Search found 24 matches

by Shelby Slaughter 3D
Mon Mar 13, 2017 5:41 pm
Forum: Administrative Questions and Class Announcements
Topic: Formula Sheet for the Final Exam
Replies: 5
Views: 718

Re: Formula Sheet for the Final Exam

I would assume its identical to the formula sheet in the course reader before the practice exams, see page 125
by Shelby Slaughter 3D
Mon Mar 13, 2017 3:17 pm
Forum: *Cyclopropanes and Cyclobutanes
Topic: Rotation of cycloalkanes
Replies: 2
Views: 744

Re: Rotation of cycloalkanes

The Carbon atoms in cyclobutane, unlike cyclopropane, can rotate to stagger the hydrogen atoms and relieve torsional strain. Cyclopropane must be planar, and cyclobutane takes a butterfly confirmation because it is more stable this way than as planar.
by Shelby Slaughter 3D
Mon Mar 06, 2017 3:48 pm
Forum: *Identifying Primary, Secondary, Tertiary, Quaternary Carbons, Hydrogens, Nitrogens
Topic: Naming organic molecules
Replies: 1
Views: 705

Re: Naming organic molecules

its the number of the carbon in the parent chain that the chlorine of butanol is attached to
by Shelby Slaughter 3D
Mon Feb 27, 2017 5:45 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Naming Organic Molecules
Replies: 19
Views: 2544

Re: Naming Organic Molecules

The Introduction to Organic Chemistry text keeps referring to carbocations in Chapter 4. What exactly are these?
by Shelby Slaughter 3D
Mon Feb 20, 2017 9:30 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz 2 Winter 2017
Replies: 160
Views: 17140

Re: Quiz 2 Winter 2017

Will we need to know the details of radioactive decay?
by Shelby Slaughter 3D
Mon Feb 13, 2017 2:49 pm
Forum: Work, Gibbs Free Energy, Cell (Redox) Potentials
Topic: Concentration Cells
Replies: 2
Views: 378

Re: Concentration Cells

Standard reduction potentials measure the potential difference between two electrodes. If the electrodes are made of the same material there is no difference. The different concentrations of the solutions only affect E cell, not standard E cell. See the diagram on page 53 in the course reader.
by Shelby Slaughter 3D
Mon Feb 13, 2017 2:41 pm
Forum: Balancing Redox Reactions
Topic: winter 2014 midterm #8
Replies: 1
Views: 281

Re: winter 2014 midterm #8

To calculate K the concentration of products must be over concentration reactants. For Ka calculations the H+ concentration value must be on top, so in order to get an total equation producing H+ the equation containing HF must be the anode, even though standard Ecell is negative and therefore not f...
by Shelby Slaughter 3D
Mon Feb 06, 2017 5:09 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Enthalpy
Replies: 4
Views: 564

Re: Enthalpy

For 14.9a Ce goes from having a charge of +8 to +6, therefore n=2 (be careful to notice stoichiometric coefficients!)
by Shelby Slaughter 3D
Mon Jan 30, 2017 2:14 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: Residual Entropy 3rd Law of Thermodynamics
Replies: 4
Views: 680

Re: Residual Entropy 3rd Law of Thermodynamics

But if 0K was reached would the residual entropy theoretically be zero, or still just infinitely small?
by Shelby Slaughter 3D
Mon Jan 23, 2017 11:50 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: chapter 9 question 23
Replies: 2
Views: 337

chapter 9 question 23

What does the answer of this question mean when it says that "it would be possible for the molecule to be disordered"?
by Shelby Slaughter 3D
Mon Jan 16, 2017 10:59 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hc and Hf
Replies: 3
Views: 644

Re: Hc and Hf

I believe that Hc is the standard enthalpy of combustion, or the enthalpy change per mole of something burned during combustion. So, I would say it is used for combustion reactions. However, I am unsure if reactants and products must be in standard state. The text book only say "under standard ...
by Shelby Slaughter 3D
Mon Jan 16, 2017 4:08 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Hc and Hf
Replies: 3
Views: 644

Re: Hc and Hf

Hf is for standard enthalpy of formation which is the standard reaction enthalpy for forming one mole of a substance from its elements, but only when its elements are in their most stable form. Where have you seen Hc??
by Shelby Slaughter 3D
Wed Jan 11, 2017 8:26 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Units for Standard Enthalpy of Reaction
Replies: 1
Views: 306

Re: Units for Standard Enthalpy of Reaction

Yes you are correct, they are both kj/mole as it states in our course reader.
by Shelby Slaughter 3D
Mon Nov 28, 2016 4:52 pm
Forum: Calculating pH or pOH for Strong & Weak Acids & Bases
Topic: Chapter 12 Question 69b
Replies: 2
Views: 450

Re: Chapter 12 Question 69b

The same reaction is used in question 12.65, I was wondering why it is (h20)6? Why not 5 or 4 or even 3?
by Shelby Slaughter 3D
Mon Nov 21, 2016 1:43 pm
Forum: Conjugate Acids & Bases
Topic: pH and pOH
Replies: 4
Views: 815

Re: pH and pOH

I've heard that it stands for potential, but other sources say it was just chosen at random. Here is a short article about it.http://cultureofchemistry.fieldofscienc ... ds-ph.html
by Shelby Slaughter 3D
Wed Nov 16, 2016 7:15 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Question on 17.31
Replies: 1
Views: 337

Re: Question on 17.31

Ligands are supposed to be arranged alphabetically so aqua comes before oxalato!
by Shelby Slaughter 3D
Wed Nov 09, 2016 1:10 pm
Forum: Naming
Topic: Naming Compounds
Replies: 2
Views: 366

Re: Naming Compounds

Unless questions in the homework and the practice quizzes require this knowledge, which I do not believe they do, we do not have to worry about it!
by Shelby Slaughter 3D
Mon Oct 31, 2016 4:04 pm
Forum: Lewis Structures
Topic: Oxidation Number of Thallium in Tl2O3
Replies: 3
Views: 823

Re: Oxidation Number of Thallium in Tl2O3

The oxidation state of Oxygen is -2 , and since there are three oxygen the overall charge of oxygen in this molecule is -6. Because there are two thallium atoms their charges must each be +3 each to balance the oxidation states.
by Shelby Slaughter 3D
Wed Oct 26, 2016 3:07 pm
Forum: Administrative Questions and Class Announcements
Topic: Quiz Grades
Replies: 3
Views: 628

Re: Quiz Grades

I was wondering if we are able to check quiz grades online? I can't find a CCLE link and the grades section on myUCLA is blank.
by Shelby Slaughter 3D
Tue Oct 18, 2016 11:24 am
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 8039
Views: 1410369

Re: Post All Chemistry Jokes Here

I heard they're starting a whole new chem channel devoted to as xenon tv products.
by Shelby Slaughter 3D
Tue Oct 11, 2016 3:24 pm
Forum: Administrative Questions and Class Announcements
Topic: Quizes
Replies: 21
Views: 1790

Re: Quizes

Are pencils or pens preferred on quizzes?
by Shelby Slaughter 3D
Fri Oct 07, 2016 12:41 pm
Forum: Heisenberg Indeterminacy (Uncertainty) Equation
Topic: Changing signs [ENDORSED]
Replies: 2
Views: 410

Re: Changing signs [ENDORSED]

As to your first question, be sure to stick to the greater than or equal to symbol unless the minimum is asked for, otherwise it could result in lost points. But to your second question you are correct, for example if a problem listed plus or minus six the uncertainty would be tweleve.
by Shelby Slaughter 3D
Tue Sep 27, 2016 11:47 pm
Forum: Limiting Reactant Calculations
Topic: Combustion Analysis
Replies: 1
Views: 494

Re: Combustion Analysis

First, you see in example m4 that the mystery compound contains only Carbon, Hydrogen, and Oxygen. The goal is to find the amount of each of these elements (moles). In terms of variables you need to use the mass of carbon dioxide produced and its molar mass to find the moles of CO2 (n= m/M). Once yo...
by Shelby Slaughter 3D
Sun Sep 25, 2016 8:34 pm
Forum: Empirical & Molecular Formulas
Topic: Calculating Molecular and Empirica Formulas
Replies: 5
Views: 1303

Re: Calculating Molecular and Empirica Formulas

In the audio visual module Professor Lavelle posted about empirical and molecular formulas he mentioned that a 3.89 would be fine to round up to 4 but a decimal more like 3.75 would signal that you need to multiply by something else (four). I would say 3.87 is close enough to 4 to be rounded. Usuall...

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