Search found 22 matches
- Thu Mar 09, 2017 10:33 pm
- Forum: *Cycloalkanes
- Topic: "iso" naming
- Replies: 4
- Views: 2731
Re: "iso" naming
For question 1.16 in the organic chemistry textbook, why is the answer 2-isopropyl-1,1-dimethylcyclopentane and not 1,1-dimethyl-2-isopropylcyclopentane? Following the alphabetical ordering rule This one is tricky, so you take iso- into account when alphabetizing the substituents, but not di-. Ther...
- Tue Mar 07, 2017 3:14 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3650149
- Tue Mar 07, 2017 2:57 pm
- Forum: *Alkanes and Substituted Alkanes (Staggered, Eclipsed, Gauche, Anti, Newman Projections)
- Topic: Naming of molecules
- Replies: 2
- Views: 1825
Re: Naming of molecules
I think it's just one or the other.
- Mon Feb 27, 2017 5:34 pm
- Forum: *Organic Reaction Mechanisms in General
- Topic: Determining Where Hydrogen Bonds
- Replies: 5
- Views: 1107
Re: Determining Where Hydrogen Bonds
The curved arrows are meant to model which bonds are broken or which lone pairs break off, they show which atom the electrons are moving to. An arrow with a normal head means two electrons move from the bond/lone pair while an arrow with half a head means only one electron moves.
- Tue Feb 21, 2017 2:50 pm
- Forum: Administrative Questions and Class Announcements
- Topic: Quiz 2 Winter 2017
- Replies: 160
- Views: 24934
Re: Quiz 2 Winter 2017
How is question one done from quiz 2? When you balance the reaction, you get 2 mol N2O5, so you multiply the rate of decomposition of N2O5, 2.89, by 2 to get the rate of formation of NO2. So, this would be 2(2.89)= 5.78 (mol NO2)⋅L–1⋅s–1 Does this mean the coefficient in front of the reactants does...
- Sun Feb 19, 2017 10:53 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3650149
Re: Post All Chemistry Jokes Here
If you're not part of the solution, you're part of the precipitate.
- Sat Feb 11, 2017 9:12 pm
- Forum: Appications of the Nernst Equation (e.g., Concentration Cells, Non-Standard Cell Potentials, Calculating Equilibrium Constants and pH)
- Topic: Winter 2013 Midterm #8B
- Replies: 2
- Views: 615
Re: Winter 2013 Midterm #8B
This question actually concerns both #8b and 7 of the 2013 Midterm. When you're using the Nerst Equation, how do you find n? The moles aren't given in either of the problems but the answer to #7 says n=10 and for #8b n=2. They don't seem to relate to the amount of moles in the chemical equations eit...
- Fri Jan 20, 2017 5:04 pm
- Forum: Concepts & Calculations Using Second Law of Thermodynamics
- Topic: Positional Entropy or Thermal Entropy?
- Replies: 1
- Views: 778
Re: Positional Entropy or Thermal Entropy?
I believe this equation is used to find positional/residual entropy in an isothermal system that has a reversible reaction, meaning no energy is transferred as heat and the reaction can go backwards.
- Wed Jan 18, 2017 4:42 pm
- Forum: Phase Changes & Related Calculations
- Topic: New to Lavelle: Formula Sheets? [ENDORSED]
- Replies: 3
- Views: 707
Re: New to Lavelle: Formula Sheets? [ENDORSED]
You're given a formula sheet and periodic table for each quiz, midterm, and the final. It's usually a page on the back that you can rip off to use. But it doesn't look exactly like the laminated sheet we were given with the course reader. The periodic table elements have more specific masses and the...
- Thu Jan 12, 2017 10:43 pm
- Forum: Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)
- Topic: Standard Enthalpy of Formation Question
- Replies: 3
- Views: 722
Re: Standard Enthalpy of Formation Question
The standard enthalpy of formation is related to standard reaction enthalpies . Since reactants and products can be in different states and reactions can occur at different pressures, the enthalpy can change. The standard reaction enthalpies found on pg. 17 of the course reader allow for uniformity ...
- Fri Nov 25, 2016 2:58 pm
- Forum: Conjugate Acids & Bases
- Topic: is h3o related to oh-
- Replies: 2
- Views: 3940
Re: is h3o related to oh-
Yep, H30+ and OH- are formed from H20 during autoprotolysis. One of the water atoms steals an oxygen from another water atom. The reaction is called autoprotolysis because the molecules are the same, they just transfer protons.
- Mon Nov 14, 2016 10:36 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: How do you find the number of attachment possible?
- Replies: 3
- Views: 809
Re: How do you find the number of attachment possible?
Ethylenediamine (en) is a bidentate which means it has 2 attachment sites. Diethylenetriamine (dien) is a tridentate which means it has 3 attachment sites. In the table on page 117 of the course reader, I believe every other ligand is a monodentate which means it has one attachment site except excep...
- Mon Nov 14, 2016 9:19 pm
- Forum: Shape, Structure, Coordination Number, Ligands
- Topic: Wrting the Chemical Formula for Coordination Compounds
- Replies: 3
- Views: 3020
Re: Wrting the Chemical Formula for Coordination Compounds
download.png Actually there is a rule. (Here's the URL in case the picture doesn't load, this site is super helpful for naming coordinate compounds: http://chem.libretexts.org/Core/Inorganic_Chemistry/Coordination_Chemistry/Basics_of_Coordination_Chemistry/Nomenclature_of_Coordination_Complexes )
- Mon Nov 14, 2016 9:12 pm
- Forum: Naming
- Topic: Writing the formula of a coordination compound
- Replies: 2
- Views: 895
Re: Writing the formula of a coordination compound
I searched online and found this site super helpful: http://chem.libretexts.org/Core/Inorganic_Chemistry/Coordination_Chemistry/Basics_of_Coordination_Chemistry/Nomenclature_of_Coordination_Complexes
- Thu Nov 10, 2016 1:42 pm
- Forum: *Molecular Orbital Theory (Bond Order, Diamagnetism, Paramagnetism)
- Topic: Drawing MO diagrams
- Replies: 2
- Views: 657
Re: Drawing MO diagrams
Remember that MO diagrams are supposed to show resonance structures, molecules with unpaired elections, and information about the bond energies which all depend on valence electrons and how they bond with other atoms. The important information should be in which electrons are left unpaired and drawi...
- Tue Nov 01, 2016 5:16 pm
- Forum: Hybridization
- Topic: Hybridization
- Replies: 2
- Views: 593
Re: Hybridization
The hybridization number depends on the number of bonds/valence electrons attached to the given atom. You just have to remember that double and triple bonds count as one hybridized bond. So a carbon with 4 single bonds will have a hybridization of sp^3 while a carbon with two single bonds and a doub...
- Thu Oct 27, 2016 4:26 pm
- Forum: Student Social/Study Group
- Topic: Post All Chemistry Jokes Here
- Replies: 9651
- Views: 3650149
Re: Post All Chemistry Jokes Here
I'm so tired when I'm chemistry-ing because chem is trying.
- Thu Oct 27, 2016 4:14 pm
- Forum: Octet Exceptions
- Topic: Half Full d^5 and Full d^10 Subshells
- Replies: 4
- Views: 1095
Re: Half Full d^5 and Full d^10 Subshells
There would only be an exception for the Co^2- ion which acts like Cu. It's electron configuration would then be [Ar] 3d^10 4s^1.
- Wed Oct 19, 2016 11:28 am
- Forum: Resonance Structures
- Topic: Formal Charge [ENDORSED]
- Replies: 3
- Views: 899
Re: Formal Charge [ENDORSED]
Third question: Sulfur can hold more electrons in it's valence shell because it borrows space from a d-orbital. When the electrons don't fit in the p-orbital anymore, it just adds the electrons to the next available orbital (3d). However, you can only do this if the atom is in the 3rd period or lowe...
- Fri Oct 14, 2016 4:24 pm
- Forum: Ionic & Covalent Bonds
- Topic: Ionization Energy
- Replies: 7
- Views: 1572
Re: Ionization Energy
Use the periodic table. Remember that right side and upper elements have higher ionization energies, so the upper right hand corner of the table has elements with the highest ionization energies and the lower left hand corner has the lowest. So if you're comparing two, say Sulfur and Fluorine, Sulfu...
- Wed Oct 05, 2016 10:41 am
- Forum: Properties of Electrons
- Topic: Atomic Spectra Requirements [ENDORSED]
- Replies: 3
- Views: 847
Re: Atomic Spectra Requirements [ENDORSED]
I think it's better to know the general ranges of the Infrared, Visible, and Ultraviolet regions of the electromagnetic spectrum just because those are used the most. Here are all the ranges just in case: radio waves - 10 cm microwaves - 1 mm infrared - greater than 800 nm, about 1000 nm visible - 4...
- Mon Sep 26, 2016 10:00 pm
- Forum: Properties of Light
- Topic: Wavelength and Energy
- Replies: 3
- Views: 1873
Re: Wavelength and Energy
For 1.23 remember that wavelength=speed of light constant/frequency, and frequency = Energy/Planck's constant, so if Y is wavelength (because I can't figure out how to type lambda) Y=c/v and v=E/h. So you just have to set it up as Y=hc/E and subsitute 6.626x10^(-34) for h, 3.00x10^(8) for c, and plu...