Rocks R Tasty

Initially, I thought it might have been a satellite or a planet, for there was no "twinkling" effect visible to my eyes, until it suddenly did twinkle ever so slightly - perhaps it is a very bright star? I saw it immediately above my head circa 6:25 am approximately 49 to 54 degrees north. The sky was already becoming lighter, but the sun's rays were not fully visible. How was it possible to see this star, and which star is it? It was not moving, either, so it could not have been a meteor, could it have?

"The compound squaric acid (

http://upload.wikimedia.org/wikipedia/commons/b/bd... ) is a diprotic acid, with both protons being more acidic than acetic acid. In the dianion obtained after the loss of both protons, all of the carbon-carbon bonds are the same length as well as all the carbon-oxygen bonds. Provide a resonance explanation for these observations."

I'm thoroughly confused about how to explain a concept with resonance...

"At 25ºC the enthalpy change, (delta)Hº, for the ionization of trichloroacetic acid is +6.3 kJ/mol and the entropy change, (delta)Sº, is +0.0084 kJ/mol*K. What is the pKa of trichloroacetic acid?"

The formula/s required for solving this would be appreciated. Thanks!

So it's the beginning of Spring Break, and I figured I'd have some fun with Organic Chemistry homework problems, but this is difficult. I'm not sure how to do these (might be a failure in the section on resonance structures for First Semester)...Just Number 24. If you could provide me with additional sources of help with resonance structures as well as show me how to answer, I'll do my best to give you all five stars and vote as best in a timely fashion. ^.^ Thanks!

http://img148.imageshack.us/img148/2424/orgo.jpg

I have a problem I'm working on, and do not know where to begin - neither the teacher's notes, the classroom lecture notes I wrote, nor the textbook appear to be showing me (I could be in need of looking earlier in the book, as this could be a simple straightforward 1st semester reaction, however, I've become so lost with regards to where to find the answer).

We begin with 3-methyl-5-hexen-2-ol, treat it with H3PO4 and heat, and we create 4-methyl-1,3-hexadiene and H3O(+). I'm lost as to how to show this mechanism fully with the arrows, because I can't remember what H3PO4 and heat do to an alcohol.

Any help is appreciated, and I'm using Solomon's 10th edition, in case you can refer me to a chapter in the textbook that covers this (in case I missed it, which I must have!) Thanks in advance.

In Solomon's 10th Edition Organic Chemistry textbook, there is a question causing difficulty...

It's Chapter 11, Problem 30d.

They ask us to show how we might prepare 2-bromobutane from 1-Butyne.

I'll draw a picture, scan it, and add it later (hopefully, if I can), but in the mean time, my attempts have been to use Br2 to break open the alkyne bond and form the Bromonium ion, but then the Br- comes in for an SN2-like anti-addition (right?) and now we have a di-bromo-alkene, and I do not know what to do. Should I have started with using H-Br instead of Br-Br? And can anybody hint at the next step (if you're familiar with the section of the book that covers these, or the name of the reaction/s needed to solve the problem, it would be greatly appreciated for self-study purposes, as I've looked through a lot of the books -Chapters 6, 7, 8, 9, and 11, and am not able to find the help I think I need).

Thanks in advance to anybody who attempts to help me! :)

So there's an enol, and it's reacted with Sulfuric Acid and Water, and it forms this weird 2,2-methylethyl-1-oxacyclohexane molecule, and I am asked to show a step-by-step mechanism for it, including all intermediates, charges, and curved arrows. Please see the picture: http://img713.imageshack.us/i/orgoe.jpg/

I've scoured the whole of Chapter 11 in the 10th Edition of Solomon's Organic Chemistry, but I could not find it explained anywhere. *cries*

The Question reads: Show how you would make the following product from the indicated starting material, plus any other reagents. (it does not seem to mention anything about pushing arrows or mechanisms, so do we just write down the results for each step?)

b) Cycloheptanol ----(?)-----> Cyclohepta-1,3-diene

It seems pretty clear to me that we need to utilize the dehydration of alcohols for the first step (H3PO4 and heat removes OH and H to create cyclohepta-1-ene), but I can't for the life of me, figure out what the second step is to create the 3-diene part (either my eyes cannot find it in the book, it's not in the chapter from which this problem came, or it has a name unfamiliar to me which I can hopefully look up in the index, should some knowing answerer gracefully hint me toward the name of the necessary reaction).

Thanks for the help!

From my understanding, UV radiation will provide a photon of light energy to the outer electrons, they absorb this energy, become excited, and are "promoted" to the next higher-energy outer shell. Is this a correct understanding? Could anybody perhaps provide me with more detail?

Then my main question, how does this differ from the photoelectric effect?

Thx in advance for your time and trouble. Need by 4:00 pm EDT. =)

My teacher will use two terms intermittently, for example, if my teacher is talking about why dogs and cats hate each other, my teacher will say:

"dogs hate cats because XYZ and cats hate dogs because ABC"

and then within a few seconds, my teacher will 'recap' what was just said, but then confuse the order, but saying, "So Cats hate Dogs because XYZ, and therefore Dogs hate Cats because ABC."

What in the world is wrong with my teacher?

(Please no "Your teacher is only human" answers - Thx!)

For those who are familiar with the Mastering Physics homework,

I would like some help with how to enter my answer, to ensure I

receive 100% credit for it. It requests:

Express the ratio I(sub2) / I(sub0) numerically.

So, supposing my answer were "5/8" would I enter in the fraction "5/8" or

would I give the answer as a number after dividing 5 by 8, as "0.625"?

Thank you for your help!!

So there I was, petting my mother-in-law's kitten, and out of nowhere, the little whack job thought it would be fun to make a toy out of my eyeball, via clawing at it.

There are now two beautiful red lines inside the eyeball that lead toward the suspected area of attack (i.e. where the claw/nail went in).

Should I give a hoot, or will my eye be fine in a few minutes?

Need help with solving series problems, but do not know how to effectively write the symbols above and below Sigma, instead I get a big mess like this:

Σ∞n=1nxn-1 | x | < 1

How are other Math questions relating to Series and Sigma usually typed in Yahoo! Answers ?

How do we solve for this? I am completely lost. T_T

Find a power series representation for the function and determine its radius of convergence.

f(x) = (x^2) / [(1 - 2x)^2]

Which process do we use, and can you please show the work (this is very new information for me, and still grasping concepts)?

Use binomial series to expand a function as a power series, then state the radius of convergence.

(x^2) / sq-rt(2+x)

Find the solution of the differential equation that satisfies the given initial condition

dL/dt = kL^2lnt, L(1) = -1

Easy 10 points for first to answer with as much detail as possible. Assume you are attempting to explain this to a 15 year old or younger. Like, what is it, when and how is it used, for what purpose, why would we use it? Etc, etc. @_@

Find the orthogonal trajectories of the family of curves.

y = x / (1 kx)

Also, what is meant by "Use a graphing device to draw several members of each family on a common screen." ?

What should we do if we are asked to solve the differential equation

dz/dt e^(t z) = 0

A function y(t) satisfies the differential equation

dy/dt = y^4 - 6y^3 5y^2

a) What are the constant solutions of the equation?

b) For what values of y is y increasing?

c) For what values of y is y decreasing?

Worked on this already, and I came up with two ways to approach it. Not sure if either way is correct method, nor if I got the right answer.

How would you Calculus buffs do this?