Search found 68 matches

by Glenda Marshall DIS 3M
Sun Mar 15, 2015 1:00 pm
Forum: *Alkanes
Topic: Common Names for Final
Replies: 2
Views: 2532

Re: Common Names for Final

Thank you!
by Glenda Marshall DIS 3M
Sun Mar 15, 2015 12:59 pm
Forum: Second Order Reactions
Topic: Linear Graphs
Replies: 5
Views: 4867

Re: Linear Graphs

Oh that totally makes sense! Thank you so much and sorry for the typo!
by Glenda Marshall DIS 3M
Sat Mar 14, 2015 5:05 pm
Forum: *Alkanes
Topic: Common Names for Final
Replies: 2
Views: 2532

Common Names for Final

Is there a specific list of common names that we should know for the final? I know different variations of this question have been answered, but all of them have either said that common names and IUPAC will be accepted or referred to ways to name molecules. I understand the rules for common naming f...
by Glenda Marshall DIS 3M
Thu Mar 12, 2015 10:04 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Change in Enthalpy for an Isothermal Reaction
Replies: 2
Views: 851

Change in Enthalpy for an Isothermal Reaction

Hi!
I am reviewing my notes and I cannot seem to remember why delta H is zero for an irreversible, isothermal expansion. Any help would be appreciated. Thanks!
by Glenda Marshall DIS 3M
Wed Mar 11, 2015 6:40 pm
Forum: *Cyclohexanes (Chair, Boat, Geometric Isomers)
Topic: Newman Projection down the C-2, C-3 Bond
Replies: 2
Views: 4161

Newman Projection down the C-2, C-3 Bond

Homework problem #3.8 in the yellow organic chemistry book says: "Using a Newman Projection, draw the most stable conformation of a hexane looking down the C2-C3 bond. What is this conformation called and give its dihedral angle." I used my model kit to make a chair cyclohexane and it look...
by Glenda Marshall DIS 3M
Wed Mar 11, 2015 6:30 pm
Forum: Second Order Reactions
Topic: Linear Graphs
Replies: 5
Views: 4867

Re: Linear Graphs

My apologies! Homework problem #14.103 says "which of the following plots would be linear?" and one of the options is "the half-life against [A] for a second order reaction in [A]" I am confused why this is not linear because I thought it would be, but the solutions manual does n...
by Glenda Marshall DIS 3M
Wed Mar 11, 2015 5:08 pm
Forum: Second Order Reactions
Topic: Linear Graphs
Replies: 5
Views: 4867

Linear Graphs

Why is the graph of the half-life of a second order reaction not linear. Wouldn't the slope be 1/k with the variable being [R]o?

Thanks!
by Glenda Marshall DIS 3M
Wed Mar 11, 2015 5:06 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Comparing reducing agents
Replies: 5
Views: 851

Re: Comparing reducing agents

That makes sense, but I am still confused how you know to use

Cu+ + e- ---> Cu Eo =+0.52

as opposed to

Cu2+ + 2e- ---> Cu Eo = +0.34

Because using the lower one would change the answer. Thanks!
by Glenda Marshall DIS 3M
Tue Mar 10, 2015 9:59 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Comparing reducing agents
Replies: 5
Views: 851

Comparing reducing agents

In problem 13.25, it asks us to rank the metals given in order of the power of the reducing agent. Part (a) gives us Cu, Zn, Fe, and Cr. I know that the lower the reduction potential the more powerful the reducing agent, but how do we know which reduction potentials to look at to compare their relat...
by Glenda Marshall DIS 3M
Tue Mar 10, 2015 9:40 pm
Forum: Balancing Redox Reactions
Topic: How to know products if given reactants
Replies: 2
Views: 548

How to know products if given reactants

Hello!
Homework problem #13.17 asks us to

"write the balanced half-reactions for the redox reaction of an acidified solution of potassium permanganate and iron (II) chloride."

How would you know how to write the half reactions when they only give you the reactants? Thanks!
by Glenda Marshall DIS 3M
Mon Mar 09, 2015 9:06 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Polarized diatomic molecules
Replies: 2
Views: 561

Re: Polarized diatomic molecules

Thank you so much!
by Glenda Marshall DIS 3M
Mon Mar 09, 2015 4:51 pm
Forum: *Electrophilic Addition
Topic: Are all electrophilic additions exothermic?
Replies: 2
Views: 1791

Are all electrophilic additions exothermic?

Homework problem 4.29 says "draw and label the reaction profile with potential energy as the y-axis for the electrophilic addition reaction of hydrogen bromide, HBr, to propene, CH3CHCH2, producing 2-bromopropane, CH3CHBrCH3" the graph they drew was an exothermic reaction and I am wonderin...
by Glenda Marshall DIS 3M
Mon Mar 09, 2015 3:15 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Catalysts and the Standard Entropy of Activation
Replies: 2
Views: 744

Catalysts and the Standard Entropy of Activation

I know that a catalyst reduces the free energy of activation by weakening bonds and thus lowers the standard enthalpy of activation, but how does it raise the standard entropy of activation? The wording the in the book is confusing to me. Thank you!
by Glenda Marshall DIS 3M
Mon Mar 09, 2015 2:50 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Polarized diatomic molecules
Replies: 2
Views: 561

Polarized diatomic molecules

Hello! On page 79 of the course reader, there is an example of nucleophiles and electrophiles interacting in which there is a polarized Br2 molecule. I thought that we learned in Chem 14A that diatomic molecules cannot be polarized, so I am wondering how this is possible. Thank you!
by Glenda Marshall DIS 3M
Sun Mar 08, 2015 10:15 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: How many electrons are transferred?
Replies: 1
Views: 7936

How many electrons are transferred?

Hi! On the midterm, question 8 part c) asked how many electrons were transferred in the reaction C6H12O6 + 6O2 ---> 6H2O + 6CO2 The answer is 24 and I understand that each side has a charge of negative 4 so 4 electrons must be involved, but why do they multiply by 6? I can see that the coefficients ...
by Glenda Marshall DIS 3M
Sun Mar 01, 2015 3:06 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Where do bonds form?
Replies: 3
Views: 650

Where do bonds form?

I am slightly confused how to know where bonds form in organic reaction mechanisms. For example, if we look at the reaction between propene, CH3CHCH2, and hydrogen bromide, HBr, how do you know which carbon the hydrogen bonds with once the sigma bond between H and Br breaks? The answer key shows it ...
by Glenda Marshall DIS 3M
Tue Feb 24, 2015 10:19 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Reactants that don't play a part in the reaction
Replies: 2
Views: 625

Reactants that don't play a part in the reaction

In question #14.85 part (b), it asks to write the overall react with the rate law rate=k[I]^2[Ar] (products are I2 and Ar; the role of Ar is to remove energy as the product forms). The reaction they gave was 2I ----> I2 How do we know to exclude the Ar and why would it be a termolecular elementary r...
by Glenda Marshall DIS 3M
Tue Feb 24, 2015 10:15 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Drawing proposed structures for an activated complex
Replies: 3
Views: 1881

Drawing proposed structures for an activated complex

Can someone please explain how to draw a proposed stucture for an activated complex. Question #14.85 asks us to do this and I don't know where to start. The rate laws they gave are: a) rate=k[CH3CHO] products are CH3 and CHO b) rate=k[I]^2[Ar] products are I2 and Ar, the role of the Ar is to remove ...
by Glenda Marshall DIS 3M
Fri Feb 20, 2015 10:04 pm
Forum: General Rate Laws
Topic: When to include H2O in the rate law
Replies: 2
Views: 3623

When to include H2O in the rate law

Question #14.105 gives the following section mechanism: ClO- + H2O ----> HClO + OH- (fast) HClO + I- ----> HIO + Cl- (slow) HIO + OH- ----> IO- + H2O (fast) and asks for the rate law. By using the pre-equilibrium process, I wrote the rate law as [ClO-][H2O][I-] / [OH-] The solutions manual has the s...
by Glenda Marshall DIS 3M
Fri Feb 20, 2015 9:16 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Substituting time for k
Replies: 2
Views: 7335

Re: Substituting time for k

That was so unbelievably helpful! Thank you!
by Glenda Marshall DIS 3M
Fri Feb 20, 2015 8:18 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: Substituting time for k
Replies: 2
Views: 7335

Substituting time for k

Hello! Problem #14.93 in the textbook says "Raw milk sours in about 4 hours at 28 degrees celsius but in about 48 hours in a fridge at 5 degrees celsius. What is the activation energy for the souring of milk?" When I looked at this problem I knew I had to use the Arrhenius Equation compari...
by Glenda Marshall DIS 3M
Tue Feb 10, 2015 4:48 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Quiz One Reversible Heat Exchange
Replies: 1
Views: 480

Quiz One Reversible Heat Exchange

A question on quiz one said "calculate the entropy when 65.7 g of xenon gas undergoes isothermal expansion from an initial pressure of .50 atm to a final pressure of 1.5 atm. Assume that xenon behaves as an ideal gas." I understand how to do this, but what confused me is that it then asked...
by Glenda Marshall DIS 3M
Sat Feb 07, 2015 6:50 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Calculating Q and K using Pressure and Concentration
Replies: 3
Views: 1557

Calculating Q and K using Pressure and Concentration

I remember from thermodynamics that you cannot use both concentrations and parietal pressures when calculating equilibrium constants which is why we always either calculated Kp or Kc. Why can we now use both of them when calculating K and Q for redox reactions? For example, in homework #13.41 the so...
by Glenda Marshall DIS 3M
Sat Feb 07, 2015 5:18 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Finding Vapor Pressure of Liquid (HW #10.109)
Replies: 2
Views: 1106

Finding Vapor Pressure of Liquid (HW #10.109)

What does it mean to find vapor pressure of a liquid? In problem #10.109 in the homework, part (b) asks "what is the vapor pressure of liquid bromine?" and it does not provide an equation or any other information. It the solutions manual, they solved for K and used that value as the vapor ...
by Glenda Marshall DIS 3M
Wed Feb 04, 2015 11:05 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: General Confusion on Homework Problem #13.103
Replies: 2
Views: 542

General Confusion on Homework Problem #13.103

Hi! Can someone please explain homework problem #13.103. The question is: Use data in appendix 2B and the fact that, for the half reaction F2 +2H+ +2e- --> 2HF the standard potential is +3.03 V, to calculate the value of Ka for HF. I don't know how to find the half reactions for this reaction or how...
by Glenda Marshall DIS 3M
Wed Feb 04, 2015 10:57 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Effect of adding a base to solution in a cathode
Replies: 1
Views: 369

Effect of adding a base to solution in a cathode

In homework problem 13.99, the question says that there is a concentration cell with one half cell containing 1.0 M CrCl3 and the other with .001 M CrCl3. It then asks what would happen after adding 100 mL 1.0M NaOH to the cathode if Cr(OH3) is insoluble. The solution says that the NaOH precipitates...
by Glenda Marshall DIS 3M
Wed Feb 04, 2015 10:52 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Effect of adding mass to an electrode (problem 13.99)
Replies: 1
Views: 423

Effect of adding mass to an electrode (problem 13.99)

I am wondering why increasing the mass of an electrode in an anode compartment has no effect of the concentration of the anode solution. Wouldn't more metal decompose thus creating a higher molarity solution in the anode compartment?

Thanks!
by Glenda Marshall DIS 3M
Wed Feb 04, 2015 10:43 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Writing a Half Reaction from a word problem (Homework #13.17
Replies: 4
Views: 1885

Writing a Half Reaction from a word problem (Homework #13.17

If given a word problem that only tells you what you start with in a reaction, how do you know what the reduced and oxidized forms of the ions given are? For example homework 13.17 says "Write the balanced half reactions for the redox reaction of an acidified solution of potassium permanganate ...
by Glenda Marshall DIS 3M
Wed Feb 04, 2015 10:27 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: How to write Half-Reactions with H2O, H+, and OH-
Replies: 1
Views: 18197

How to write Half-Reactions with H2O, H+, and OH-

How do you know the proper equation when H2O, H+, and OH- are involved? For example, in homework problem #13.11 part (d), the following cell diagram is given: Pt l O2 l H+ ll OH- l O2 l Pt In this case, the half reactions are O2 + 2H2O +4e- --> 4 OH- O2 + 4H+ +4e- -->2H2O How would you know that O2 ...
by Glenda Marshall DIS 3M
Wed Feb 04, 2015 10:20 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Writing half reactions from a cell diagram
Replies: 2
Views: 468

Writing half reactions from a cell diagram

I was wondering if someone can help me understand the process of writing half-reactions from cell diagrams. My main question is if there is particular order that the species are written in. I know that the anode will be to the left of the salt bridge (the double line) and the cathode will be to the ...
by Glenda Marshall DIS 3M
Mon Jan 26, 2015 1:56 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Why do you want a negative Gibbs Free Energy
Replies: 1
Views: 791

Why do you want a negative Gibbs Free Energy

I am slightly confused why you want a negative Gibbs Free Energy if Free Energy is the energy available to do work. Wouldn't the more energy you have be better. For example, wouldn't a reaction be more favorable if the products had more free energy than the reactants? In this case the delta G would ...
by Glenda Marshall DIS 3M
Sun Jan 25, 2015 1:03 am
Forum: Calculating Standard Reaction Entropies (e.g. , Using Standard Molar Entropies)
Topic: Homework #8.37
Replies: 2
Views: 1099

Homework #8.37

In this problem, its asks which has a greater change in entropy: 1 mol of an ideal monatomic gas or 1 mol of diatomic molecules that are vibrationally active. Why does the 1 mol of a monatomic gas have a greater change in entropy when the diatomic molecules are more complex? I thought that the more ...
by Glenda Marshall DIS 3M
Sun Jan 25, 2015 12:59 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Homework #8.83
Replies: 1
Views: 338

Homework #8.83

In this homework problem, why did the solution manual write an equation and solve for the delta G? Couldn't they just use the delta G of formation for each of the compounds (like they did in problem 61)? What is the difference between these two problems that suggests different routes of answering th...
by Glenda Marshall DIS 3M
Sun Jan 25, 2015 12:57 am
Forum: Gibbs Free Energy Concepts and Calculations
Topic: #8.93
Replies: 1
Views: 396

#8.93

For homework problem #8.93, why are the answers in kJ and not kJ/mol. Also, I know Dr. Lavelle talked about this in class, but why is the delta G zero at the boiling point? Thank you!
by Glenda Marshall DIS 3M
Fri Jan 23, 2015 4:38 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Total Entropy Change for Irreversible Reactions
Replies: 1
Views: 477

Total Entropy Change for Irreversible Reactions

In example 8.12, it talks about isothermal, free expansion. If the change in entropy of the surroundings is zero because work and change in internal energy are zero, where does the heat that goes into the system come from?
by Glenda Marshall DIS 3M
Fri Jan 23, 2015 4:29 pm
Forum: Entropy Changes Due to Changes in Volume and Temperature
Topic: Entropy change for reversible processes
Replies: 2
Views: 444

Entropy change for reversible processes

Why is total change in entropy zero for a reversibly expanding gas?
by Glenda Marshall DIS 3M
Thu Jan 22, 2015 6:37 pm
Forum: Calculating Work of Expansion
Topic: Why do reversible processes do the most work?
Replies: 3
Views: 1948

Why do reversible processes do the most work?

I understand that reversible processes do the most work and that this is what makes them ideal for thermodynamics. I am confused, however, about what makes reversible processes so effective. Why do these processes produce more work than irreversible processes. Thank you!
by Glenda Marshall DIS 3M
Tue Jan 20, 2015 8:21 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Homework Problem #75
Replies: 3
Views: 469

Homework Problem #75

I am very confused by question 7.75. I understand how to use the bond enthalpies to calculate delta H, but why are they subtracting the enthalpy of vaporization?
by Glenda Marshall DIS 3M
Tue Jan 20, 2015 8:18 pm
Forum: Phase Changes & Related Calculations
Topic: What is Delta E?
Replies: 3
Views: 4210

What is Delta E?

In homework problem number 15, it says that delta E is zero. What is delta E and how does that help us determine work?
by Glenda Marshall DIS 3M
Sat Jan 17, 2015 4:45 pm
Forum: Phase Changes & Related Calculations
Topic: Homework Problem #19
Replies: 5
Views: 774

Re: Homework Problem #19

Thank you! That definitely helps! I am still a little confused though because in the solutions manual it says that "heat lost by metal = - heat gained by water. If the water is the surroundings, then why is it negative?
by Glenda Marshall DIS 3M
Fri Jan 16, 2015 1:25 pm
Forum: Phase Changes & Related Calculations
Topic: Homework Problem #19
Replies: 5
Views: 774

Homework Problem #19

In this problem it says that a piece of copper at 100 degrees celsius is put into water at 22 degrees celsius. I am confused why the copper has a positive "q" value while the water has a negative "q" value. If the water is absorbing heat given off by the copper shouldn't it be th...
by Glenda Marshall DIS 3M
Fri Jan 09, 2015 11:43 pm
Forum: Phase Changes & Related Calculations
Topic: State/Path Functions
Replies: 3
Views: 3563

Re: State/Path Functions

When something is path dependent, it means that the method used to reach the final product affects the answer. For example, Dr. Lavelle use the example of two groups climbing a mountain. If one group goes straight up one side, they will exert less energy because they are just powering through and ta...
by Glenda Marshall DIS 3M
Fri Dec 12, 2014 10:12 pm
Forum: *Titrations & Titration Calculations
Topic: Using Henderson Hasselbalch Equation on the Final
Replies: 2
Views: 402

Using Henderson Hasselbalch Equation on the Final

I 've been told in many review sessions that it is okay to use the Henderson Hasselbalch Equation in a titration when the reaction is in the buffer region. For example: Suppose that 25mL of .10M CH3COOH is titrated with .10M NaOH. What is the pH after the addition of 10mL of .10M NaOH? After finding...
by Glenda Marshall DIS 3M
Thu Dec 11, 2014 10:52 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Homework 12.21
Replies: 3
Views: 463

Homework 12.21

In problem 12.21, I understand that the ratio of CO3 and HCO3 is related by the HH equation. However, in the answer it uses a pKa2 value. I know this value is necessary to solve the problem, so I am curious how I find it without numerical values given in the problem.
by Glenda Marshall DIS 3M
Thu Dec 11, 2014 5:26 pm
Forum: *Making Buffers & Calculating Buffer pH (Henderson-Hasselbalch Equation)
Topic: Calculating pH and pH change in a buffer solution (12.11)
Replies: 4
Views: 1225

Re: Calculating pH and pH change in a buffer solution (12.11

Caitlin- The idea of a buffer is that whether you add an acid or a base, the pH will not change and therefore neither H30+ or OH- will be created. The reason you subtract is because, as the NaOH is added, the CH3COOH will give up it's hydrogen to neutralize the OH- in the NaOH. This the concentratio...
by Glenda Marshall DIS 3M
Wed Dec 10, 2014 10:24 pm
Forum: *Titrations & Titration Calculations
Topic: Calculating the acidity of a salt
Replies: 1
Views: 257

Calculating the acidity of a salt

In class today, we discussed that when an weak acid and base react, it will yield a salt and water. The conjugate base, however, reacted again with the water to form it's conjugate acid and hydroxide. When solving for the hydroxide concentration, we used the moles of the initial acid to calculate th...
by Glenda Marshall DIS 3M
Wed Dec 10, 2014 9:17 pm
Forum: Bronsted Acids & Bases
Topic: HCOOH vs. CH3COOH
Replies: 1
Views: 504

HCOOH vs. CH3COOH

Why is CH3COOH weaker than HCOOH even though it has an extra carbon to help delocalize the charge?
by Glenda Marshall DIS 3M
Tue Dec 09, 2014 5:27 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Homework Question 11.35
Replies: 1
Views: 284

Homework Question 11.35

I am confused by part B of this homework problem. If the initial solution is 200 mL of NaOH, why do I only use M1V1=M2V2 once? Shouldn't I use it again with 200mL as V2?
by Glenda Marshall DIS 3M
Fri Dec 05, 2014 12:27 am
Forum: Ideal Gases
Topic: Homework 10.69
Replies: 3
Views: 464

Re: Homework 10.69

Thank you so much!
by Glenda Marshall DIS 3M
Wed Dec 03, 2014 9:05 pm
Forum: Ideal Gases
Topic: Homework 10.69
Replies: 3
Views: 464

Homework 10.69

I am still super confused on how to do problem 69. Can someone please explain how you can get the volume when you don't know the pressure?
by Glenda Marshall DIS 3M
Sun Nov 30, 2014 11:28 pm
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: K value for changes in temperature
Replies: 2
Views: 451

K value for changes in temperature

I'm still confused why K changes when temperature changes. Anyone care to explain?
by Glenda Marshall DIS 3M
Tue Nov 11, 2014 3:31 pm
Forum: Dipole Moments
Topic: Polarity of Charged Molecules
Replies: 1
Views: 323

Polarity of Charged Molecules

If a molecule has an overall charge, does that automatically make it polar? For example, NH4+?
by Glenda Marshall DIS 3M
Thu Nov 06, 2014 1:58 pm
Forum: Dipole Moments
Topic: Ch.3 #19
Replies: 1
Views: 348

Ch.3 #19

I am confused about the dipole moments in question 19. Obviously, Fluorine is more electronegative than Sulfur, but how does the lone pair effect the partial charges. Does it make the sulfur more electronegative than Fluorine? And why is the molecule polar?
by Glenda Marshall DIS 3M
Thu Nov 06, 2014 1:54 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angular vs. Bent
Replies: 7
Views: 1154

Angular vs. Bent

I've noticed that the terms "angular" and "bent" seemed to be used synonymously. Is there a difference between the two?
by Glenda Marshall DIS 3M
Thu Nov 06, 2014 1:53 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angular vs. Bent
Replies: 1
Views: 270

Angular vs. Bent

I've noticed that the terms "angular" and "bent" seemed to be used synonymously. Is there a difference between the two?
by Glenda Marshall DIS 3M
Wed Nov 05, 2014 9:30 pm
Forum: Bond Lengths & Energies
Topic: Chapter 2 Question 101
Replies: 1
Views: 371

Chapter 2 Question 101

In Chapter 2 problem #101, why is Zinc considered excited?
by Glenda Marshall DIS 3M
Tue Nov 04, 2014 5:25 pm
Forum: Bond Lengths & Energies
Topic: How to tell whether an atom is excited?
Replies: 1
Views: 342

How to tell whether an atom is excited?

In question #101 in chapter 2, it gives you a chart that you must fill out. One of the columns requests to know whether the atom is excited or in a ground state. How would you get this information from what is given?
by Glenda Marshall DIS 3M
Thu Oct 30, 2014 12:48 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Bonds and Energy
Replies: 1
Views: 259

Bonds and Energy

What does it mean for a certain lewis structure to have a "greater contribution" to a resonance hybrid. I know that each possible less structure contributes to the real structure, but how can one contribute more?
by Glenda Marshall DIS 3M
Fri Oct 24, 2014 11:50 pm
Forum: Lewis Structures
Topic: Exceptions to Octet Rule
Replies: 1
Views: 320

Exceptions to Octet Rule

Why is phosphorus the first element that can accommodate more than 8 electrons when silicon and aluminum also have a d level?
by Glenda Marshall DIS 3M
Fri Oct 17, 2014 4:31 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Energy Levels
Replies: 1
Views: 412

Energy Levels

If we picture an s-orbital as a sphere and an electron can reside anywhere inside the volume of that sphere, then why does the electron only get excited by certain wavelengths of light? I thought electrons couldn't be below or above their levels.
by Glenda Marshall DIS 3M
Sat Oct 11, 2014 8:09 pm
Forum: Molarity, Solutions, Dilutions
Topic: Solving for volume when given density?
Replies: 3
Views: 463

Solving for volume when given density?

There is a problem on the homework that gives density and percent composition of a compound and then molarity and volume of the final solution. How does the density relate to the information given and how can I use it to solve the problem?

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