Search found 51 matches

by Sophia Bozone 2G
Tue Mar 13, 2018 9:32 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Chapter 15.12?
Replies: 4
Views: 160

Chapter 15.12?

Online it says we will be tested all of chapter 15 excluding 15.9, however 15.12 is quite confusing and contains some equations that I don't recall looking at. What do you think I should know?
by Sophia Bozone 2G
Tue Mar 13, 2018 7:20 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Steady-State v Pre equilibrium?
Replies: 2
Views: 125

Steady-State v Pre equilibrium?

What is the difference between "imposing the steady-state approximation" and "assuming that there is a pre-equiibrium" for determining rate laws?
by Sophia Bozone 2G
Sun Mar 11, 2018 10:28 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Pre-equiliibrium?
Replies: 3
Views: 159

Pre-equiliibrium?

the textbook says: "A rate law is often derived from a proposed mechanism by imposing the steady-state approximation or assuming that there is a pre-equilibrium." What is meant by "there is a pre-equilibrium?"
by Sophia Bozone 2G
Sun Mar 11, 2018 8:07 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Steady State Approximation?
Replies: 2
Views: 103

Steady State Approximation?

What is the steady state approximation and what are it's impacts?
by Sophia Bozone 2G
Sun Mar 11, 2018 7:37 pm
Forum: First Order Reactions
Topic: Slope of 1st order RXNs
Replies: 9
Views: 409

Slope of 1st order RXNs

Is the slope of 1st order reactions +k or -k, and what is time graphed against in terms of [A]?
by Sophia Bozone 2G
Sun Mar 11, 2018 7:35 pm
Forum: Zero Order Reactions
Topic: Half-Life of Zero Order
Replies: 3
Views: 250

Half-Life of Zero Order

Next to the half life equation for zero order reactions i the text book it says that the equation isn't used. Do you know why this is? It also has that written next to the Second order half life equation but we were asked about that on Test #3. Should i assume that this is fair game as well?
by Sophia Bozone 2G
Sun Mar 11, 2018 7:30 pm
Forum: Zero Order Reactions
Topic: Pseudo Zero Order Reactions
Replies: 3
Views: 405

Re: Pseudo Zero Order Reactions

I don't believe it is possible to have a zero order reaction. This is when one or more reactants is kept in such high quality that the r relative concentration hardly change during the reaction. If you did this to all the reactants to get something like a pseudo zero order, then they would all chang...
by Sophia Bozone 2G
Sun Mar 11, 2018 7:14 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Molar Entropy
Replies: 9
Views: 425

Re: Molar Entropy

Yes, the larger a molecule is, the larger it's molar entropy. This is because a larger molecule has more possible substates, positions, or orientations. It's degeneracy is higher. For example, a linear molecule can have two possible orientations, whereas a trigonal planar molecule could have more.
by Sophia Bozone 2G
Sun Mar 11, 2018 7:12 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: Slowest Step
Replies: 3
Views: 149

Re: Slowest Step

Its just like a limiting reactant problem form fundamentals of 14A. The amount of product that can be made relies on the limiting reactant based on the molar ratios. In the same way, the slowest step limits the rate of the reaction.
by Sophia Bozone 2G
Sun Mar 11, 2018 5:56 pm
Forum: Method of Initial Rates (To Determine n and k)
Topic: Negative Order
Replies: 7
Views: 765

Re: Negative Order

Conceptually, a reaction with a negative order means that as you increase the concentration of reactant, the reaction rate actually decreases. This seems to eb an interesting phenomena to me, and I 'm sent sure of any real life examples of it.
by Sophia Bozone 2G
Sun Mar 11, 2018 5:54 pm
Forum: Balancing Redox Reactions
Topic: redox
Replies: 6
Views: 223

Re: redox

Its kind of a backwards terminology. If you follow the flow of electrons, the particles being oxidized are the reducing agents, and the particles being reduced are the oxidizing agents.
by Sophia Bozone 2G
Tue Mar 06, 2018 10:56 pm
Forum: First Order Reactions
Topic: pseudo rxn
Replies: 4
Views: 219

Re: pseudo rxn

A pseudo 1st order reaction means that the reaction is actually a second order reaction, but we've set one of the reactants at such a high concentration that the change to it during the reaction is negligible. Thus, because for all intents and purposes only one reactant concentration is changing, it...
by Sophia Bozone 2G
Tue Mar 06, 2018 10:51 pm
Forum: General Rate Laws
Topic: Proper units
Replies: 7
Views: 234

Re: Proper units

It shouldn't matter what units your answer is in.
by Sophia Bozone 2G
Tue Mar 06, 2018 10:50 pm
Forum: Zero Order Reactions
Topic: Test 3
Replies: 1
Views: 212

Re: Test 3

The negative orders might appear on the test, while fractional will not. Yes, you can get both from the trials. For example, if the rate changes from 20 to 10, when [a] doubles, it means it is -1 in A. This is an answer from Chem mod on that topic in response to a previous question. In other words,...
by Sophia Bozone 2G
Tue Mar 06, 2018 10:48 pm
Forum: First Order Reactions
Topic: Negative Order RXN?
Replies: 2
Views: 135

Negative Order RXN?

What does it mean if a reaction has a negative order?
by Sophia Bozone 2G
Tue Mar 06, 2018 10:44 pm
Forum: First Order Reactions
Topic: k
Replies: 16
Views: 581

Re: k

I don't think the math of the problem is messed up, simply on a logistics level, when a different unit is used. its all about keeping track of your units. Also it will be easier to keep the units the same as the units of the answer you are trying to find
by Sophia Bozone 2G
Tue Mar 06, 2018 10:42 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Increasing Concentration of Reactants
Replies: 5
Views: 273

Re: Increasing Concentration of Reactants

yes, the reactions we are dealing with have a favorable forward reaction, and because we are typically dealing with them from the beginning of the reaction, they have not yet hit equilibrium. Therefore, an increase in reactants will increase the rate of the reaction
by Sophia Bozone 2G
Sun Mar 04, 2018 7:31 pm
Forum: General Rate Laws
Topic: Naming Clarification
Replies: 3
Views: 130

Naming Clarification

Is a Differential rate law the same thing as an Instantaneous rate law?
Thank you
by Sophia Bozone 2G
Mon Feb 26, 2018 10:57 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Standard Potential
Replies: 4
Views: 163

Re: Standard Potential

As far as I can tell, pH is specific to solutions, such as an aqueous solution of HCl- at standard pressure and temperature wont be the same as any kind of bases and I'm pretty sure it would be a complicated precess to regulate this. So Im pretty are the answer is no
by Sophia Bozone 2G
Mon Feb 26, 2018 10:53 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Isolated [ENDORSED]
Replies: 3
Views: 304

Re: Isolated [ENDORSED]

An isolated system is defend as a system in which no heat or matter is transferred into/out of. Because of the law of conservation of matter and energy, the amount of matter and energy in the universe is constant and unchanging - thus an isolated system.
by Sophia Bozone 2G
Mon Feb 26, 2018 10:50 pm
Forum: Balancing Redox Reactions
Topic: Half Reaction Order
Replies: 9
Views: 259

Re: Half Reaction Order

An oxidation reaction would have the electrons added (electrons are lost), so they should be on the right side of the arrow. A reduction reaction would have the opposite situation occurring, with electrons being gained so they will be listed on the left side.
by Sophia Bozone 2G
Mon Feb 26, 2018 10:47 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Cell Potential
Replies: 9
Views: 2286

Re: Cell Potential

These equations can be used in the same situation, however the one with a number already in it has been simplified with the entry of variables already.
by Sophia Bozone 2G
Mon Feb 26, 2018 10:46 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Q and K
Replies: 7
Views: 267

Re: Q and K

Q and K are the same in this context as in equilibrium, so the ideas around K>1 (products are favored), Q>K (reactants are favored), Q<K (products favored) are the same
by Sophia Bozone 2G
Fri Feb 02, 2018 8:39 pm
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Residual Molar Entropy?
Replies: 3
Views: 155

Residual Molar Entropy?

Question 9.25 asks about the residual molar entropy of a disordered crystal, and I'm not quite sure what it's asking or how to go about answering the problem.
by Sophia Bozone 2G
Fri Feb 02, 2018 8:28 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Problem 9.19 about Standard Entropy
Replies: 6
Views: 173

Problem 9.19 about Standard Entropy

For problem 9.19, It asks us to calculate the standard entropy of vaporization of water at 85 degrees. The solution of the problem shows that you have to calculate \Delta S of heating the reactants, and then \Delta S of vaporization, but then for some reason it says you have to calculate the entropy...
by Sophia Bozone 2G
Mon Jan 29, 2018 7:59 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Kb=?
Replies: 2
Views: 104

Kb=?

In my notes I have two different definitions of Kb.
I have Kb=(R)(Avogadro's number)
and Kb=(R)(number of moles n)
Which is correct?
by Sophia Bozone 2G
Mon Jan 29, 2018 7:11 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Degeneracy and Entropy
Replies: 3
Views: 151

Degeneracy and Entropy

I am still unsure as to what exactly degeneracy is, and how degeneracy is related to entropy.
by Sophia Bozone 2G
Mon Jan 22, 2018 11:23 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Open System [ENDORSED]
Replies: 4
Views: 169

Re: Open System [ENDORSED]

In a more Laboratory-like setting, an open system could be a glass beaker into which you can place different substances. if you can also place it on some sort of heat source like a bunsen burner or cool it down in addition to the exchange of materials it will be an open system
by Sophia Bozone 2G
Mon Jan 22, 2018 11:14 pm
Forum: Phase Changes & Related Calculations
Topic: Heat capacities
Replies: 5
Views: 178

Re: Heat capacities

Degrees celsius and Kelvin cannot be used interchangeably. One unit of each is indeed equal, but as for the numerical value associated with a temperature, Kelvin is equal to # degrees celsius + 273.15
by Sophia Bozone 2G
Mon Jan 22, 2018 11:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Different Delta H. Question 8.57
Replies: 2
Views: 135

Different Delta H. Question 8.57

In this question, it states a Delta H with a subscript c. What does the C mean?
by Sophia Bozone 2G
Mon Jan 15, 2018 1:43 pm
Forum: Calculating Work of Expansion
Topic: Question 8.11 Reversible v Irreversible actions
Replies: 2
Views: 149

Question 8.11 Reversible v Irreversible actions

In Question 8.11, What is the difference between the (a) and the (b) in which it expands reversible and isothermally?
Thanks
by Sophia Bozone 2G
Mon Jan 15, 2018 1:38 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Units of Pressure
Replies: 3
Views: 190

Units of Pressure

What are all the units of pressure and their conversions? Which unit is not commonly used? Will need to memorize these?
Thanks
by Sophia Bozone 2G
Mon Jan 15, 2018 1:34 pm
Forum: Phase Changes & Related Calculations
Topic: Types of Systems
Replies: 10
Views: 380

Types of Systems

What is the difference between a closed and isolated system?
Thanks!
by Sophia Bozone 2G
Sun Dec 03, 2017 9:43 pm
Forum: Naming
Topic: Naming Coordination Compounds
Replies: 8
Views: 321

Re: Naming Coordination Compounds

If your transition metal (or central atom) is contained in the anion part of the compound, -ate will be added
by Sophia Bozone 2G
Sun Dec 03, 2017 9:27 pm
Forum: Hybridization
Topic: Pi Bonds
Replies: 2
Views: 165

Re: Pi Bonds

It is related to the idea of resonance structures. If a molecule can have a pi bond in multiple places, we know that it does not actually have different kinds of bonds, but rather, all the bonds are an average of all the bonds in the structure. This can be seen in Benzene. So because one pi bond is ...
by Sophia Bozone 2G
Sun Nov 26, 2017 7:20 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: 4.43
Replies: 2
Views: 153

4.43

I don't quite understand what s-character means, and why bond angles increases as s-character increases. Could someone try to explain the to me?
by Sophia Bozone 2G
Sun Nov 26, 2017 7:17 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Sigma and Pi bonds
Replies: 2
Views: 154

Sigma and Pi bonds

I understand that a double bond will be comprised of a sigma and pi bond, but I don't understand the hybridization and orbitals that prove that. Could do someone explain it?
by Sophia Bozone 2G
Sun Nov 19, 2017 11:35 pm
Forum: Einstein Equation
Topic: Use of symbols
Replies: 6
Views: 628

Re: Use of symbols

If it helps, you could write out the whole problem in a way that you are comfortable with, and then change your variable afterwards.
by Sophia Bozone 2G
Sun Nov 19, 2017 2:11 pm
Forum: Naming
Topic: Terminology
Replies: 4
Views: 194

Terminology

For whatever reason, as we've moved into this most current topic, I have been really lost and confused even with the most basic topics. I know this is probably a really dumb question, but what exactly is a ligand, and what is their relevance. Why is it important to be able to recognize a ligand and ...
by Sophia Bozone 2G
Sun Nov 12, 2017 10:57 pm
Forum: Lewis Structures
Topic: Radicals
Replies: 7
Views: 291

Re: Radicals

Most often, yes. With an odd number of electrons, there will be one electron ending up without a pair. Thank you of this illuminating knowledge benevolent sir :-* Why welcome fair kind maiden, hath 14a been treating thee kindly? 14a hath been a journey of the soul, down to my innermost electron (te...
by Sophia Bozone 2G
Sun Nov 12, 2017 10:47 pm
Forum: Lewis Structures
Topic: Radicals
Replies: 7
Views: 291

Re: Radicals

Veronica Rasmusen 1E wrote:Most often, yes. With an odd number of electrons, there will be one electron ending up without a pair.

Thank you of this illuminating knowledge benevolent sir :-*
by Sophia Bozone 2G
Sun Nov 12, 2017 10:39 pm
Forum: Lewis Structures
Topic: double bonds in NO3-
Replies: 2
Views: 183

Re: double bonds in NO3-

Nitrogen will stick pretty closely to the octet rule, and if all the bonds were double bonds, the formal charges would indicate the [censored] would not be the most stable molecule.
by Sophia Bozone 2G
Sun Nov 12, 2017 10:16 pm
Forum: Lewis Structures
Topic: Radicals
Replies: 7
Views: 291

Radicals

Can you assume a molecule will be radical if its atoms have an odd number of valence elctorns between themselves?
by Sophia Bozone 2G
Sun Nov 05, 2017 11:07 pm
Forum: Lewis Structures
Topic: Expanded Octet Rule
Replies: 3
Views: 179

Re: Expanded Octet Rule

Non-metals with a d-subshell are able to have expanded octets. For instance, elements 13-17 can have expanded octets. You’ll know to draw an expanded octet when the central atom is bonded to more than 4 elements. The elements that are metals (transition metals included) will tend to give away electr...
by Sophia Bozone 2G
Sun Nov 05, 2017 11:01 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic vs Covalent Bonds
Replies: 4
Views: 202

Re: Ionic vs Covalent Bonds

Covalent bonds are stronger than ionic bonds
by Sophia Bozone 2G
Sun Oct 29, 2017 10:17 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Test #3 Material [ENDORSED]
Replies: 1
Views: 157

Test #3 Material [ENDORSED]

Will we be tested anything related to the f-orbitals? I'm not sure if there are any special rules regarding the order in which electrons get put in subshells once the f-orbital is thrown in the mix, and I'm not sure if I should spend time figuring it out.
Thanks!
by Sophia Bozone 2G
Sun Oct 29, 2017 9:18 pm
Forum: Ionic & Covalent Bonds
Topic: Study Habits [ENDORSED]
Replies: 8
Views: 468

Re: Study Habits [ENDORSED]

It might not be super helpful,because you asked for online sources, but to study I walk myself through the examples in the book step by step to make sure they make complete sense to me before I try the problems in the book. Sometimes the wording of the problems is confusing , but if i have a good ba...
by Sophia Bozone 2G
Sun Oct 15, 2017 11:00 pm
Forum: Properties of Light
Topic: Intensity
Replies: 3
Views: 191

Re: Intensity

In typical waves, intensity is measured as an increase in amplitude. Amplitude is the height of the waves, or the distance of the crests and troughs of waves from the midpoint or node. However, because light functions as a wave and proton, the amplitude does nothing to increase the amount of energy ...
by Sophia Bozone 2G
Sun Oct 15, 2017 10:51 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 918814

Re: Post All Chemistry Jokes Here

You must be made of Uranium and Iodine...
because all I can see is U and I
by Sophia Bozone 2G
Sun Oct 15, 2017 10:43 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7348
Views: 918814

Re: Post All Chemistry Jokes Here

Q: Why was the mole of oxygen molecules excited when he walked out of the singles bar?
A: He got Avogadro's number!
by Sophia Bozone 2G
Sat Oct 07, 2017 9:18 pm
Forum: SI Units, Unit Conversions
Topic: Significant Figures in relation to molar mass [ENDORSED]
Replies: 4
Views: 3325

Significant Figures in relation to molar mass [ENDORSED]

Should the amount of significant figures given in a value in the problem affect the number of sig figs that I use of the molar mass or should i go as precise as possible? For Example: If I am given a mass with two significant figures and I need to convert that value to moles, should I only use two s...

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