Search found 24 matches

by Navarro_Bree_1D
Thu Mar 16, 2017 12:30 pm
Forum: Administrative Questions and Class Announcements
Topic: Saying Thank You to Dr. Lavelle
Replies: 209
Views: 97951

Re: Saying Thank You to Dr. Lavelle

Dear Dr. Lavelle, Thank you for your dedication and passion towards this course and your students. I've had the highest pleasure of being in your class for 14A and 14B. You are one of the best professors I've ever had at UCLA. You provide us with more than enough resources to succeed. You will be de...
by Navarro_Bree_1D
Tue Mar 07, 2017 10:24 am
Forum: *Organic Reaction Mechanisms in General
Topic: Question 4.37
Replies: 2
Views: 294

Re: Question 4.37

The standard enthalpy of activation will always be positive because bonds are being distorted and extended. Activation energy = Standard enthalpy of activation + RT. As we can see from the equation above, the barrier to the transition state is an enthalpic one, that is why the standard enthalpy of a...
by Navarro_Bree_1D
Tue Mar 07, 2017 10:10 am
Forum: *Nucleophiles
Topic: Thiocyanate Lewis Structure [ENDORSED]
Replies: 3
Views: 997

Re: Thiocyanate Lewis Structure [ENDORSED]

The central N atom has 4 electrons than its usual 5. That's why there is a positive charge on it
by Navarro_Bree_1D
Tue Mar 07, 2017 9:07 am
Forum: *Alkanes
Topic: Naming [ENDORSED]
Replies: 92
Views: 8253

Re: Naming [ENDORSED]

Pentyl is the IUPAC naming and amyl is the common naming
by Navarro_Bree_1D
Tue Mar 07, 2017 9:04 am
Forum: *Organic Reaction Mechanisms in General
Topic: Naming Organic Molecules
Replies: 19
Views: 1989

Re: Naming Organic Molecules

To answer your question, Caleb, you treat halogens the same way you treat substituents on an alkane chain/ring. The halogen has equal rank as any other substituent.

Ex//: CH3CHClCH2CH3 --> 2-chlorobutane

(More examples on page 93 of the Course Reader)
by Navarro_Bree_1D
Mon Feb 27, 2017 10:45 pm
Forum: *Free Energy of Activation vs Activation Energy
Topic: Free energy of activation vs. activation energy
Replies: 2
Views: 852

Re: Free energy of activation vs. activation energy

I would like to add that free energy of activation and activation energy have very similar values, but they are not exactly equal. Free energy of activation is more accurate than activation energy because free energy of activation includes both the standard enthalpy of activation and the standard en...
by Navarro_Bree_1D
Tue Feb 21, 2017 11:11 am
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Homework 15.79
Replies: 4
Views: 402

Re: Homework 15.79

Here is a youtube video that goes over the difference between thermodynamic and kinetic control.

https://www.youtube.com/watch?v=l-l_8cSQdEw
by Navarro_Bree_1D
Thu Feb 16, 2017 3:00 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Thermodynamics
Replies: 2
Views: 284

Re: Thermodynamics

Residual and positional entropy are the same thing. I would like to add that molar residual entropy is different than residual/positional entropy. When determining the degeneracy of molar residual entropy, the exponent used in Avogadro's constant. This makes sense because molar residual entropy repr...
by Navarro_Bree_1D
Tue Feb 07, 2017 11:10 pm
Forum: Balancing Redox Reactions
Topic: Question 7 2013 Midterm
Replies: 1
Views: 190

Re: Question 7 2013 Midterm

The value of n is determined by the number of electrons needed to balance the two half reactions. For the half reaction with Mn2+, there are 5 electrons. For the half reaction with Br2, there are 2 electron. In order to balance the overall equation, you need to multiply the half reaction with Mn2+ b...
by Navarro_Bree_1D
Wed Feb 01, 2017 5:56 pm
Forum: Phase Changes & Related Calculations
Topic: Entropy vs Enthalpy
Replies: 2
Views: 389

Re: Entropy vs Enthalpy

It is important to know that enthalpy (delta H) is the amount of heat released/absorbed at constant pressure. Without constant pressure, it is just heat, not enthalpy.
by Navarro_Bree_1D
Wed Jan 25, 2017 1:14 pm
Forum: Gibbs Free Energy Concepts and Calculations
Topic: Gas Phase Only vs Liquid Phase Only
Replies: 1
Views: 241

Re: Gas Phase Only vs Liquid Phase Only

From the reaction: Br2(l) --> Br2(g), you know you are starting with a liquid and ending with a gas. When T>333K, the temp is high enough to make the reaction spontaneous. Therefore the reaction is considered "gas phase only" because all of the liquid Br2 is becoming gaseous Br2. When T<33...
by Navarro_Bree_1D
Thu Jan 19, 2017 7:55 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Chapter 8.49
Replies: 1
Views: 256

Chapter 8.49

You are given the following: OF2(g) + H2O(g) --> O2(g) + 2HF(g) Delta H = -318 kJ What is the change in internal energy for the reaction of 1.00 mol OF2? We need to use PV=nRT but there is no T given and this delta H is not the standard reaction enthalpy. Yet the solution uses 25 degrees Celsius. Ho...
by Navarro_Bree_1D
Sat Jan 14, 2017 10:48 am
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Calculating Heat Required
Replies: 3
Views: 448

Re: Calculating Heat Required

Although these heat equations look very similar, they are quite different. 1. Qp=n*Cp*change in temperature 2. Q=(mass)*Csp*change in temperature For the first equation, -heat is at constant pressure -n = # of moles -Cp = molar heat capacity at constant pressure (kJ/C mol) -you use moles to cancel o...
by Navarro_Bree_1D
Tue Nov 29, 2016 7:40 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Homework Help 12.65
Replies: 4
Views: 642

Re: Homework Help 12.65

I also had a question about this too. For part e and part f, why do you attach 6 molecules of water to the transition metal?
by Navarro_Bree_1D
Tue Nov 29, 2016 12:46 pm
Forum: Conjugate Acids & Bases
Topic: Naming conjugate acids
Replies: 1
Views: 310

Re: Naming conjugate acids

Which homework question are you referring to specifically?

I am pretty sure you just add H^+ to the end of the compound. So it would be NH2NH3^+
by Navarro_Bree_1D
Tue Nov 22, 2016 10:02 pm
Forum: Properties & Structures of Inorganic & Organic Acids
Topic: Strong Acid or Weak Acid
Replies: 3
Views: 547

Re: Strong Acid or Weak Acid

Here is a general rule of thumb when determining the relative strength of acids: 1. Is the acid organic or inorganic? --Organic acids (compounds with carbon) are usually weaker than inorganic acids (compounds WITHOUT carbon) **NOTE: Acids can be modified to be stronger** 2. What elements make up the...
by Navarro_Bree_1D
Wed Nov 16, 2016 10:03 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: Equilibrium Shifts
Replies: 1
Views: 245

Re: Equilibrium Shifts

The answers for your question can be found in the course reader, on page 139. (-: If a reaction is exothermic while forming products, then heating will favor the formation of reactants. (shift to the left) If a reaction is endothermic while forming products, then heating will favor the formation of ...
by Navarro_Bree_1D
Wed Nov 09, 2016 10:26 am
Forum: Naming
Topic: cis/trans naming
Replies: 2
Views: 291

Re: cis/trans naming

For the quiz, my TA said we need to know how to name cis and trans from a diagram or draw a structure from the name given (cis or trans). I don't think we will have to know if the compound is cis or trans when the only information given is the elements. If you want to make sure, I would go to Profes...
by Navarro_Bree_1D
Fri Nov 04, 2016 9:30 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Fall 2012 Midterm Q5B
Replies: 2
Views: 408

Re: Fall 2012 Midterm Q5B

This problem wants to know which gases contribute to global warming. Gases with dipole moments contribute to global warming. These dipole moments do not have to occur in the most stable form of the gas. The Lewis structure of SO2 with a single bond and double bond is a better representation for this...
by Navarro_Bree_1D
Wed Oct 26, 2016 10:17 am
Forum: Ionic & Covalent Bonds
Topic: Chapter 3 Homework #13
Replies: 2
Views: 597

Re: Chapter 3 Homework #13

In addition, you must remove an electron from the orbital with the highest energy level because these electrons are the easiest to remove compared to the electrons from orbitals with lower energy levels. The electron configuration of Cl is [Ne]3s^2 3p^5. --The highest energy level is 3p. --Therefore...
by Navarro_Bree_1D
Wed Oct 19, 2016 5:15 pm
Forum: Lewis Structures
Topic: Lewis Structure Problem 3.39 [ENDORSED]
Replies: 1
Views: 266

Lewis Structure Problem 3.39 [ENDORSED]

3.39 Write the complete Lewis structure for each of the following compounds: (a) ammonium chloride (b) potassium phosphide (c) sodium hypochlorite I am confused on how to draw Lewis Structures for ionic compounds that also have covalent bonds. In the solutions manual, they put brackets around NH4, P...
by Navarro_Bree_1D
Thu Oct 13, 2016 6:00 pm
Forum: *Particle in a Box
Topic: Why can't a particle in a container have zero energy?
Replies: 2
Views: 920

Re: Why can't a particle in a container have zero energy?

According to the website, "Fermilab Today," at the quantum scale, space never has zero energy because electrons have both particle-like and wave-like properties. Their constant movement can be measured in kinetic energy. From my understanding, I think a particle in a container cannot have ...
by Navarro_Bree_1D
Tue Oct 04, 2016 11:10 pm
Forum: Properties of Light
Topic: Textbook Example 1.5 Analyzing the Photoelectric Effect [ENDORSED]
Replies: 1
Views: 346

Textbook Example 1.5 Analyzing the Photoelectric Effect [ENDORSED]

Example: The speed of an electron emitted from the surface of a sample of Potassium by a photon is 668km/s. Its work function is 2.29 eV. - What is the wavelength of the radiation that caused photo-ejection of the electron? In the textbook, they convert the work function from electron-volts to joule...
by Navarro_Bree_1D
Thu Sep 29, 2016 4:55 pm
Forum: Properties of Light
Topic: Kinetic Energy
Replies: 4
Views: 706

Re: Kinetic Energy

I think the equation does not include rotational energy because rotational energy at the atomic level is not significant enough to take into account. The moment of inertia is extremely small.

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