CHEMISTRY COMMUNITY

nick_pantoja_3G

Dr. Lavelle,
Thank you for all the resources and knowledge that you have given us. You have not only been able to make chemistry interesting but also easy to understand!
Sincerely,
Nick Pantoja

nick_pantoja_3G

For a molecule that has 3 different subsitituients on the carbon that you are analyzing for the newsman projection, do you have tp draw the substituents in a specific order. Like would you have to look at the molecule structure.

nick_pantoja_3G

do we only need to know eclipsed and staggered conformations for ethane and butane? if not, are the other conformations the same as those we learned for those two? thanks

nick_pantoja_3G

I also believe if it is talking about activation energy then the reaction profile will be energy on the y-axis, while if they give you standard free energy of activation then the y axis would be gibbs free energy

nick_pantoja_3G

i know that electrophile (based on the root words) likes electrons, does that mean it is positive and wants a negative value, or that its negative and wants a positive value. thank you.

nick_pantoja_3G

What in a question tells you if a kinetic reaction is zero order, 1st order, or 2nd order?

nick_pantoja_3G

To memorize what is getting oxidized and reduced.. follow the acronym LEO goes GER.
Loses
Electrons
Oxidized

Gains
Electrons
Reduction

This is important to get right because if you mix them up then the whole problem is incorrect.

nick_pantoja_3G

I have a general question on how to differentiate between what's being reduced and what is being oxidized. So within a chemical equation, how can you tell what the oxidizing number is from the equation and then determine if it is being reduced or oxidized?

nick_pantoja_3G

THANK YOU SO MUCH! that solved the problem. that makes so much sense.

nick_pantoja_3G

In a particular problem on the homework, it gave the values of delta s subscript m, when trying to calculate gibbs free energy, (specifically the change in entropy within the equation) however the chemical equation had 2 moles of it so the solution divided the given delta s values by 2. why is that?

nick_pantoja_3G

What does isothermic reversible expansion mean?

nick_pantoja_3G

What is the main clue on whether to use bond enthalpies vs standard enthalpies of formation in a problem to calculate the net enthalpy? I feel that both are similar and I'm not sure what to look for as in approaching the problem.

nick_pantoja_3G

in one homework assignment, it gave a compound Ba(OH)₂ and then it said that the moles of OH was .033 moles however when using ice tables, it used .066. did it use .066 bc there were two things of it?

nick_pantoja_3G

yes and so is the dissociation constant

nick_pantoja_3G

When the z<8 and if the M.O. is heteronuclear, the order is placed as such: sigma, anti bonding sigma, pi bonds, sigma, pi anti bonds, and then sigma anti bonds for z>8: sigma, sigma antibond, sigma, pi, pi antibond, sigma. if there is a heteronuclear compound the one that is more electronegative is...

nick_pantoja_3G

And with those Q and K values, you will be able to compare and see which side is favored.

nick_pantoja_3G

In molecular theory, how do we count how many unpaired electrons there are? I'm kind of confused on the whole molecular theory as well. And as to why we use it.

nick_pantoja_3G

P, S, Cl can have expanded 8e-. However, Typically Cl is not a central atom as it has a high ionization energy.

nick_pantoja_3G

In the chapter homework, I would draw the Lewis diagrams with the correct number of bonds. But the positioning of the atoms are different. For example, I would attach an O to the top of a C instead of the left side (as seen in the book); would MY answer still be correct, as long as they are symmetri...

nick_pantoja_3G

Also someone had told me this cool memorization trick for SI units.
"Good Models Know How Dunkin Donuts Can Make U Not Petit
Giga, Mega, Kilo, Hecto, Deca, Deci, Centi, Milli, Micro (symbol looks like a “U”), Nano, Pico"

nick_pantoja_3G

Flashcards are always a good way to memorize things.

nick_pantoja_3G

Are there an easy ways to memorize the different conversions? I find it hard to remember the different conversions, like putting J in terms of Kg s and m. Etc.

nick_pantoja_3G

The hw question is "In the ultraviolet spectrum of atomic hydrogen, a line is observed at 102.6 nm. Determine the value of n for the initial and final energy levels of the electron during the emission of energy that leads to this spectral line." According to the textbook, they say the rydb...

nick_pantoja_3G

Would love to join, even though I'm all the way up in Hitch.

nick_pantoja_3G

I think it is always a good idea to show units throughout the problem just for you to know what the unit of measurement is/ keep track what you need in the final answer. It's always better to be safe and just use them throughout the problem. In regards to if its required, I'm not entirely sure.

CHEMISTRY COMMUNITY

Search found 25 matches

Re: Saying Thank You to Dr. Lavelle

3 different subsitutients for a newman projection

staggered and eclipsed conformations

Re: Graphs of Gibbs Free Energy vs. Energy

electrophile vs neutrophile

Order equations

Re: Redox Memorization Tips

reduction vs. oxidation

Re: Entropy moles

Entropy moles

definition of isothermic reversible expansion [ENDORSED]

Bond Enthalpies vs standard enthalpies of formation

moles of [oh-]

Re: Acidity constants [ENDORSED]

Re: Order of Filling and Removing Electrons in M.O. Diagrams

Re: Equilibrium Constant vs Reaction Quotient [ENDORSED]

countingg unpaired electrons in M.O. theory

Re: Lewis Structure Octet Rule Exceptions

Placing elements in Lewis diagram

Re: Memorization Tricks

Re: Memorization Tricks

SI Units/conversions memorization [ENDORSED]

Ch. 1.15 hw help

Re: Rieber Hall 14A Study Group (Fall 2016)

Re: Including Units in a Problem