Search found 20 matches

by Da_Rhee_1O
Wed Mar 15, 2017 9:58 am
Forum: *Alkenes
Topic: Numbering the Double Bond
Replies: 3
Views: 618

Re: Numbering the Double Bond

It can go both ways. 2 pentene and pent-2-ene both signify that the double bond is on the 2nd carbon of the parent chain. 2 pentene is a simpler way to say it.
by Da_Rhee_1O
Mon Mar 06, 2017 3:32 pm
Forum: *Cycloalkanes
Topic: Cyclo-
Replies: 7
Views: 882

Re: Cyclo-

One way to tell when to draw cycloalkane is when when the number of hydrogen atoms is exactly twice the number of carbon atoms present (thus the formula for cycloalkane: CnH2n). The formula for cycloalkene varies on how many double bonds are present in the compound. 1 double bond= CnH(2n-2) 2 double...
by Da_Rhee_1O
Fri Mar 03, 2017 3:39 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Substituent Naming
Replies: 3
Views: 359

Re: Substituent Naming

In the example, 4-ethyl-2, 2-dimethyl-hexane, can someone explain the concept of which number refers to what in the chain? For instance, explanation on why there are two 2's in front of dimethyl.
by Da_Rhee_1O
Fri Mar 03, 2017 3:10 pm
Forum: *Electrophiles
Topic: ambident nucleophiles
Replies: 3
Views: 707

Re: ambident nucleophiles

The definition of an ambident nucleophile is a nucleophile which can have more than one site by which they can donate electrons. This being said, Rishi is correct in saying that either the N or the S can donate. The resonance structure allows the flexibility in deciding whether the N or the S can do...
by Da_Rhee_1O
Mon Feb 13, 2017 5:26 pm
Forum: Balancing Redox Reactions
Topic: Writing Cell Diagrams
Replies: 5
Views: 793

Re: Writing Cell Diagrams

I took a look again and confirmed with someone that for the order, the element before it is reduced is placed first, then the reduced form of it comes afterwards. There is an example in the coursereader on page 48 where Fe3+(aq) is written before Fe2+(aq). And it also looks like this is the case for...
by Da_Rhee_1O
Sun Feb 12, 2017 1:22 am
Forum: Balancing Redox Reactions
Topic: Writing Cell Diagrams
Replies: 5
Views: 793

Re: Writing Cell Diagrams

I am not too entirely positive, but I was also told that the general notation is what is more important than the order of the aqueous ions.
by Da_Rhee_1O
Mon Jan 30, 2017 6:32 pm
Forum: Administrative Questions and Class Announcements
Topic: Fall 2016 Finals Still Available?
Replies: 5
Views: 686

Fall 2016 Finals Still Available?

I recall that the email from last quarter stated: " Final exams will be available 3rd week Winter Quarter from 4006 Young Hall."

I know that it is now Week 4 but are we able to still pick up our final exams?
by Da_Rhee_1O
Tue Jan 24, 2017 11:24 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: Heat Capacity of Gases
Replies: 2
Views: 360

Re: Heat Capacity of Gases

In case not, there is a neat trick that you can just memorize to find the Cp and Cv for monoatomic and diatomic molecules: for monoatomic molecules the Cp and Cv can be calculated as: (5/2)R and (3/2)R respectively. for diatomic molecules the Cp and Cv can be calculated as: (7/2)R and (5/2)R respect...
by Da_Rhee_1O
Wed Jan 18, 2017 3:06 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Heat capacity [ENDORSED]
Replies: 5
Views: 708

Re: Heat capacity [ENDORSED]

As for calculations, these are the simple equations/ratios needed in order to find the heat capacity at constant pressure and volume for monoatomic molecules, respectively:
Cp = 5/2(R)
Cv = 3/2(R)

These are the ratios for diatomic molecules:
Cp = 7/2(R)
Cv = 5/2(R)
by Da_Rhee_1O
Thu Jan 12, 2017 5:11 pm
Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
Topic: Standard Enthalpy of Form; Balanced Eqns
Replies: 2
Views: 216

Re: Standard Enthalpy of Form; Balanced Eqns

Regarding standard enthalpy of formation, it is the change in enthalpy when ONE mole of the substance you are trying to find is formed in the standard state. It is important that the rest of the equation is balanced according to having only one mole of the substance. That is why fractions may be seen.
by Da_Rhee_1O
Fri Dec 02, 2016 12:59 am
Forum: Ionic & Covalent Bonds
Topic: Polarizability
Replies: 2
Views: 307

Re: Polarizability

Outer electrons are more loosely held as an anion gets bigger/larger. Therefore, this makes it easier for a cation to distort the outer electrons. Hence, larger anions have more polarizability.
by Da_Rhee_1O
Wed Nov 16, 2016 9:25 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: Heteronuclear Diatomic Molecules: Electronegativity
Replies: 1
Views: 255

Heteronuclear Diatomic Molecules: Electronegativity

In heteronuclear diatomic molecules, I understand that the s and p levels for the atom with higher electronegativity will be drawn lower than the s and p levels for the other atom. However, what is the exact reason why higher electronegative atoms have lower energy levels?
by Da_Rhee_1O
Thu Nov 10, 2016 3:44 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Chelates
Replies: 2
Views: 390

Re: Chelates

Chelates are rings that form as a result of polydentate ligands bonding to a metal ion.
by Da_Rhee_1O
Thu Nov 03, 2016 3:51 pm
Forum: Hybridization
Topic: Polar vs Non polar
Replies: 5
Views: 978

Re: Polar vs Non polar

One thing to also remember is that lone pairs have a higher electron density and are more localized than bonding electrons, therefore making the molecule polar. Single lone pairs are helpful to look out for when distinguishing whether the molecule is polar or non-polar.
by Da_Rhee_1O
Tue Oct 25, 2016 10:01 pm
Forum: Lewis Structures
Topic: Lewis Structure for Ch 3. 67
Replies: 1
Views: 310

Lewis Structure for Ch 3. 67

Could someone explain why the Be in BeCl2 (in homework problem #67 in Chapter 3) deviates from the octet rule? The Lewis structure drawn for BeCl2 in the solutions manual shows that there are only 4 electrons surrounding the beryllium (Be). How could that be?
by Da_Rhee_1O
Thu Oct 20, 2016 8:29 pm
Forum: Lewis Structures
Topic: Drawing Lewis Structures [ENDORSED]
Replies: 2
Views: 370

Re: Drawing Lewis Structures [ENDORSED]

Just something to remember is that carbon tends to always be the central atom whereas hydrogen is always bonding to another atom. And when I went to a PFL session, the UA said that in molecules with more than one central atom, just looking at the chemical composition (for example: CH3SH) will help t...
by Da_Rhee_1O
Thu Oct 13, 2016 10:31 pm
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Electron Affinity
Replies: 6
Views: 616

Re: Electron Affinity

What does the course reader mean when next to the electron affinity equation it says X(g) + e- -> X-(g) "DEFINED AS" Eea = E(X)(g) - E(X-)(g)

Is this the same equation rephrased differently? Just wanted clarification, please.
by Da_Rhee_1O
Thu Oct 06, 2016 10:52 pm
Forum: Photoelectric Effect
Topic: Photoelectric Effect [ENDORSED]
Replies: 12
Views: 1444

Re: Photoelectric Effect [ENDORSED]

Yes, the quizzes should be done in pen. Dr. Lavelle mentioned himself that anything being graded must be done in pen. So I am not sure about the self-quizzes but for the last quiz without the answers provided, definitely do the problems in ink. Hope this helps!
by Da_Rhee_1O
Mon Sep 26, 2016 9:59 pm
Forum: SI Units, Unit Conversions
Topic: Review Principles question E15
Replies: 8
Views: 953

Re: Review Principles question E15

Thank you! The attachment will definitely come in handy~
by Da_Rhee_1O
Mon Sep 26, 2016 9:04 pm
Forum: SI Units, Unit Conversions
Topic: Review Principles question E15
Replies: 8
Views: 953

Re: Review Principles question E15

A quick question regarding the part on "charges." I understand that we were able to find out that the charge of the metal should be 2+ and thus, sulfide's charge should be 2-. However, I did not know that OH has a charge of 1-. Is there a way to know the charge of a certain element just by...

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