Search found 24 matches

by Shushanna S 3F
Thu Mar 16, 2017 12:11 pm
Forum: *Constitutional and Geometric Isomers (cis, Z and trans, E)
Topic: Difference between cis and Z, and trans and E
Replies: 4
Views: 730

Re: Difference between cis and Z, and trans and E

E and Z are part of the IUPAC naming guidelines. But they mean the same thing.
by Shushanna S 3F
Thu Mar 16, 2017 12:09 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: 2013 Final Practice Exam, Question 4a; n=?
Replies: 6
Views: 515

Re: 2013 Final Practice Exam, Question 4a; n=?

The iron goes from an oxidation state of 0 to +2 (and the oxygen goes from 0 to -2). And since there are two moles of iron and oxygen, 2*2electrons=4 electrons. Hope that helps!
by Shushanna S 3F
Thu Mar 16, 2017 11:51 am
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Question 4 2013 Practice Final
Replies: 1
Views: 291

Re: Question 4 2013 Practice Final

The iron goes from an oxidation state of 0 to +2 (and the oxygen goes from 0 to -2). And since there are two moles of iron and oxygen, 2*2electrons=4 electrons. Hope that helps!
by Shushanna S 3F
Thu Mar 09, 2017 12:01 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012100

Re: Post All Chemistry Jokes Here

I never knew CH3CH2CH3 enjoyed pain.



(Propane... Pro-pain. Ha)
by Shushanna S 3F
Sun Mar 05, 2017 5:42 pm
Forum: *Organic Reaction Mechanisms in General
Topic: Collision Orientation
Replies: 1
Views: 223

Re: Collision Orientation

Sometimes you can guess from the structures of the reactants. For example if one of the reactants is trigonal planar and it is the central atom that is going to be involved in the reaction, then it makes sense that the other reactant will form a bond from either the top or the bottom of that molecul...
by Shushanna S 3F
Sun Feb 26, 2017 7:48 pm
Forum: *Electrophiles
Topic: Reactions Involving Nucleophiles and Electrophiles
Replies: 1
Views: 206

Re: Reactions Involving Nucleophiles and Electrophiles

I don't see why that would be a requirement for the reaction...but in the course reader it says that for our purposes of introduction to o-chem, "we will focus mainly on reactions that involve carbon-carbon double bonds"(80).
by Shushanna S 3F
Sun Feb 19, 2017 5:28 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012100

Re: Post All Chemistry Jokes Here

Friend texts me: Hey do you think we can hang out?

Me: NOBr, I'm busy.

*starts laughing at own joke*
by Shushanna S 3F
Tue Feb 14, 2017 12:39 pm
Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
Topic: Nernst Equation [ENDORSED]
Replies: 4
Views: 486

Re: Nernst Equation [ENDORSED]

Faraday's constant is actually 96,485.3. There's a typo on the back of the laminated periodic table. I checked in our lecture notes for the course reader and it's given as 96,485. (I think the .3 was left off but you can double check.)
by Shushanna S 3F
Tue Feb 07, 2017 7:53 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012100

Re: Post All Chemistry Jokes Here

I'm so salty, you could you could make a battery out of me.
by Shushanna S 3F
Sat Jan 28, 2017 4:10 pm
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Homework Problem 8.37
Replies: 1
Views: 320

Re: Homework Problem 8.37

You divide the amount of heat by the number of moles to get 8.22 kJ/mol. This is because the problem tells you that that's the amount of energy it takes to for that amount of moles of methane to vaporize, so all you have to do is put in the the standard kJ per mole notation.
by Shushanna S 3F
Mon Jan 23, 2017 6:19 am
Forum: Phase Changes & Related Calculations
Topic: Homework 8.87
Replies: 2
Views: 430

Re: Homework 8.87

That makes perfect sense. Thank you.
by Shushanna S 3F
Sun Jan 22, 2017 9:38 pm
Forum: Phase Changes & Related Calculations
Topic: Homework 8.87
Replies: 2
Views: 430

Homework 8.87

The question asks: "How much heat is required to convert a 42.30g block of ice at -5.042 degrees C into water vapor at 150.35 degrees C?" I know that I have to factor in the change in enthalpy due to the two phase changes. I converted the grams of H2O to moles and multipled that to the del...
by Shushanna S 3F
Thu Jan 19, 2017 10:13 am
Forum: Thermodynamic Systems (Open, Closed, Isolated)
Topic: Work on a System [ENDORSED]
Replies: 3
Views: 508

Re: Work on a System [ENDORSED]

A simple way I think about this is: if you're in a box and pushing the roof away from you to make more space, then you (the system) is doing work on the surrounding (because it takes effort to push the roof). If the roof is pushing down on you (even though you resist) the roof (surrounding) is doing...
by Shushanna S 3F
Wed Jan 11, 2017 7:41 pm
Forum: Student Social/Study Group
Topic: Post All Chemistry Jokes Here
Replies: 7569
Views: 1012100

Re: Post All Chemistry Jokes Here

What did the crazy chemist do with the bulls at rodeo?

He Rhodium. *ba dum tss*

(thought of this myself tyvm)
by Shushanna S 3F
Tue Nov 29, 2016 10:48 am
Forum: Ideal Gases
Topic: Gas Equation
Replies: 1
Views: 292

Re: Gas Equation

If you're referring to Gas Constant R: "If R=8.206x10^-2 L.atm.K^-1.mol^-1 is used then the answer is in atm and it can be left as atm. If R=8.314x10^-2 L.bar.K^-1.mol^-1 is used then the answer is in bar which is perfect."

This is on page 9 of the Chemical Equilibra course reader notes.
by Shushanna S 3F
Fri Nov 25, 2016 8:31 am
Forum: Bronsted Acids & Bases
Topic: Strong vs. weak
Replies: 3
Views: 482

Re: Strong vs. weak

Some of them you just have to memorize. There should be a table in the book (either in Fundamentals or in this chapter) with a list of strong acids and bases.
by Shushanna S 3F
Mon Nov 14, 2016 9:14 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: Ligands [ENDORSED]
Replies: 2
Views: 321

Re: Ligands [ENDORSED]

You can figure out by drawing a complete Lewis structure, but since that takes a while--especially for something like diethylenetriamine (it makes three bonds, so it's tridentate), it's better just to memorize the chart of ligands he gave us.
by Shushanna S 3F
Tue Nov 08, 2016 3:11 pm
Forum: Shape, Structure, Coordination Number, Ligands
Topic: How to determine if ligands are polydentates?
Replies: 2
Views: 443

Re: How to determine if ligands are polydentates?

What kind of dentate a ligand is depends not only on the number of atoms with lone pairs, but also on the geometry. For example, the best structure for a bidentate molecule is the half ring. With the atoms with lone pairs separated by two spacers.
by Shushanna S 3F
Fri Oct 28, 2016 8:06 pm
Forum: Lewis Structures
Topic: Number of Bonds
Replies: 2
Views: 342

Re: Number of Bonds

@Lauren: Nitrogen usually makes 3 bonds and carbon usually makes 4 bonds.

@JELCI: Knowing the number of bonds an atom tends to make helps with the placement of atoms in more complex molecules and is usually a result of the number and arrangement of valence electrons of the atom.
by Shushanna S 3F
Fri Oct 21, 2016 6:39 pm
Forum: Determining Molecular Shape (VSEPR)
Topic: Angles of molecular shapes
Replies: 5
Views: 783

Re: Angles of molecular shapes

If I recall correctly, these angles are experimentally determined, so I don't think we can calculate them. Just something we need to know.
by Shushanna S 3F
Wed Oct 12, 2016 7:57 pm
Forum: Wave Functions and s-, p-, d-, f- Orbitals
Topic: Question 2.19 part b and c [ENDORSED]
Replies: 6
Views: 651

Re: Question 2.19 part b and c [ENDORSED]

For #19, one thing you need to know is that n (principle quantum number) = shell, l (angular momentum quantum number) = subshell, and that m sub l (the magnetic quantum number)=orbital. You know that m sub l = l, l-1,... -l. Using the value of l, you find the values of m sub l and count how many val...
by Shushanna S 3F
Tue Oct 04, 2016 11:57 am
Forum: Bohr Frequency Condition, H-Atom , Atomic Spectroscopy
Topic: 1.57 [ENDORSED]
Replies: 5
Views: 893

Re: 1.57 [ENDORSED]

@Kevin Tam 1D I tried your method, but got 511nm instead of 397nm (the answer in the back of the book). But I agree with your logic...so I'm puzzled too. @Preston_Dang_1C I also tried your method just for comparison and got 434nm, which once again, isn't the correct answer of 397nm. What are we miss...
by Shushanna S 3F
Mon Oct 03, 2016 7:30 pm
Forum: DeBroglie Equation
Topic: Question about baseball wavelenghts [ENDORSED]
Replies: 3
Views: 662

Re: Question about baseball wavelenghts [ENDORSED]

Also, something else Dr. Lavelle said is that we cannot detect anything that is smaller than 10^-15. Usually an electron's wavelength is less than that so we can detect it--unlike the baseball.
by Shushanna S 3F
Mon Sep 26, 2016 9:01 pm
Forum: Molarity, Solutions, Dilutions
Topic: Fundamentals G5
Replies: 6
Views: 1059

Re: Fundamentals G5

Yeah that's correct.

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