Search found 50 matches
- Tue Mar 13, 2018 5:50 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Reaction Mechanism Steps
- Replies: 4
- Views: 575
Re: Reaction Mechanism Steps
Yes we would have to assume that in order to be able to calculate the rate law
- Tue Mar 13, 2018 5:43 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Question 15.51
- Replies: 8
- Views: 1032
Re: Question 15.51
can someone elaborate on what the solutions manual is talking about when we say that the second elementary reaction is fast and it does not affect the reaction order?? the rate law is determined by the slowest elementary step, which is step 1 in this case, so step 2 doesn't have any effect on it be...
- Tue Mar 13, 2018 5:35 pm
- Forum: Reaction Mechanisms, Reaction Profiles
- Topic: Collision Theory
- Replies: 1
- Views: 265
Re: Collision Theory
This is section 15.12 of the textbook which is one of the sections that we are responsible for knowing according to the syllabus, but I don't think we have covered it in class
- Sat Mar 10, 2018 3:12 pm
- Forum: *Enzyme Kinetics
- Topic: Chapter 15 [ENDORSED]
- Replies: 3
- Views: 611
Re: Chapter 15 [ENDORSED]
yes according to the syllabus we are responsible for knowing all of 15.1 to 15.15, except 15.9, for the final
- Sat Mar 10, 2018 2:57 pm
- Forum: Second Order Reactions
- Topic: Units of k for orders above 2nd
- Replies: 6
- Views: 893
Re: Units of k for orders above 2nd
Yes I'm pretty sure this will always work, I've never thought about it like this so thanks for the tip!
- Sat Mar 10, 2018 2:46 pm
- Forum: Second Order Reactions
- Topic: 3rd order?
- Replies: 7
- Views: 1230
Re: 3rd order?
If you don't remember the units for k for certain orders you can always just divide the rate by the concentration. For 3rd order reactions, the units are (M/s)(1/M^3) which simplifies to (1/M^2)s
- Sun Mar 04, 2018 4:26 pm
- Forum: Method of Initial Rates (To Determine n and k)
- Topic: Quiz 3
- Replies: 6
- Views: 861
Re: Quiz 3
yes the only problems we will be tested on are from 15.1-15.6
- Sun Mar 04, 2018 4:16 pm
- Forum: Arrhenius Equation, Activation Energies, Catalysts
- Topic: Arrhenius Reaction
- Replies: 6
- Views: 832
Re: Arrhenius Reaction
No but we don't have to worry about these until the final
- Sun Mar 04, 2018 4:02 pm
- Forum: General Rate Laws
- Topic: Rate Law
- Replies: 3
- Views: 503
Re: Rate Law
The concentration of reactants is negative so there needs to be a negative sign to cancel it out and make the rate positive
- Fri Feb 23, 2018 2:31 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Cell diagram [ENDORSED]
- Replies: 4
- Views: 635
Re: Cell diagram [ENDORSED]
you use a single line because they are different states
- Fri Feb 23, 2018 2:27 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: Spontaneous Directions [ENDORSED]
- Replies: 7
- Views: 1046
Re: Spontaneous Directions [ENDORSED]
standard potential has to be positive for the reaction to be spontaneous
- Fri Feb 23, 2018 2:21 pm
- Forum: General Rate Laws
- Topic: Negative sign in reactants
- Replies: 6
- Views: 4732
Re: Negative sign in reactants
There will always be a negative sign in front of the reactants in order to make the reaction rate positive
- Sun Feb 18, 2018 5:22 pm
- Forum: Balancing Redox Reactions
- Topic: Bruincast
- Replies: 4
- Views: 654
Re: Bruincast
I just checked that link and the class that is bruincasted is not Lavelle's
- Sun Feb 18, 2018 4:39 pm
- Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
- Topic: galvanic cells and voltaic cells
- Replies: 2
- Views: 314
Re: galvanic cells and voltaic cells
Yes, they are the same
- Sun Feb 18, 2018 3:49 pm
- Forum: Balancing Redox Reactions
- Topic: Test 2
- Replies: 5
- Views: 665
Re: Test 2
I think we will be given a chart with half reactions and their cell potentials and then we will have to come up with the reactions for the specific problem and find them on the chart
- Sat Feb 10, 2018 7:51 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: When to use + sign
- Replies: 11
- Views: 1072
Re: When to use + sign
So should we always put a + sign on positive answers for change calculations on tests/exams?
- Sat Feb 10, 2018 6:11 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 9.47 delta S = 0
- Replies: 2
- Views: 347
Re: 9.47 delta S = 0
Delta S=0 because the amount of heat lost by the system is equal to the amount of heat gained by the surroundings.
- Sat Feb 10, 2018 6:07 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: 9.13
- Replies: 4
- Views: 506
Re: 9.13
Yes I think that's what we are supposed to use when it says to assume ideal behavior
- Thu Feb 01, 2018 11:31 am
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Total Enthalpy
- Replies: 2
- Views: 378
Re: Total Enthalpy
In a reversible reaction, the change in entropy of the system is the negative of the change in entropy of the surroundings, so the total change is zero
- Wed Jan 31, 2018 1:57 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: Box 9.1 Absolute Zero
- Replies: 2
- Views: 329
Re: Box 9.1 Absolute Zero
It's not on our review sheet and he hasn't mentioned it in class, so we probably don't need to memorize it.
- Wed Jan 31, 2018 1:40 pm
- Forum: Gibbs Free Energy Concepts and Calculations
- Topic: Homework 9.55
- Replies: 2
- Views: 360
Re: Homework 9.55
Yes I think that's what we are supposed to do.
- Sun Jan 28, 2018 5:00 pm
- Forum: Phase Changes & Related Calculations
- Topic: Combustion of liquids
- Replies: 4
- Views: 764
Re: Combustion of liquids
It's usually liquid H2O because the temperature of the reactions in our homework problems is stated or assumed to be 25 degrees Celsius
- Sun Jan 28, 2018 4:49 pm
- Forum: Phase Changes & Related Calculations
- Topic: 8.40
- Replies: 4
- Views: 517
Re: 8.40
I got that same answer as well
- Sat Jan 27, 2018 5:11 pm
- Forum: Entropy Changes Due to Changes in Volume and Temperature
- Topic: Units for Entropy
- Replies: 4
- Views: 484
Re: Units for Entropy
Yeah I think the standard units are just J/K and J/K/mol is used when the question asks for the entropy per mole.
- Fri Jan 19, 2018 2:06 pm
- Forum: Calculating Work of Expansion
- Topic: 8.13
- Replies: 2
- Views: 237
Re: 8.13
The cylinder itself is losing energy so the heat is negative
- Fri Jan 19, 2018 2:03 pm
- Forum: Calculating Work of Expansion
- Topic: units for calculating work
- Replies: 6
- Views: 599
Re: units for calculating work
atm and liters would probably be the best units since the conversion of L.atm to joules will be given to us on the constants and formulas sheet.
- Thu Jan 18, 2018 9:15 pm
- Forum: Calculating Work of Expansion
- Topic: Question 8.27 Conversion
- Replies: 2
- Views: 313
Re: Question 8.27 Conversion
This is the conversion of kPa to atm that we have to use in order to get our answer in joules.
- Sun Jan 14, 2018 1:59 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Delta H and Delta U
- Replies: 3
- Views: 221
Re: Delta H and Delta U
Yes this is only true when the pressure and volume are constant
- Sun Jan 14, 2018 1:57 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Homework help on 8.29
- Replies: 4
- Views: 333
Re: Homework help on 8.29
So thinking in terms of which one has more bonds is incorrect?
- Sun Jan 14, 2018 1:40 pm
- Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
- Topic: Heat Not a State Property
- Replies: 6
- Views: 541
Re: Heat Not a State Property
Heat depends on the path that is taken not just its initial and final state, so it is not a state property
- Thu Dec 07, 2017 5:12 pm
- Forum: Bronsted Acids & Bases
- Topic: Bronsted vs. Lewis
- Replies: 4
- Views: 608
Re: Bronsted vs. Lewis
yes, Bronsted acids donate a proton and Bronsted bases accept a proton while Lewis acids accept an electron pair and Lewis bases donate an electron pair.
- Thu Dec 07, 2017 5:03 pm
- Forum: Hybridization
- Topic: Lone Pairs in Hybridization
- Replies: 4
- Views: 736
Re: Lone Pairs in Hybridization
lone pairs are included and double/triple bonds are only counted as one area of electron density
- Fri Dec 01, 2017 5:00 pm
- Forum: Ideal Gases
- Topic: Q and K [ENDORSED]
- Replies: 35
- Views: 3240
Re: Q and K [ENDORSED]
There is no difference between the formulas, but they calculate different things. K is calculated by using the equilibrium concentrations and Q is calculated by using the concentrations at a different time during the reaction.
- Fri Dec 01, 2017 4:56 pm
- Forum: Ideal Gases
- Topic: Units for the formula
- Replies: 4
- Views: 798
Re: Units for the formula
What does the R stand for again?
- Wed Nov 22, 2017 6:19 pm
- Forum: Determining Molecular Shape (VSEPR)
- Topic: Bent vs. Angular
- Replies: 5
- Views: 1009
Re: Bent vs. Angular
Yes, they mean the same thing.
- Wed Nov 22, 2017 6:00 pm
- Forum: Naming
- Topic: 17.29 Cobalt vs. Colbaltate
- Replies: 3
- Views: 510
Re: 17.29 Cobalt vs. Colbaltate
We use cobalt in our answer for b and d because there is a positive charge on the complex and we use cobaltate in our answer for c because the complex has a negative charge.
- Sat Nov 18, 2017 4:56 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Understanding sigma and pi bonds?
- Replies: 8
- Views: 857
Re: Understanding sigma and pi bonds?
why can't pi bonds rotate?
- Sat Nov 18, 2017 4:35 pm
- Forum: Hybridization
- Topic: Hybridization in Carbon
- Replies: 3
- Views: 385
Re: Hybridization in Carbon
Any bond (single, double, or triple) only counts as one region of electron density.
- Fri Nov 10, 2017 10:54 pm
- Forum: Electron Configurations for Multi-Electron Atoms
- Topic: Drawing the configuration
- Replies: 4
- Views: 439
Re: Drawing the configuration
sofiakrylova3j wrote:So technically we don't know if a certain electron has positive or negative spin?
I don't think so. Unless you are given ms= 1/2 or ms= -1/2 then you know it's spin up or spin down.
- Fri Nov 10, 2017 10:44 pm
- Forum: Formal Charge and Oxidation Numbers
- Topic: Sulfur Dioxide?
- Replies: 3
- Views: 643
Re: Sulfur Dioxide?
The two resonance structures can exist because the actual structure is a blend of all three, even though most of the time the sulfur dioxide molecule is in the state of the one with the formal charge of zero.
- Fri Nov 03, 2017 7:53 pm
- Forum: Ionic & Covalent Bonds
- Topic: How to easily tell between Ionic and Covalent bonds?
- Replies: 8
- Views: 1563
Re: How to easily tell between Ionic and Covalent bonds?
I learned this method in high school too and I think it will work in this class, but it might be better to calculate the electronegativity difference.
- Fri Nov 03, 2017 7:48 pm
- Forum: Ionic & Covalent Bonds
- Topic: Noble Gases
- Replies: 6
- Views: 889
Re: Noble Gases
Yes they still can form compounds, but under extreme circumstances.
- Fri Oct 27, 2017 9:28 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: Px, Py, Pz
- Replies: 10
- Views: 1319
Re: Px, Py, Pz
I think he might prefer if we write it in the Px, Py, Pz form but I don't think we'll be penalized if we write it the other way
- Fri Oct 27, 2017 8:15 pm
- Forum: Wave Functions and s-, p-, d-, f- Orbitals
- Topic: d and s blocks
- Replies: 16
- Views: 2224
Re: d and s blocks
the energy of (n)s is greater than (n-1)d so you write the d block before the s block. For example: 3d is written before 4s because the energy of 4s is greater than the energy of 3d
- Thu Oct 19, 2017 10:05 pm
- Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
- Topic: Rydberg Equation
- Replies: 7
- Views: 902
Re: Rydberg Equation
n1 is always the ending energy level: E(final)-E(initial)
- Thu Oct 19, 2017 9:38 pm
- Forum: Properties of Light
- Topic: Color of visible light
- Replies: 11
- Views: 1251
Re: Color of visible light
I think the only ones we are expected to remember for now are red(700 nm) and violet(400 nm) and maybe blue(470nm)
- Thu Oct 12, 2017 5:47 pm
- Forum: Photoelectric Effect
- Topic: Energy in kj or j when solving a problem?
- Replies: 10
- Views: 2079
Re: Energy in kj or j when solving a problem?
Josh Moy 1I wrote:If we have kg or km should we convert to g and m?
If the problem specifically asks you to convert to g or m then you should, but if it doesn't ask you to then I would suggest just keeping the units that you are given in the problem.
- Thu Oct 12, 2017 5:14 pm
- Forum: Photoelectric Effect
- Topic: Photoelectric Effect Module Question 18 [ENDORSED]
- Replies: 3
- Views: 668
Re: Photoelectric Effect Module Question 18 [ENDORSED]
Yes the question is asking for all the conditions that apply so C and D are both right since the energy of the photon can be equal to or greater than the energy needed to remove the electron.
- Thu Oct 05, 2017 8:52 pm
- Forum: Limiting Reactant Calculations
- Topic: Percent Yield [ENDORSED]
- Replies: 5
- Views: 6122
Re: Percent Yield [ENDORSED]
A high percent yield is better because it suggests that there were fewer impurities that occurred during the experiment and can help with the accuracy of calculations.
- Thu Oct 05, 2017 8:35 pm
- Forum: Empirical & Molecular Formulas
- Topic: Problem E5
- Replies: 6
- Views: 3490
Re: Problem E5
Yes I got those answers too and I checked them in the solutions manual :)