Search found 50 matches

by 204918982
Tue Mar 13, 2018 5:50 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Reaction Mechanism Steps
Replies: 4
Views: 162

Re: Reaction Mechanism Steps

Yes we would have to assume that in order to be able to calculate the rate law
by 204918982
Tue Mar 13, 2018 5:43 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Question 15.51
Replies: 8
Views: 308

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...
by 204918982
Tue Mar 13, 2018 5:35 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Collision Theory
Replies: 1
Views: 86

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
by 204918982
Sat Mar 10, 2018 3:12 pm
Forum: *Enzyme Kinetics
Topic: Chapter 15 [ENDORSED]
Replies: 3
Views: 182

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
by 204918982
Sat Mar 10, 2018 2:57 pm
Forum: Second Order Reactions
Topic: Units of k for orders above 2nd
Replies: 6
Views: 347

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!
by 204918982
Sat Mar 10, 2018 2:46 pm
Forum: Second Order Reactions
Topic: 3rd order?
Replies: 7
Views: 582

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
by 204918982
Sun Mar 04, 2018 4:26 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Quiz 3
Replies: 6
Views: 280

Re: Quiz 3

yes the only problems we will be tested on are from 15.1-15.6
by 204918982
Sun Mar 04, 2018 4:16 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Arrhenius Reaction
Replies: 6
Views: 196

Re: Arrhenius Reaction

No but we don't have to worry about these until the final
by 204918982
Sun Mar 04, 2018 4:02 pm
Forum: General Rate Laws
Topic: Rate Law
Replies: 3
Views: 147

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
by 204918982
Fri Feb 23, 2018 2:31 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell diagram [ENDORSED]
Replies: 4
Views: 169

Re: Cell diagram [ENDORSED]

you use a single line because they are different states
by 204918982
Fri Feb 23, 2018 2:27 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Spontaneous Directions [ENDORSED]
Replies: 7
Views: 257

Re: Spontaneous Directions [ENDORSED]

standard potential has to be positive for the reaction to be spontaneous
by 204918982
Fri Feb 23, 2018 2:21 pm
Forum: General Rate Laws
Topic: Negative sign in reactants
Replies: 6
Views: 1096

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
by 204918982
Sun Feb 18, 2018 5:22 pm
Forum: Balancing Redox Reactions
Topic: Bruincast
Replies: 4
Views: 212

Re: Bruincast

I just checked that link and the class that is bruincasted is not Lavelle's
by 204918982
Sun Feb 18, 2018 3:49 pm
Forum: Balancing Redox Reactions
Topic: Test 2
Replies: 5
Views: 180

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
by 204918982
Sat Feb 10, 2018 7:51 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: When to use + sign
Replies: 11
Views: 380

Re: When to use + sign

So should we always put a + sign on positive answers for change calculations on tests/exams?
by 204918982
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: 125

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.
by 204918982
Sat Feb 10, 2018 6:07 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: 9.13
Replies: 4
Views: 129

Re: 9.13

Yes I think that's what we are supposed to use when it says to assume ideal behavior
by 204918982
Thu Feb 01, 2018 11:31 am
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Total Enthalpy
Replies: 2
Views: 133

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
by 204918982
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: 114

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.
by 204918982
Wed Jan 31, 2018 1:40 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Homework 9.55
Replies: 2
Views: 102

Re: Homework 9.55

Yes I think that's what we are supposed to do.
by 204918982
Sun Jan 28, 2018 5:00 pm
Forum: Phase Changes & Related Calculations
Topic: Combustion of liquids
Replies: 4
Views: 201

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
by 204918982
Sun Jan 28, 2018 4:49 pm
Forum: Phase Changes & Related Calculations
Topic: 8.40
Replies: 4
Views: 170

Re: 8.40

I got that same answer as well
by 204918982
Sat Jan 27, 2018 5:11 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Units for Entropy
Replies: 4
Views: 143

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.
by 204918982
Fri Jan 19, 2018 2:06 pm
Forum: Calculating Work of Expansion
Topic: 8.13
Replies: 2
Views: 78

Re: 8.13

The cylinder itself is losing energy so the heat is negative
by 204918982
Fri Jan 19, 2018 2:03 pm
Forum: Calculating Work of Expansion
Topic: units for calculating work
Replies: 6
Views: 132

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.
by 204918982
Thu Jan 18, 2018 9:15 pm
Forum: Calculating Work of Expansion
Topic: Question 8.27 Conversion
Replies: 2
Views: 131

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.
by 204918982
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: 102

Re: Delta H and Delta U

Yes this is only true when the pressure and volume are constant
by 204918982
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: 177

Re: Homework help on 8.29

So thinking in terms of which one has more bonds is incorrect?
by 204918982
Sun Jan 14, 2018 1:40 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Not a State Property
Replies: 6
Views: 180

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
by 204918982
Thu Dec 07, 2017 5:12 pm
Forum: Bronsted Acids & Bases
Topic: Bronsted vs. Lewis
Replies: 4
Views: 237

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.
by 204918982
Thu Dec 07, 2017 5:03 pm
Forum: Hybridization
Topic: Lone Pairs in Hybridization
Replies: 4
Views: 291

Re: Lone Pairs in Hybridization

lone pairs are included and double/triple bonds are only counted as one area of electron density
by 204918982
Fri Dec 01, 2017 5:00 pm
Forum: Ideal Gases
Topic: Q and K [ENDORSED]
Replies: 35
Views: 1177

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.
by 204918982
Fri Dec 01, 2017 4:56 pm
Forum: Ideal Gases
Topic: Units for the formula
Replies: 4
Views: 386

Re: Units for the formula

What does the R stand for again?
by 204918982
Wed Nov 22, 2017 6:19 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bent vs. Angular
Replies: 5
Views: 335

Re: Bent vs. Angular

Yes, they mean the same thing.
by 204918982
Wed Nov 22, 2017 6:00 pm
Forum: Naming
Topic: 17.29 Cobalt vs. Colbaltate
Replies: 3
Views: 173

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.
by 204918982
Sat Nov 18, 2017 4:56 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Understanding sigma and pi bonds?
Replies: 8
Views: 324

Re: Understanding sigma and pi bonds?

why can't pi bonds rotate?
by 204918982
Sat Nov 18, 2017 4:35 pm
Forum: Hybridization
Topic: Hybridization in Carbon
Replies: 3
Views: 138

Re: Hybridization in Carbon

Any bond (single, double, or triple) only counts as one region of electron density.
by 204918982
Fri Nov 10, 2017 10:54 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Drawing the configuration
Replies: 4
Views: 218

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.
by 204918982
Fri Nov 10, 2017 10:44 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Sulfur Dioxide?
Replies: 3
Views: 271

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.
by 204918982
Fri Nov 03, 2017 7:53 pm
Forum: Ionic & Covalent Bonds
Topic: How to easily tell between Ionic and Covalent bonds?
Replies: 8
Views: 459

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.
by 204918982
Fri Nov 03, 2017 7:48 pm
Forum: Ionic & Covalent Bonds
Topic: Noble Gases
Replies: 6
Views: 423

Re: Noble Gases

Yes they still can form compounds, but under extreme circumstances.
by 204918982
Fri Oct 27, 2017 9:28 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Px, Py, Pz
Replies: 10
Views: 547

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
by 204918982
Fri Oct 27, 2017 8:15 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: d and s blocks
Replies: 16
Views: 721

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
by 204918982
Thu Oct 19, 2017 10:05 pm
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: Rydberg Equation
Replies: 7
Views: 372

Re: Rydberg Equation

n1 is always the ending energy level: E(final)-E(initial)
by 204918982
Thu Oct 19, 2017 9:38 pm
Forum: Properties of Light
Topic: Color of visible light
Replies: 11
Views: 574

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)
by 204918982
Thu Oct 12, 2017 5:47 pm
Forum: Photoelectric Effect
Topic: Energy in kj or j when solving a problem?
Replies: 10
Views: 573

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.
by 204918982
Thu Oct 12, 2017 5:14 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect Module Question 18 [ENDORSED]
Replies: 3
Views: 249

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.
by 204918982
Thu Oct 05, 2017 8:52 pm
Forum: Limiting Reactant Calculations
Topic: Percent Yield [ENDORSED]
Replies: 5
Views: 598

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.
by 204918982
Thu Oct 05, 2017 8:35 pm
Forum: Empirical & Molecular Formulas
Topic: Problem E5
Replies: 6
Views: 1116

Re: Problem E5

Yes I got those answers too and I checked them in the solutions manual :)

Go to advanced search