CHEMISTRY COMMUNITY

Melanie_Wong_1K

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...

Melanie_Wong_1K

Melanie_Wong_1K

I think it's just one or the other.

Melanie_Wong_1K

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.

Melanie_Wong_1K

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...

Melanie_Wong_1K

If you're not part of the solution, you're part of the precipitate.

Melanie_Wong_1K

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...

Melanie_Wong_1K

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.

Melanie_Wong_1K

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...

Melanie_Wong_1K

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 ...

Melanie_Wong_1K

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.

Melanie_Wong_1K

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...

Melanie_Wong_1K

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 )

Melanie_Wong_1K

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

Melanie_Wong_1K

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...

Melanie_Wong_1K

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...

Melanie_Wong_1K

I'm so tired when I'm chemistry-ing because chem is trying.

Melanie_Wong_1K

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.

Melanie_Wong_1K

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...

Melanie_Wong_1K

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...

Melanie_Wong_1K

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...

Melanie_Wong_1K

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...

CHEMISTRY COMMUNITY

Search found 22 matches

Re: "iso" naming

Re: Post All Chemistry Jokes Here

Re: Naming of molecules

Re: Determining Where Hydrogen Bonds

Re: Quiz 2 Winter 2017

Re: Post All Chemistry Jokes Here

Re: Winter 2013 Midterm #8B

Re: Positional Entropy or Thermal Entropy?

Re: New to Lavelle: Formula Sheets? [ENDORSED]

Re: Standard Enthalpy of Formation Question

Re: is h3o related to oh-

Re: How do you find the number of attachment possible?

Re: Wrting the Chemical Formula for Coordination Compounds

Re: Writing the formula of a coordination compound

Re: Drawing MO diagrams

Re: Hybridization

Re: Post All Chemistry Jokes Here

Re: Half Full d^5 and Full d^10 Subshells

Re: Formal Charge [ENDORSED]

Re: Ionization Energy

Re: Atomic Spectra Requirements [ENDORSED]

Re: Wavelength and Energy