Search found 50 matches

by Michaela Capps 1l
Sun Mar 18, 2018 2:13 pm
Forum: *Carboxylic Acids
Topic: Functional Groups
Replies: 4
Views: 464

Re: Functional Groups

My TA said we will probably have to identify them in complex molecules but not have to draw them individually.
by Michaela Capps 1l
Sun Mar 18, 2018 2:12 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Homework 14.15c : KOH in cell diagram
Replies: 2
Views: 189

Re: Homework 14.15c : KOH in cell diagram

Yes you can use just OH because K is not involved in the redox reactions.
by Michaela Capps 1l
Sun Mar 18, 2018 2:10 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Adiabatic System
Replies: 5
Views: 389

Re: Adiabatic System

Doesn't necessarily mean it is always reversible, but it will always be transferred as work because q=0.
by Michaela Capps 1l
Sun Mar 18, 2018 2:08 pm
Forum: General Rate Laws
Topic: The Collision Model and Activated Complex Model
Replies: 3
Views: 374

Re: The Collision Model and Activated Complex Model

Collision theory has to collide at same time, same orientation and enough energy to overcome the activation energy.
by Michaela Capps 1l
Sun Mar 18, 2018 2:07 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Phase changes and entropy
Replies: 5
Views: 313

Re: Phase changes and entropy

Delta H is equal to q at a constant pressure.
by Michaela Capps 1l
Sun Mar 18, 2018 2:03 pm
Forum: *Identifying Primary, Secondary, Tertiary, Quaternary Carbons, Hydrogens, Nitrogens
Topic: Final
Replies: 3
Views: 449

Re: Final

I would assume both just complex because you'd have to understand what the functional groups are
by Michaela Capps 1l
Sun Mar 18, 2018 2:01 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Putting an Ice cube into a glass of water
Replies: 4
Views: 659

Re: Putting an Ice cube into a glass of water

You're right--you do need delta H of fusion because heat is lost from ice to water.
by Michaela Capps 1l
Sun Mar 18, 2018 1:58 pm
Forum: Second Order Reactions
Topic: Derivations
Replies: 4
Views: 464

Re: Derivations

It is postitive because y=mx+b so the slope is positive.
by Michaela Capps 1l
Sun Mar 18, 2018 1:58 pm
Forum: Second Order Reactions
Topic: Derivations
Replies: 4
Views: 464

Re: Derivations

For the first question, in the integrated rate law, kt is positive, so that is why we use pos slope.
by Michaela Capps 1l
Sun Mar 18, 2018 1:49 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Kinetically controlled reactions
Replies: 2
Views: 193

Re: Kinetically controlled reactions

Yes Alexander is right. Even though a reaction might be thermodynamically favorable, it still has to overcome an activation energy.
by Michaela Capps 1l
Sun Mar 18, 2018 1:46 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Cp and Cv
Replies: 5
Views: 254

Re: Cp and Cv

Cp and Cv are usually just used for different conditions, either constant pressure or constant volume. I'm not sure when u would switch.
by Michaela Capps 1l
Sun Mar 18, 2018 1:44 pm
Forum: Reaction Mechanisms, Reaction Profiles
Topic: steady state vs pre equilibrium
Replies: 3
Views: 240

Re: steady state vs pre equilibrium

Pre equilibrium is easy to use but is not as flexible at steady state approximations which is usually used for complex mechanisms.
by Michaela Capps 1l
Sun Mar 18, 2018 1:42 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Maximum Work
Replies: 3
Views: 256

Re: Maximum Work

It is a part of the laws of thermodynamics.
by Michaela Capps 1l
Sun Mar 18, 2018 1:40 pm
Forum: Phase Changes & Related Calculations
Topic: carbon
Replies: 4
Views: 273

Re: carbon

You have to sublimize Carbon to the gaseous state because deltaH has to have them all as gasses.
by Michaela Capps 1l
Fri Mar 16, 2018 10:08 pm
Forum: *Nucleophiles
Topic: nucleophile?
Replies: 4
Views: 293

Re: nucleophile?

The molecule that is substituting the leaving group.
by Michaela Capps 1l
Fri Mar 16, 2018 10:08 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.109
Replies: 2
Views: 135

Re: 15.109

In order to subtract the 1/T and 1/T' you have to have a common denominator. so you multiply both by the others denominator.
by Michaela Capps 1l
Fri Mar 16, 2018 9:48 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: 14.91
Replies: 1
Views: 92

Re: 14.91

The anode is more negative so it makes sense that it is receiving negative electrolytes.
by Michaela Capps 1l
Fri Mar 16, 2018 9:44 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: 8.99
Replies: 1
Views: 175

Re: 8.99

This is the idea that in a perfect system q(metal)+q(water)=0 so making overall q(water) negative, will be equal to q(metal).
by Michaela Capps 1l
Fri Mar 16, 2018 9:33 pm
Forum: Concepts & Calculations Using First Law of Thermodynamics
Topic: 8.51b
Replies: 1
Views: 151

Re: 8.51b

Yes it is because it is already in kJ/mol
by Michaela Capps 1l
Fri Mar 16, 2018 9:21 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Work and derivations
Replies: 2
Views: 236

Re: Work and derivations

For calculating delta n (change in moles) we look at gas phase molecules in the chem equation because those are the only ones that will affect work done. In this problem, were given 6mol H20 and 6 mol CO2 in gas phase on products, totaling 12 moles, and 6 mol O2 on gas phase on the reactants (we ign...
by Michaela Capps 1l
Fri Mar 16, 2018 9:17 pm
Forum: Balancing Redox Reactions
Topic: determining cathode from anode
Replies: 11
Views: 406

Re: determining cathode from anode

You would look at the standard cell potentials. The most positive is the cathode. Also, cathode-(anode) should be positive.
by Michaela Capps 1l
Fri Mar 16, 2018 9:13 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: Degeneracy
Replies: 1
Views: 170

Re: Degeneracy

Number of orientations raised to the number of molecules. This tells you all of the possible orientations the molecules can have.
by Michaela Capps 1l
Fri Mar 16, 2018 9:11 pm
Forum: Arrhenius Equation, Activation Energies, Catalysts
Topic: 15.61
Replies: 2
Views: 104

Re: 15.61

We didn't go over this derivation and also are not responsible for knowing it.
by Michaela Capps 1l
Fri Mar 16, 2018 9:10 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: delta S for reversible and irreversible reactions
Replies: 1
Views: 147

Re: delta S for reversible and irreversible reactions

When it is reversible, the system is at equilibrium so it =0. When deltaS >0 the reaction is spontaneous, which is a part of the second law of thermodynamics
by Michaela Capps 1l
Fri Mar 16, 2018 9:07 pm
Forum: Interesting Applications: Rechargeable Batteries (Cell Phones, Notebooks, Cars), Fuel Cells (Space Shuttle), Photovoltaic Cells (Solar Panels), Electrolysis, Rust
Topic: 14.119
Replies: 2
Views: 204

Re: 14.119

The half reactions only include the elements that are being oxidized or reduced. The net ionic equation will include all elements (and spectator ions) to balance the two sides.
by Michaela Capps 1l
Fri Mar 16, 2018 9:03 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: S and delta S
Replies: 4
Views: 256

Re: S and delta S

S is the residual entropy while delta S is the change in entropy.
by Michaela Capps 1l
Fri Mar 16, 2018 9:02 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: electrode surface area and voltage
Replies: 1
Views: 115

Re: electrode surface area and voltage

Cell potential only depends on concentration so electrode surface area doesn't affect it.
by Michaela Capps 1l
Sun Jan 14, 2018 5:26 pm
Forum: Phase Changes & Related Calculations
Topic: 8.41
Replies: 4
Views: 195

Re: 8.41

You have to solve by melting the ice, and then by bringing the liquid to the final temperature (which is endothermic/requiring heat). Heat absorbed by ice cube = (50g/18.02g*mol )(6.01*10^3 J*mol^-1) + 50g*4.184J*C^-1 *g^-1 * (Final Temperature-0 degrees C) Heat released by liquid water = (400g)(4.1...
by Michaela Capps 1l
Sun Jan 14, 2018 5:15 pm
Forum: Phase Changes & Related Calculations
Topic: 8.45 part C
Replies: 2
Views: 121

Re: 8.45 part C

I used a ratio so I set up 358.8kj/4 molCS2 = 415kj/x moles and then I solved for x.
by Michaela Capps 1l
Sun Dec 10, 2017 12:45 am
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Percent Ionization Formula
Replies: 1
Views: 299

Re: Percent Ionization Formula

The amount ionized(starting-ending)/starting amount *100 would be the percentage
by Michaela Capps 1l
Sun Dec 10, 2017 12:39 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Effect of water
Replies: 2
Views: 239

Re: Effect of water

It depends on if the reactants or products are aqueous. If they were, adding water would change the molarity and thus the reaction and how it proceeds.
by Michaela Capps 1l
Sun Dec 10, 2017 12:38 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Test 4 #6
Replies: 2
Views: 268

Re: Test 4 #6

For my test 4 #6, There were only 3 values? A + B <---> 2C. If you are asking about the 2 on the 2C, it would come into play for the change line of the ICE table (and be 2x instead of x).
by Michaela Capps 1l
Sun Dec 10, 2017 12:36 am
Forum: Applying Le Chatelier's Principle to Changes in Chemical & Physical Conditions
Topic: Adding Water
Replies: 2
Views: 240

Re: Adding Water

^^^ Yes I also believe this to be right. The equation would specify by including the physical properties of the reactants and products in the equation. If any were aqueous then you would know to watch out for that
by Michaela Capps 1l
Sun Dec 10, 2017 12:34 am
Forum: Non-Equilibrium Conditions & The Reaction Quotient
Topic: Compression effect on a system
Replies: 2
Views: 222

Re: Compression effect on a system

Just to expand, the equation will shift towards the side with less moles of gas in an attempt to reduce the pressure and return to equilibrium
by Michaela Capps 1l
Sun Dec 10, 2017 12:33 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Significant figures in calculations
Replies: 1
Views: 184

Re: Significant figures in calculations

Yes it would be the same number of SF as the K value
by Michaela Capps 1l
Sun Dec 10, 2017 12:32 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Changing Stoichiometric Coefficients
Replies: 2
Views: 328

Re: Changing Stoichiometric Coefficients

The coefficients are superscripts for equilibrium expressions so when it said half coefficients, I put the half in the superscript of the x. If it said double all coefficients, you would have x^2
by Michaela Capps 1l
Wed Nov 15, 2017 1:13 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Bond Order
Replies: 5
Views: 302

Re: Bond Order

The .5 in bond order indicates resonance. 1.5 bond order is going to be the average of single and double bonds in a resonance hybrid
by Michaela Capps 1l
Wed Nov 15, 2017 1:09 pm
Forum: Bond Lengths & Energies
Topic: Factors that control bond length
Replies: 3
Views: 568

Re: Factors that control bond length

For covalent, the difference in electro negativity will determine if the bond is either polar or non polar. And yes the increasing number of bonds decreases the bond length. Higher bond order (number of bonds) indicated more attraction between electrons and the atoms will be held closer together
by Michaela Capps 1l
Wed Nov 15, 2017 1:04 pm
Forum: Electronegativity
Topic: Isoelectronic [ENDORSED]
Replies: 11
Views: 509

Re: Isoelectronic [ENDORSED]

Also means they have the same electronic structure and will have similar chemical properties
by Michaela Capps 1l
Wed Nov 15, 2017 1:02 pm
Forum: Octet Exceptions
Topic: Why do octets expand?
Replies: 4
Views: 276

Why do octets expand?

I have memorized that there can be octet expansions for elements in the 3rd period and beyond but I don't think I really understand why that is? I usually remember things better when I understand everything versus just memorizing so can someone please explain? Thanks!
by Michaela Capps 1l
Wed Nov 15, 2017 12:57 pm
Forum: Hybridization
Topic: Hybridization beyond d orb
Replies: 1
Views: 105

Hybridization beyond d orb

We have mostly just looked at the hybridizations of elements with a maximum of d orbitals, but what would the hybridization for an atom with say an f orbital look like?
by Michaela Capps 1l
Wed Nov 15, 2017 12:53 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Configuration of Gallium
Replies: 3
Views: 567

Re: Electron Configuration of Gallium

Yes, even though you fill the 4s before the 3d orbital, you should write it in order of ascending energy, which would be 3d then 4s. This also makes it easier to see what electrons will be ionized (from the highest energy orbital)
by Michaela Capps 1l
Wed Nov 15, 2017 12:50 pm
Forum: Lewis Structures
Topic: Expanded Valence Shell
Replies: 2
Views: 148

Re: Expanded Valence Shell

I believe that in general, not more that 16 electrons will be involved
by Michaela Capps 1l
Wed Nov 15, 2017 12:46 pm
Forum: Sigma & Pi Bonds
Topic: # of sigma and pi bonds [ENDORSED]
Replies: 4
Views: 268

Re: # of sigma and pi bonds [ENDORSED]

And in each double/triple bond, the first bond will be a sigma bond, and then the successive bond(s) will be pi bonds
by Michaela Capps 1l
Sun Oct 29, 2017 8:27 pm
Forum: Properties of Electrons
Topic: Ending Frequency [ENDORSED]
Replies: 3
Views: 300

Re: Ending Frequency [ENDORSED]

If you are talking about the Bohr frequency model (just because it includes E and results in frequency) then you are going to use the delta E/change in energy
by Michaela Capps 1l
Sun Oct 29, 2017 8:24 pm
Forum: Properties of Electrons
Topic: Energy level question [ENDORSED]
Replies: 2
Views: 233

Energy level question [ENDORSED]

Why is it that n=1 is the lowest energy level?
by Michaela Capps 1l
Tue Oct 10, 2017 1:03 pm
Forum: Properties of Light
Topic: chapter 1 question 27
Replies: 2
Views: 135

Re: chapter 1 question 27

Okay so you were right to want to use E=h·ν but you rearrange it because v ("nu" or frequency)=c/λ so we can use E=hc/λ =(6.626·10^-34 Js)·( 2.997·10^8m/s)/ (470·10-9 m)=4.225*10^-19 J. The lamp emits 32J/s so in 2 seconds, the lamp emits (32*2=) 64J. So we use E(per mol of photons)=N(phot...
by Michaela Capps 1l
Tue Oct 10, 2017 12:43 pm
Forum: Properties of Light
Topic: Photoelectric Effect Post-Module Assessment (28B) [ENDORSED]
Replies: 1
Views: 155

Re: Photoelectric Effect Post-Module Assessment (28B) [ENDORSED]

The work function is given to us in kJ/mol but we want it per electron so we use Avogadro's constant. First I converted kJ to J by multiplying my 10^3 because that's what's easiest for me in terms of conversions. (150*10^3 J/mol) x (1 mol/6.02*10^23)...moles cancel out so we are left with 2.50*10^-1...
by Michaela Capps 1l
Tue Oct 03, 2017 6:23 pm
Forum: Significant Figures
Topic: Sig Figs in 0.0380 [ENDORSED]
Replies: 5
Views: 360

Sig Figs in 0.0380 [ENDORSED]

In class, Lavelle said there were 3 sig figs and I was just confused on which zero was included in the 3 SF? Thanks!

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