Search found 26 matches

by Jocelyn Sandoval 3B
Thu Mar 16, 2017 9:56 am
Forum: *Alkenes
Topic: Alkenes and Functional Groups
Replies: 4
Views: 634

Re: Alkenes and Functional Groups

To add on, the double bond from the aldehyde does not need to be explicitly written because it is implied that it is there (since it corresponds to the functional group) when you add the suffix -al to the end of pentane (after dropping the e of course).
by Jocelyn Sandoval 3B
Thu Mar 09, 2017 9:40 am
Forum: Administrative Questions and Class Announcements
Topic: Quiz 3 Winter 2017
Replies: 183
Views: 15496

Re: Quiz 3 Winter 2017

For the quiz 3 preparation, why does electrophilic addition have 2 intermediates? Graphically, isn't there only 1?
by Jocelyn Sandoval 3B
Thu Mar 02, 2017 10:15 am
Forum: *Alkanes
Topic: Branched vs. Unbranched
Replies: 2
Views: 512

Re: Branched vs. Unbranched

I'm pretty sure you can draw any structure, branched or unbranched, otherwise, he would be explicit about it. As long as you have the correct number of carbons and hydrogens, you should get full points.
by Jocelyn Sandoval 3B
Thu Feb 23, 2017 9:53 am
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Galvanic Cells
Replies: 4
Views: 358

Re: Galvanic Cells

Also,just know that the metals should be transition metals when using them as electrodes.
by Jocelyn Sandoval 3B
Wed Feb 15, 2017 10:37 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagram
Replies: 11
Views: 755

Re: Cell Diagram

I think that there is a specific order in which you should have them inside of the diagram. The aqueous solution should be closest to the salt bridge, which is represented by "II". Then, I believe that the liquid goes after that and then its gas. Solids are the last ones.
by Jocelyn Sandoval 3B
Thu Feb 09, 2017 10:05 pm
Forum: Kinetics vs. Thermodynamics Controlling a Reaction
Topic: Course Reader Example
Replies: 4
Views: 401

Re: Course Reader Example

It is saying that it does occur at 25 degrees celsius & 1 atm, but very slowly.
by Jocelyn Sandoval 3B
Wed Feb 01, 2017 1:23 pm
Forum: Thermodynamic Definitions (isochoric/isometric, isothermal, isobaric)
Topic: Prep quiz 1 #3
Replies: 3
Views: 338

Re: Prep quiz 1 #3

For problem 3 you use w = -nRTln(V2/V1) because the problem states that the reaction is "reversible". If you go back to page 33 in the course reader, it explains which equations of w to use depending if the reaction is reversible or irreversible. Also, the problem tells you that pressure a...
by Jocelyn Sandoval 3B
Thu Jan 26, 2017 11:14 am
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Formulas to know
Replies: 3
Views: 594

Re: Formulas to know

If you look in the course reader at what we have learned about so far, you can assume that most formulas will be needed. Also, check the formula sheet in the course reader (pg. 125) which is the one we'll be getting for the quiz. You can check to see if there are any formulas that are not there that...
by Jocelyn Sandoval 3B
Wed Jan 18, 2017 1:13 pm
Forum: Phase Changes & Related Calculations
Topic: Calculating Enthalpy [ENDORSED]
Replies: 4
Views: 440

Re: Calculating Enthalpy [ENDORSED]

Yes, for that sample problem, the reaction enthalpy is given as -555.38 kJ, but in order to get the standard enthalpy of formation (the same as trying to get the enthalpy of one mole)of graphite, you divide by 2 as stated above.
by Jocelyn Sandoval 3B
Wed Jan 11, 2017 9:10 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Stable forms for Standard Enthalpies of Formation
Replies: 2
Views: 200

Re: Stable forms for Standard Enthalpies of Formation

I think that Dr. Lavelle was hinting at the fact that the stable form of every element should be known because he was talking about how oxygen's stable form is O2 gas and he went over other elements as a review. So in that case, I would say yes, you should memorize, it'll make things easier.
by Jocelyn Sandoval 3B
Sat Dec 03, 2016 11:11 am
Forum: Acidity & Basicity Constants and The Conjugate Seesaw
Topic: When to disregard -x in equilibrium formula?
Replies: 2
Views: 427

Re: When to disregard -x in equilibrium formula?

I think that you can assume x=0 when your Kb,Kb, or Kc value is less than 10^-5?
by Jocelyn Sandoval 3B
Sun Nov 27, 2016 7:56 pm
Forum: Bronsted Acids & Bases
Topic: Distinction between Bronsted and Lewis
Replies: 2
Views: 318

Re: Distinction between Bronsted and Lewis

Bronsted acids and bases only deal with protons--acids lose protons whereas bases gain protons. Lewis acids and bases deal with electrons--acids accept electrons and bases donate electrons.
by Jocelyn Sandoval 3B
Wed Nov 16, 2016 8:50 pm
Forum: Administrative Questions and Class Announcements
Topic: Electron configuration of molecules
Replies: 1
Views: 552

Re: Electron configuration of molecules

It might depend on your TA, but in the course reader, there is an example where you have: (σ2s)^2(σ*2s)^2(σ2pz)^2(π2p)^4(π*2p)^2. It's on page 109.
by Jocelyn Sandoval 3B
Fri Nov 11, 2016 1:27 pm
Forum: Naming
Topic: Roman numeral [ENDORSED]
Replies: 3
Views: 365

Re: Roman numeral [ENDORSED]

The roman numeral usually goes after the metal at the end in parenthesis and it gives the metal's oxidation state, which is basically the charge of the metal. In order to figure this out, you have to look at the charge of what is given and determine what charge of the metal would add up to that char...
by Jocelyn Sandoval 3B
Wed Nov 02, 2016 2:50 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Square Pyramidal
Replies: 2
Views: 368

Re: Square Pyramidal

Well since there is a lone pair, it causes the bonds on the sides to push down making them less than 90 degrees.
by Jocelyn Sandoval 3B
Wed Oct 26, 2016 7:31 pm
Forum: Resonance Structures
Topic: Resonance Course Reader Example
Replies: 2
Views: 341

Re: Resonance Course Reader Example

You would only draw all of the resonance structures if you are asked to. Otherwise, if you were asked just to draw one structure, it would be best to draw the most stable one, but as long as you show that you can draw the Lewis Structure, I think you should be fine, so don't worry, the question shou...
by Jocelyn Sandoval 3B
Wed Oct 26, 2016 7:25 pm
Forum: Ionic & Covalent Bonds
Topic: Ionic Characters
Replies: 5
Views: 614

Re: Ionic Characters

Also, you can determine the ionic character of a molecule by looking at the periodic table. The farther away the elements are, the greater the ionic character and vice versa for covalent character; the closer the elements, the greater the ionic character.
by Jocelyn Sandoval 3B
Wed Oct 26, 2016 7:22 pm
Forum: Lewis Structures
Topic: Lewis Structure Octet Rule Exceptions
Replies: 3
Views: 587

Re: Lewis Structure Octet Rule Exceptions

It a good "rule of thumb" to know that anything after Carbon needs an octet. P, S, Cl and beyond can have more than 8 electrons because of the d block in the 3rd period.
by Jocelyn Sandoval 3B
Thu Oct 20, 2016 2:48 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Lewis structures
Replies: 11
Views: 1328

Re: Lewis structures

At one of the review sessions, the UA said that you're better off when the FC of the center atom is 0.
by Jocelyn Sandoval 3B
Thu Oct 20, 2016 2:43 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: General Rules on Writing e- Configurations [ENDORSED]
Replies: 2
Views: 433

Re: General Rules on Writing e- Configurations [ENDORSED]

Well if you are looking for "general rules", it would be best to follow Hund's Rule and the Aufbau Principle because they tell you how you should be filling in the orbitals, which will make it easier for you to write the electron configuration.
by Jocelyn Sandoval 3B
Wed Oct 12, 2016 9:13 pm
Forum: Empirical & Molecular Formulas
Topic: Quiz 1 Preperation Problem #2
Replies: 2
Views: 375

Re: Quiz 1 Preperation Problem #2

Hey Jazmin!
Yes, just add the percentages and subtract from 100% to get X%.
by Jocelyn Sandoval 3B
Sat Oct 08, 2016 2:20 pm
Forum: Photoelectric Effect
Topic: The equation (pg. 13 of textbook) [ENDORSED]
Replies: 1
Views: 257

Re: The equation (pg. 13 of textbook) [ENDORSED]

Hey!
So the formula is basically saying
kinetic energy= energy of a photon - work function or threshold energy

In other words,
"1/2mv^2" is what is used to find the kinetic energy.
"hv" is the energy of the photon.
"Φ" is the work function.

Hope this helps!
by Jocelyn Sandoval 3B
Fri Oct 07, 2016 9:42 pm
Forum: Significant Figures
Topic: When to Apply Sig Figs [ENDORSED]
Replies: 2
Views: 466

Re: When to Apply Sig Figs [ENDORSED]

Also, to check if you have the right amount of sig figs, you can look at the number of sig figs that the problem started with.
by Jocelyn Sandoval 3B
Thu Sep 29, 2016 8:38 pm
Forum: General Science Questions
Topic: Rusty on High School Chem [ENDORSED]
Replies: 113
Views: 64194

Re: Rusty on High School Chem [ENDORSED]

Yeah, its been a while since I took Chem and my teacher was not the best, so there are some fundamentals that I learned through Professor Lavelle's modules. (Thanks Professor!) I would recommend going to office hours whenever you feel like lost or super confused. You can go to the Professor's hours ...
by Jocelyn Sandoval 3B
Sun Sep 25, 2016 4:42 pm
Forum: Administrative Questions and Class Announcements
Topic: Homework Assignment?
Replies: 7
Views: 771

Re: Homework Assignment?

If you look at your syllabus under "Review of Physical and Chemical Principles", there is a list of problems that we are supposed to do for homework. He's referring to M21 in that section.
by Jocelyn Sandoval 3B
Sun Sep 25, 2016 4:36 pm
Forum: Student Social/Study Group
Topic: Rieber Hall 14A Study Group (Fall 2016)
Replies: 49
Views: 4276

Re: Rieber Hall 14A Study Group (Fall 2016)

I live in Rieber Hall and I am interested. :)

Go to advanced search