Search found 20 matches

by Liz Pecora 1L
Tue Mar 08, 2016 3:03 pm
Forum: *Amines
Topic: Alkyl Groups
Replies: 1
Views: 557

Re: Alkyl Groups

Here is an example of two N in a chain,
H2N-CH2-CH2-CH2-CH2-NH2 1,4-Butandiamine

If there are substituents coming off each N I'm not sure but I'm guessing you would just name one N as a substituent with whatever chain it has attached to it.
by Liz Pecora 1L
Mon Mar 07, 2016 12:56 am
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: CR Page 107 Ex. 1 Cis/Trans
Replies: 1
Views: 288

Re: CR Page 107 Ex. 1 Cis/Trans

When the double bond is at the beginning of the chain it only has H on one end and the other end will have the rest of the Carbon chain. Since the two bonds are both H on the end, its neither Cis or Trans.
by Liz Pecora 1L
Sun Feb 28, 2016 9:28 pm
Forum: *Alcohols
Topic: tertiary alcohol
Replies: 2
Views: 366

Re: tertiary alcohol

Whether it is primary, secondary or tertiary,

First- find the OH,
Second- look at the carbon that OH is attached to
Third- Count how many Carbons are attached to that carbon.

In your picture OH is attached to a carbon that is bonded to 3 other carbons so, it is tertiary.
by Liz Pecora 1L
Sat Feb 20, 2016 11:42 pm
Forum: *Nucleophiles
Topic: nucleophiles
Replies: 2
Views: 349

Re: nucleophiles

All Nucleophiles are lewis bases, they donate electrons. Nucleophiles have excess electrons and OH- also have excess Electrons. Electrophiles want more electrons, so would H+.
by Liz Pecora 1L
Thu Feb 11, 2016 5:04 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Potential Signs
Replies: 1
Views: 341

Re: Cell Potential Signs

If there are two negative E o then you want to make the more negative # the anode. Cathode - anode Ex. -50 and -70 Use -50 as the Cathode and and -70 as the anode. -50-(-70)= +20 Let's say the Rxn was listed in the table as A + (aq) + e - ----> A (s) = -70 Then you would flip the equ...
by Liz Pecora 1L
Sat Feb 06, 2016 7:33 pm
Forum: Galvanic/Voltaic Cells, Calculating Standard Cell Potentials, Cell Diagrams
Topic: Cell Diagrams
Replies: 1
Views: 244

Re: Cell Diagrams

It doesn't matter which one you use.
by Liz Pecora 1L
Tue Jan 26, 2016 10:55 pm
Forum: Concepts & Calculations Using Second Law of Thermodynamics
Topic: Entropy Calculations (9.1)
Replies: 5
Views: 1853

Re: Entropy Calculations (9.1)

9.1 A human body generates heat at the rate of about 100. W (1 W 1 J . s-'). (a)At what rate does your body heat generate entropy in your surroundings, taken to be at 20.0 C? (b)How much entropy do you generate each day? (c)Would the entropy generated be greater or less if you were in a room kept a...
by Liz Pecora 1L
Sat Jan 23, 2016 1:24 pm
Forum: Heat Capacities, Calorimeters & Calorimetry Calculations
Topic: 8.23 Energy put into heat calorimeter and water
Replies: 1
Views: 279

8.23 Energy put into heat calorimeter and water

Q8.23) A colorimeter was calibrated with an electric heater, which supplied 22.5Kj of energy as heat to the calorimeter and increased the temperature of the Calorimter and its water bath from 22.45 o C to 23.97 o C. What is the heat capacity of the calorimeter? My question, why ins't the water bath ...
by Liz Pecora 1L
Sun Jan 17, 2016 1:03 pm
Forum: Phase Changes & Related Calculations
Topic: State and Path functions
Replies: 2
Views: 393

Re: State and Path functions

Because entropy is a state function, the change in entropy of a system is independent of the path between its initial and final states. This independence means that, if we want to calculate the entropy clifference between a pair of states joined by an irreversible path, we can look for a reversible ...
by Liz Pecora 1L
Fri Jan 08, 2016 8:53 pm
Forum: Phase Changes & Related Calculations
Topic: Exothermic vs. Endothermic
Replies: 8
Views: 1715

Re: Exothermic vs. Endothermic

I feel its easy to remember that, to the system, everything around it is the surroundings not just another object such as the knee. The Ice pack in that example will be taking in energy (endothermic) leaving the outside or its surroundings feeling cold. the knee being there is just a source of heat.
by Liz Pecora 1L
Wed Dec 02, 2015 11:03 pm
Forum: General Science Questions
Topic: Chemistree
Replies: 1
Views: 527

Chemistree

Chemistree.png
Chemistree


Happy Holidays!
by Liz Pecora 1L
Mon Nov 23, 2015 6:05 pm
Forum: Formal Charge and Oxidation Numbers
Topic: Formal Charge quick count video
Replies: 1
Views: 461

Formal Charge quick count video

Lines and dots.mp4 [ 434.92 MiB | Viewed 461 times ]

Lines and dots walk through
by Liz Pecora 1L
Thu Nov 19, 2015 10:24 am
Forum: Equilibrium Constants & Calculating Concentrations
Topic: 2013 Quiz 3 Preparation #10
Replies: 10
Views: 1071

Re: 2013 Quiz 3 Preparation #10

So in the ICE box, the initial concentrations for Br2 and Cl2 are 0 instead of 4.9 and 7.9? Meaning, K= (.54+2x)2/(-x)(-x)?
by Liz Pecora 1L
Sun Nov 08, 2015 9:35 pm
Forum: Resonance Structures
Topic: Preferred Resonance Structure of Molecule
Replies: 3
Views: 951

Re: Preferred Resonance Structure of Molecule

Wouldn't you draw a structure that had an unfavorable formal charge and then point to the structures with the lowest energy as the best option?
by Liz Pecora 1L
Thu Oct 29, 2015 10:41 am
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: OF+
Replies: 2
Views: 3742

Re: OF+

Thank you for the detailed answer!
When we write the Molecular Orbital theory out, we put them in sigma or pi bonds but lone pair electrons aren't in a bond. It it just that the MO cannot tell you which e- are bonds and which are lone pairs so we just list them all in sigma and pi bonds?
by Liz Pecora 1L
Tue Oct 27, 2015 9:45 pm
Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
Topic: OF+
Replies: 2
Views: 3742

OF+

Can someone explain this, For: OF+ BO=2 for OF+ But you cant write the Lewis structure that reflects this. This is really confusing me. I know the example of O 2 was given in class but I still don't understand the proper way to write the Lewis structure if the BO tells us there are two unpaired e-.
by Liz Pecora 1L
Wed Oct 21, 2015 12:36 am
Forum: Electron Configurations for Multi-Electron Atoms
Topic: Configuration differences example. Pt & Nb
Replies: 1
Views: 231

Configuration differences example. Pt & Nb

Why is platinum [Xe]4f 14 5d 9 6s 1 ? Why isn't the 6s e- pulled to the 5d to fulfill the set Or, why Niobium ([Kr]4d 4 4s 1 takes an e- from the 5s just to achieve an unpaired electron in both the 4d and 5s? Is there another way to keep track of these different configurations? Its just about relati...
by Liz Pecora 1L
Wed Oct 14, 2015 10:43 pm
Forum: Empirical & Molecular Formulas
Topic: Self test Quiz 1
Replies: 1
Views: 370

Self test Quiz 1

Can you use coefficients in chemical formulas? Ex. Q2 on the self quiz 1. Why couldn't C6H10O be written as 2C6H10O? I know the answer is C12H20O2, I was just wondering.
by Liz Pecora 1L
Sun Oct 11, 2015 9:31 am
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Nodes
Replies: 2
Views: 317

Re: Nodes

So I guess I was kind of mislead because the orbitals are referred to as "shells" as if they were hollow but the electron can be found anywhere from the nucleus to the outer most area of the shell and this distribution is in equal amounts correct? Doesn't the probability of finding an elec...
by Liz Pecora 1L
Wed Sep 30, 2015 6:04 pm
Forum: Properties of Light
Topic: Diffraction and Incident Light
Replies: 6
Views: 769

Re: Diffraction and Incident Light

If a single photon is sent through the slit, will it still have a diffraction pattern or will only one photon will be detected? Will it diffract on itself?

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