Search found 22 matches
- Thu Mar 16, 2017 5:18 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Saying Thank You to Dr. Lavelle
- Replies: 490
- Views: 559798
Re: Saying Thank You to Dr. Lavelle
Dr. Lavelle, Thank you so much for all that you have done these past two quarters in chemistry. You have been such a wonderful and resourceful professor and I have learned so much being in your class. It has been such a great two quarters knowing that I had a professor that genuinely cared about stu...
- Thu Mar 09, 2017 9:15 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3623086
Re: Post All Chemistry Jokes Here
I asked the guy sitting next to me if he had any Sodium Hypobromite…
He said NaBrO
He said NaBrO
- Thu Mar 02, 2017 5:45 pm
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Nucleophile & Electrophile
- Replies: 1
- Views: 460
Nucleophile & Electrophile
Why is CH3Cl considered an electrophile (electron deficient) when chlorine has six electrons around it?
- Thu Feb 23, 2017 6:57 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3623086
Re: Post All Chemistry Jokes Here
What is the chemical formula for banana?
BaNa2
BaNa2
- Sun Feb 19, 2017 9:07 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3623086
Re: Post All Chemistry Jokes Here
Are all my jokes too basic for you? Why is there no reaction?
- Tue Feb 07, 2017 10:32 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Winter 2015 Midterm question 2and 3c
- Replies: 2
- Views: 630
Winter 2015 Midterm question 2and 3c
The question asks you to calculate the standard enthalpy of formation for HI(g). I calculated the standard enthalpy without HI and got 15.52, I then subtracted it from 84 KJ/mol, but the correct way was to subtract it from 42 KJ/mol. Why is it subtracted from 42 and not 84 KJ/mol?
- Thu Feb 02, 2017 9:38 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3623086
Re: Post All Chemistry Jokes Here
I have many good chemistry jokes....
I'm just afraid they won't get a good reaction.
I'm just afraid they won't get a good reaction.
- Thu Jan 26, 2017 5:29 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Reversible vs. Irreversible
- Replies: 1
- Views: 373
Reversible vs. Irreversible
What are the differences in characteristics of a reversible system versus a irreversible system? Which one is more efficient?
- Thu Jan 19, 2017 9:53 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3623086
Re: Post All Chemistry Jokes Here
I don't trust atoms.....
I heard they make up everything.
I heard they make up everything.
- Sat Jan 14, 2017 12:54 pm
- Forum: Phase Changes & Related Calculations
- Topic: phase changes [ENDORSED]
- Replies: 3
- Views: 994
phase changes [ENDORSED]
Just to clarify, when going from up from a solid, to liquid, to gas...the result is a positive number, and when going down from a gas, to a liquid, to a solid, the result is a negative number?
- Thu Dec 01, 2016 8:59 pm
- Forum: Bronsted Acids & Bases
- Topic: Ka and Kb
- Replies: 1
- Views: 524
Ka and Kb
When a Ka and Kb are given, is it safe to always assume away the x when calculating it in the equation because they are a weak acid/weak base?
- Sun Nov 27, 2016 4:22 pm
- Forum: Properties & Structures of Inorganic & Organic Acids
- Topic: Acidity and atomic radius
- Replies: 1
- Views: 3844
Acidity and atomic radius
Why is it that as the atomic radius increases, the acidity increases?
- Sun Nov 27, 2016 4:17 pm
- Forum: Bronsted Acids & Bases
- Topic: Strong and Weak Acids
- Replies: 1
- Views: 533
Strong and Weak Acids
Are weak acids still considered to be in equilibrium even with the favoring of the products?
- Thu Nov 17, 2016 8:46 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: MO Diagram/ Bond Order (C2)^2-
- Replies: 1
- Views: 4997
Re: MO Diagram/ Bond Order (C2)^2-
The molecular diagram you would use is the Z<8 one because carbon's atomic number is 6, however when filling in the valence electrons you would use 10 because it is two carbons(C2) (4+4) with a negative 2 charge so (+2 valence electrons). The bond order of this would be calculated using the middle p...
- Thu Nov 10, 2016 6:27 pm
- Forum: Equilibrium Constants & Calculating Concentrations
- Topic: Chemical Equilibrium constant
- Replies: 1
- Views: 482
Chemical Equilibrium constant
Kc is an equilibrium constant and therefore cannot be changed. Even if the concentration is changed, the constant stays the same, however, if the temperature is changed, does the equilibrium constant change in this case?
- Thu Nov 03, 2016 5:52 pm
- Forum: Lewis Structures
- Topic: Octet rule
- Replies: 7
- Views: 1186
Re: Octet rule
Also, the central atom can only have an expanded octet if it's phosphorous and anything beyond on the periodic table because they are reaching the d-orbitals. In addition, it is also important to note that carbon always needs a full octet.
- Thu Oct 27, 2016 8:51 pm
- Forum: Sigma & Pi Bonds
- Topic: Sigma and Pi bonds vs Covalent [ENDORSED]
- Replies: 1
- Views: 503
Re: Sigma and Pi bonds vs Covalent [ENDORSED]
Yes, sigma and pi bonds are both a form of covalent bond. A sigma bond is formed when two orbitals overlap(interact) end-to-end, and pi bonds are formed when two orbitals overlap side by side.
- Thu Oct 20, 2016 9:25 pm
- Forum: Lewis Structures
- Topic: Chapter 3 Question 21 [ENDORSED]
- Replies: 2
- Views: 593
Re: Chapter 3 Question 21 [ENDORSED]
Yes that clears things up,thank you!
- Thu Oct 20, 2016 6:44 pm
- Forum: Lewis Structures
- Topic: Chapter 3 Question 21 [ENDORSED]
- Replies: 2
- Views: 593
Chapter 3 Question 21 [ENDORSED]
The question asks you write out the abbreviated electron configuration of Te^-2, the solutions manual states that the answer is [Xe], however is the answer still valid as [Kr] 5s^2 4d^10 5p^6 (with no unpaired electrons)?
- Thu Oct 13, 2016 6:11 pm
- Forum: Balancing Chemical Reactions
- Topic: Balancing Chemical equations too slow... any advice? [ENDORSED]
- Replies: 18
- Views: 3993
Re: Balancing Chemical equations too slow... any advice? [ENDORSED]
In addition, when balancing and there is an odd number of either product or reactant, try doubling (multiplying everything by 2) to make it an even number, and balance the rest of the equation from there, hopefully creating the same amount of reactants to products.
- Thu Oct 06, 2016 8:35 pm
- Forum: Properties of Electrons
- Topic: Delta E Question from the delta E= Efinal-Eintial equation [ENDORSED]
- Replies: 1
- Views: 2629
Delta E Question from the delta E= Efinal-Eintial equation [ENDORSED]
When a problem states that the electron is absorbing light, then delta E will be a positive value, and when it states that it is emitting light, delta E will be a negative value?
- Thu Sep 29, 2016 7:15 pm
- Forum: Properties of Light
- Topic: Chapter 1 homework question
- Replies: 1
- Views: 516
Chapter 1 homework question
Chapter 1 question 9 gives a chart with different values varying from frequency, wavelength, and energy of photons. Parts of the chart are blank and more specifically in the 4th row, 2.5nm is given as the wavelength. I have already figured out the frequency which is 1.2 x 10^-17 Hz and in order to f...