 12
- Views: 678
Re: Midterm Topics
Do we know how much of each topic will be on the midterm? Will it be similar to Pizza Rolls where there was a clearly heavier focus on more recent stuff or will it be more equal between equilibrium and enthalpy/entropy/Gibbs free energy?
- Sun Feb 09, 2020 10:22 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Entropy calculations (rev and irrev)
- Replies: 2
- Views: 184
Entropy calculations (rev and irrev)
Delta S = q(rev)/T can only be used for reversible reactions, right? Does this mean other ways to find delta S, such as nC(T2/T1) or nR(P1/P2) etc only apply to irreversible reactions, or can this be used for both?
- Sun Feb 09, 2020 10:18 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: m and n in heat capacity
- Replies: 4
- Views: 172
m and n in heat capacity
Why can we use mass and moles in different heat capacity equations and still get an equivalent result?
- Sun Feb 09, 2020 10:16 pm
- Forum: Third Law of Thermodynamics (For a Unique Ground State (W=1): S -> 0 as T -> 0) and Calculations Using Boltzmann Equation for Entropy
- Topic: Types of Entropy Calculations
- Replies: 2
- Views: 204
Types of Entropy Calculations
I've noticed that change of entropy calculations using moles/temperature/volume etc tend to be much larger than entropy calculations using degeneracy and Boltzmann's constant - are these two types of calculations calculating entropy at different levels, and if so, what are they?
- Sun Feb 09, 2020 10:13 pm
- Forum: Student Social/Study Group
- Topic: Midterm Studying
- Replies: 5
- Views: 344
Midterm Studying
Hey everyone! I was wondering how to best approach studying for the upcoming midterm? I feel like there is so much to remember and understand how to use and I'm not very confident in the studying I'm doing (redoing all the homework questions) because it just feels like a lot of busy work and I don't...
- Sun Feb 09, 2020 10:05 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Cv vs Cp
- Replies: 3
- Views: 112
Re: Cv vs Cp
I have another question related to this - in Lyndon's review session for Pizza Rolls today he used Cv for a problem that had changing volume (problem 5) and I don't understand why. He said you usually use Cv (he might have offered an explanation but I didn't really hear/understand).
- Sun Feb 02, 2020 11:51 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Cv vs Cp
- Replies: 3
- Views: 112
Cv vs Cp
How can we use Cv and Cp when looking into heat required to change the temperature of a system (qp = n(Cp/v)(DeltaT))? I know one of them is for constant volume and the other is for constant pressure, but are there calculation-based differences between the two, or are both found the exact same way?
- Sun Feb 02, 2020 11:38 pm
- Forum: Concepts & Calculations Using First Law of Thermodynamics
- Topic: Different ways to calculate change in U
- Replies: 4
- Views: 155
Different ways to calculate change in U
How do you calculate the change in U for different situations: constant/changing pressure, temperature, volume etc?
- Sun Feb 02, 2020 8:28 pm
- Forum: Calculating Work of Expansion
- Topic: 4A.5
- Replies: 2
- Views: 142
4A.5
A piston confines 0.200 mol Ne(g) in 1.20 L at 25 8C. Two experiments are performed. (a) The gas is allowed to expand through an additional 1.20 L against a constant pressure of 1.00 atm. (b) The gas is allowed to expand reversibly and isothermally to the same final volume. Which process does more w...
- Sun Feb 02, 2020 8:19 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Advice from a Medical Student - Part II [ENDORSED]
- Replies: 298
- Views: 244842
Re: Advice from a Medical Student - Part II [ENDORSED]
Thanks so much for sharing your story with us and being open to questions! It sounds like being able to learn about disease and do some work in the hospital is a blast. I have heard a lot about medical school - namely, that it requires a lot of rote memorization - but I believe I learn better by und...
- Sun Feb 02, 2020 8:15 pm
- Forum: Calculating Work of Expansion
- Topic: Change in Pressure vs Constant Pressure
- Replies: 1
- Views: 43
Change in Pressure vs Constant Pressure
In some homework questions, a pressure unit is mentioned to calculate work over some time, but there is no other pressure unit to compare it with. Are we right to assume that it should be constant pressure?
- Sun Jan 26, 2020 4:46 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Types of Delta H
- Replies: 3
- Views: 97
Types of Delta H
I know that delta H alone is a reaction's enthalpy and that delta Hf is standard enthalpy of formation, but in one of the homework problems (4D15) I came across delta Hc; does anybody know what this means?
- Wed Jan 22, 2020 7:22 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Strong Acids and Bases in Water
- Replies: 1
- Views: 75
Strong Acids and Bases in Water
How should we go about trying to find the pH or pOH of a solution where a strong acid or base is poured into water? Like I know the pH or pOH shouldn't change much and we don't use an ice table, but then what can we do to find the pH?
- Mon Jan 20, 2020 4:29 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Percentage Protonation
- Replies: 1
- Views: 96
Percentage Protonation
What is the equation to find percentage protonation? What does percentage protonation measure?
- Mon Jan 20, 2020 3:27 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: 6B 9
- Replies: 3
- Views: 190
6B 9
(a) Complete the following table. (b) Rank the four solutions in order of increasing acidity. [H3O+] [OH-] pH pOH (i) [H3O+] is 1.50 mol/L (ii) [OH-] 1.50 mol/L (iii) pH is 0.75 (iv) pOH is 0.75 When calculating pH for the first two rows, the pH and pOH were either negative or over 14. Is this possi...
- Mon Jan 20, 2020 3:24 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: 6B 11
- Replies: 3
- Views: 199
6B 11
A student added solid Na2O to a volumetric flask of volume 200.0 mL, which was then filled with water, resulting in 200.0 mL of NaOH solution. Then 5.00 mL of the solution was transferred to another volumetric flask and diluted to 500.0 mL. The pH of the diluted solution is 13.25. (a) What is the mo...
- Sun Jan 19, 2020 4:20 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: Acids/Bases and Chemical Equilibrium
- Replies: 2
- Views: 114
Acids/Bases and Chemical Equilibrium
I understand the steps to do chemical equilibrium problems for chemical equations that aren't acids and bases; in general, what is added to the basic framework of solving regular chemical equilibrium reactions when trying to find chemical equilibria (and related pH/pOH) for acid base reactions?
- Sun Jan 19, 2020 4:13 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 5I 33
- Replies: 2
- Views: 93
5I 33
A sample of ammonium carbamate, NH4(NH2CO2), of mass 25.0 g was placed in an evacuated flask of volume 0.250 L and kept at 25 C. At equilibrium, 17.4 mg of CO2 was present. What is the value of Kc for the decomposition of ammonium carbamate into ammonia and carbon dioxide? The reaction is NH4(NH2CO2...
- Sun Jan 19, 2020 4:08 pm
- Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
- Topic: Le Chatelier's Principle
- Replies: 4
- Views: 56
Le Chatelier's Principle
How can Le Chatelier's principle be applied to partial pressures?
- Thu Jan 16, 2020 1:44 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Approximation
- Replies: 8
- Views: 269
Approximation
Can someone explain how and when we use approximation for ICE tables? Are there other situations you can use them as well? Is this only for acids and bases?
- Wed Jan 15, 2020 5:02 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: 6A 21
- Replies: 2
- Views: 80
6A 21
The value of Kw for water at body temperature (37 C) is
2.1 * 10^-14. (a) What is the molar concentration of H3O+ ions at
37 C? (b) What is the molar concentration of OH- in neutral
water at 37 C?
I understand that Kw = [H3O+][OH-], but I am not sure where to go from here.
2.1 * 10^-14. (a) What is the molar concentration of H3O+ ions at
37 C? (b) What is the molar concentration of OH- in neutral
water at 37 C?
I understand that Kw = [H3O+][OH-], but I am not sure where to go from here.
- Sun Jan 12, 2020 12:41 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Factors Affecting K
- Replies: 5
- Views: 189
Factors Affecting K
What factors change a K value of an equilibrium reaction (other than temperature), and why?
- Sun Jan 12, 2020 12:39 pm
- Forum: Non-Equilibrium Conditions & The Reaction Quotient
- Topic: ICE vs Normal Concentrations
- Replies: 5
- Views: 142
ICE vs Normal Concentrations
In what situations should we use the ICE method; in what situations should we use regular equilibrium concentrations?
- Sun Jan 12, 2020 12:37 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Temperature and K
- Replies: 6
- Views: 241
Temperature and K
What effect does temperature have on the K value, and why does the K value change with temperature?
- Sun Jan 12, 2020 12:36 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Pure substances in reactions
- Replies: 2
- Views: 51
Pure substances in reactions
Can there never be any reactions that only contain pure substances (purely liquid or solid)? For example, are reactions like the ones modeled below never possible? If so, why?
Solid + Solid <--> Solid
Liquid + Liquid <--> Liquid
Liquid + Solid <--> Solid + Liquid
Solid + Solid <--> Solid
Liquid + Liquid <--> Liquid
Liquid + Solid <--> Solid + Liquid
- Sun Jan 12, 2020 12:33 pm
- Forum: Ideal Gases
- Topic: Bars vs atmospheres
- Replies: 13
- Views: 302
Bars vs atmospheres
What is the difference between bars and atmospheres as units for finding Kp or Qp? Which one is used, and if it is either, why are both applicable?
- Sun Dec 08, 2019 12:43 am
- Forum: Air Pollution & Acid Rain
- Topic: Options to reduce acid rain
- Replies: 8
- Views: 548
Re: Options to reduce acid rain
Riya Sood 4C wrote:Acid rain can be reduced by reducing burning of fossil fuels. Also, neutralizers like limestone can be used
is that all we have to know for the final about neutralizing acid rain? Are there any specific chemical concepts we should know behind these options to reduce acid rain?
- Sun Dec 08, 2019 12:37 am
- Forum: Acidity & Basicity Constants and The Conjugate Seesaw
- Topic: Using Ka or Kb to find pKa or pKb
- Replies: 2
- Views: 119
Using Ka or Kb to find pKa or pKb
We have the formulas to find pKa and pKb, but if we are given an acid or base without the Ka or Kb how do we find the pKa or pKb? Or do we need to be given the Ka or Kb to find this?
- Sun Dec 08, 2019 12:35 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Chelating Ligand
- Replies: 1
- Views: 227
Chelating Ligand
When we say a chelating ligand forms a ring around the central metal atom, do we mean that the metal atom is a part of the ring created? How do we know is something is a chelating ligand without knowing the drawing of it? Also, how do we know how to draw a chelating ligand knowing only the chemical ...
- Sun Dec 08, 2019 12:31 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Coordination Compounds Structures
- Replies: 1
- Views: 147
Coordination Compounds Structures
How can we draw coordination compounds and know the VSEPR geometry of the compound? How can we tell the number of valence electrons on the transition metal in the center of the compound?
- Sun Dec 08, 2019 12:26 am
- Forum: Air Pollution & Acid Rain
- Topic: Options to reduce acid rain
- Replies: 8
- Views: 548
Options to reduce acid rain
What are some ways we can reduce acid rain?
- Sun Dec 08, 2019 12:23 am
- Forum: Biological Examples
- Topic: Important Complexes and their Biological Significance
- Replies: 2
- Views: 277
Important Complexes and their Biological Significance
Which complexes should we know in terms of biological significance (and which formulas should we memorize)?
- Sun Dec 08, 2019 12:22 am
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Memorizing Ligands
- Replies: 3
- Views: 226
Memorizing Ligands
Which ligands should we know the formulas for by heart other than edta, en and ox?
- Sat Dec 07, 2019 11:17 pm
- Forum: Sigma & Pi Bonds
- Topic: Hybridization Notation for Sigma and Pi Bonds
- Replies: 1
- Views: 222
Hybridization Notation for Sigma and Pi Bonds
How do we denote hybridization for sigma and pi bonds (something like sigma(C2sp, C2sp) or smth)?
- Sat Dec 07, 2019 4:12 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma Vs Pi
- Replies: 12
- Views: 754
Sigma Vs Pi
What are the main differences between sigma and pi bonds? What do we need to know and why are these differences important?
- Sun Dec 01, 2019 8:04 pm
- Forum: Conjugate Acids & Bases
- Topic: Ligands
- Replies: 12
- Views: 599
Ligands
Exactly what is a ligand, and what do we need to know about ligands from lectures for the final?
- Sun Dec 01, 2019 8:03 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted Acid and Base
- Replies: 5
- Views: 267
Re: Bronsted Acid and Base
Yes, bronsted definitions are based on proton accepting or donating (in contrast to lewis definitions based on electron accepting and donating).
- Sun Dec 01, 2019 8:00 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Studying for final exam
- Replies: 8
- Views: 609
Re: Studying for final exam
I've heard that the final can be very specific, so I think studying the notes or even the textbook in depth will really help.
- Sun Dec 01, 2019 7:59 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Sigma Bond
- Replies: 10
- Views: 575
Re: Sigma Bond
Sigma bonds are always one of the (up to three) bonds in a bond between two atoms. Specifically, there is one sigma in a single bond, one sigma in a double bond and one sigma in a triple bond.
- Sun Dec 01, 2019 7:57 pm
- Forum: Lewis Acids & Bases
- Topic: Proton acceptor and proton donor?
- Replies: 33
- Views: 2019
Re: Proton acceptor and proton donor?
Proton acceptors are bases and proton donors are acids
- Sun Nov 24, 2019 11:27 pm
- Forum: Resonance Structures
- Topic: Resonance and Naming
- Replies: 11
- Views: 837
Re: Resonance and Naming
Resonance should not affect how we name a compound. However, having different versions of the compound's composition (such as through cisplatin and transplatin) can affect naming of a compound.
- Sun Nov 24, 2019 11:25 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bond Angles
- Replies: 7
- Views: 472
Re: Bond Angles
This depends on if there is greater repulsion of bonds based on polarity and lone pairs. For example, H2O has slightly less than 109.5 degrees bond angle because the lone pairs on the oxygen repel the hydrogens away from the lone pairs and closer together to each other.
- Sun Nov 24, 2019 11:22 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: 2F.3
- Replies: 3
- Views: 124
Re: 2F.3
(a) 2 sigma bonds
(b) 2 sigma and 2 pi bonds
You can tell based on the lewis structure - single bonds are one sigma bond, double bonds are one sigma and one pi bond, and triple bonds are one sigma and two pi bonds.
(b) 2 sigma and 2 pi bonds
You can tell based on the lewis structure - single bonds are one sigma bond, double bonds are one sigma and one pi bond, and triple bonds are one sigma and two pi bonds.
- Sun Nov 24, 2019 8:01 pm
- Forum: Biological Examples
- Topic: Cisplatin
- Replies: 12
- Views: 600
Re: Cisplatin
You should know cisplatin has a different structure than the trans version of the molecule because of sigma and pi bonds and the lewis structures of each.
- Sun Nov 24, 2019 7:40 pm
- Forum: Lewis Acids & Bases
- Topic: Donor and Acceptor
- Replies: 6
- Views: 316
Re: Donor and Acceptor
Im pretty sure Lewis acids and bases are the same as regular acida dn bases. Lewis acids are proton donors and electron acceptors; lewis bases are proton acceptors and electron donors.
- Sun Nov 17, 2019 8:15 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Molecular Shapes
- Replies: 6
- Views: 402
Re: Molecular Shapes
I'd assume we need to memorize them all along with whatever electron configuration they go with for test 2.
- Sun Nov 17, 2019 8:13 pm
- Forum: *Liquid Structure (Viscosity, Surface Tension, Liquid Crystals, Ionic Liquids)
- Topic: Rod vs spherical shaped molecules
- Replies: 10
- Views: 1624
Re: Rod vs spherical shaped molecules
Rod-shaped molecules have stronger London dispersion bonds because they have more surface area as well as more extreme electron clumping/shifting.
- Sun Nov 17, 2019 8:11 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Boiling Points
- Replies: 7
- Views: 537
Re: Boiling Points
Essentially, does this mean that boiling points have a direct correlation to electronegativity? I would think that if an atom is more electronegative then there is a stronger bond and thus a higher boiling point. I would say it is more about the difference in electronegativities between atoms in a ...
- Sun Nov 17, 2019 8:07 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Polar vs non polar
- Replies: 5
- Views: 255
Re: Polar vs non polar
No - polarity depends more on whether the individual polarity between atoms in a single molecule cancel out or not. You cannot just assume that all molecules with lone pairs are polar as a whole.
- Sun Nov 17, 2019 8:06 pm
- Forum: Hybridization
- Topic: Test 2 Topics
- Replies: 11
- Views: 660
Re: Test 2 Topics
I'm pretty sure it's everything we covered after the midterm up until but not including hybridization.
- Fri Nov 08, 2019 2:16 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Monday Lecture
- Replies: 2
- Views: 140
Monday Lecture
Since we don't have school on Monday, is there anything we need to prepare for the Friday lecture or no?
- Fri Nov 08, 2019 2:04 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Test 2
- Replies: 6
- Views: 379
Test 2
Does anybody know when Test 2 will be?
- Fri Nov 08, 2019 2:03 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Hydrogen bonding specificity
- Replies: 3
- Views: 160
Hydrogen bonding specificity
Why do hydrogen bonds only form between N, F and O? Why do they not form with elements in lower periods?
- Fri Nov 08, 2019 1:59 pm
- Forum: Interionic and Intermolecular Forces (Ion-Ion, Ion-Dipole, Dipole-Dipole, Dipole-Induced Dipole, Dispersion/Induced Dipole-Induced Dipole/London Forces, Hydrogen Bonding)
- Topic: Interaction potential energy equations
- Replies: 1
- Views: 131
Interaction potential energy equations
Can someone explain how the interaction potential energy equations for different types of bonds work? I know that r is distance and alpha is polarizability, but how do the two interact to form the potential energy? Also, in what context would these equations be used?
- Mon Nov 04, 2019 11:14 am
- Forum: *Shrodinger Equation
- Topic: Explanation of Shrodinger Equation and Hamiltonian
- Replies: 3
- Views: 325
Explanation of Shrodinger Equation and Hamiltonian
What do we need to understand conceptually about the Shrodinger equation and the Hamiltonian? How do these concepts interact, and do we need to know the equation/how to solve the Hamiltonian?
- Sun Nov 03, 2019 10:35 pm
- Forum: Photoelectric Effect
- Topic: Dino Nuggets 8a
- Replies: 1
- Views: 100
Dino Nuggets 8a
At the review session on Friday, we went over 8a on the Dino Nuggets packet and found an equation derived from E(photon) = (threshold) + E(kinetic) that was equalled to frequency. Why did the equation need to be equalled to frequency? Could any other form of this equation still work to show the cons...
- Fri Nov 01, 2019 7:49 pm
- Forum: Ionic & Covalent Bonds
- Topic: Covalent character in ionic bonds
- Replies: 3
- Views: 140
Covalent character in ionic bonds
If a bond is ionic, why would it have more or less covalent character? Is this because the electron being pulled on by the cation has more or less polarizing power/the anion has more or less polarizability?
- Fri Nov 01, 2019 7:46 pm
- Forum: Polarisability of Anions, The Polarizing Power of Cations
- Topic: Distorted electrons
- Replies: 2
- Views: 152
Distorted electrons
Exactly what does it mean for an electron to be distorted?
- Fri Nov 01, 2019 7:44 pm
- Forum: Sigma & Pi Bonds
- Topic: Significance of sigma and pi bonds
- Replies: 4
- Views: 275
Significance of sigma and pi bonds
Exactly what is a sigma and pi bond, and how do we know which molecules have which type of bond?
- Fri Nov 01, 2019 7:23 pm
- Forum: Octet Exceptions
- Topic: What are these?
- Replies: 3
- Views: 143
What are these?
Exactly what are the elements that are exceptions to the octet rule?
- Fri Nov 01, 2019 7:14 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Formal charge purpose
- Replies: 40
- Views: 6983
Re: Formal charge purpose
Compounds naturally want to be at their most stable form. By using formal charges and equalling them to 0, we are better able to find what is ACTUALLY the most stable structure of the compound so that we know what the structure of the compound actually is in nature.
- Sun Oct 20, 2019 8:28 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Exceptions to Orbital Rules
- Replies: 8
- Views: 1376
Exceptions to Orbital Rules
What are the exceptions to the orbital rules we went over in class? I vaguely remember that d5 and d10 have different energy values so their orbital sequences are different.
- Sun Oct 20, 2019 8:25 pm
- Forum: *Particle in a Box
- Topic: Explaining Particle in a Box
- Replies: 4
- Views: 452
Explaining Particle in a Box
I don't know if I just didn't label it down in my notes but I am not completely sure what this experiment entails. Would someone be able to explain particle in a box to me?
- Sun Oct 20, 2019 8:23 pm
- Forum: *Black Body Radiation
- Topic: Understanding Black Body Radiation
- Replies: 8
- Views: 666
Understanding Black Body Radiation
Exactly what is black body radiation, and what do I need to know about it?
- Sun Oct 20, 2019 8:19 pm
- Forum: Properties of Light
- Topic: Wave Properties of Sound
- Replies: 4
- Views: 194
Wave Properties of Sound
Just curious, would wave properties such as constructive and destructive interference apply to things other than light, like sound? If so, what would be an example of that?