What is a Sphere Equation? Help with Chemistry Problem

[Math Is Hard]

OK, I'm clueless. I have this one homework problem where I am asked to represent a reaction with a "sphere equation". I have no idea what this is and I can't locate it in my book. Wasn't mentioned during lecture either.
Does anyone know what this means?

Here's the whole problem (maybe it will make sense in context):

a) write a chemical equation for the complete combustion of ethane.
b) represent this equation with Lewis structures.
c) represent this reaction with a sphere equation.

 

[Tide]

I think they are asking you to draw a picture of the reaction using spheres to represent the atoms of each molecule.

 

[Math Is Hard]

I think they are asking you to draw a picture of the reaction using spheres to represent the atoms of each molecule.

hey Tide - thanks for responding. Do you mean kinda like a ball and stick diagram?

 

[Tide]

Yes - but without the sticks!

 

[Math Is Hard]

hmm.. ok, maybe I can try to draw them like the "space-filling models".
http://academic.reed.edu/chemistry/roco/Geometry/space_filling.html
anyway, thanks for looking at the problem. I'll post again after I show her my homework.

 

[Chronos]

Use x^2 + y^2 + z^2 = c to define the boundaries of spherical surfaces.

 

[Math Is Hard]

OK, it seems all she was looking for was a "ball and stick" drawing for each molecule in the reaction, but my space filling representations were acceptable. Darn chemistry! Too much artwork!

 

[Gokul43201]

OK, I'm clueless. I have this one homework problem where I am asked to represent a reaction with a "sphere equation". I have no idea what this is and I can't locate it in my book. Wasn't mentioned during lecture either.
Does anyone know what this means?
Here's the whole problem (maybe it will make sense in context):
a) write a chemical equation for the complete combustion of ethane.
b) represent this equation with Lewis structures.
c) represent this reaction with a sphere equation.

MIH : What you want is called a Newman Diagram or Newman representation. That only tells you the conformational arrangement of atoms in a molecule (like ethane), but can not represent a reaction.

There's no such thing in chemistry as a sphere equation for a chemical reaction. At best, you can write an equation of state based on a hard-sphere interaction model, but that has nothing to do with this question.

 

[Astronuc]

Description of hard sphere equation.

http://www.math.rutgers.edu/~lebowitz/PUBLIST/jll.pub_43.pdf


It would appear that one is to represent the equation of state as:

p/\rhokT = a(\rho) + b(\rho)/kT + c(\rho)/(kt)² + . . .

or see if this looks familiar

http://www.zae-bayern.de/ectp/abstracts/maeso1.html

Have you seen the Carnahan-Starling equation yet?

This might be a question for Gokul.

 

[Math Is Hard]

ahh yes.. Newman Diagrams..
http://www.sollicitatiegesprek.nl/newman.jpg
Never heard of 'em!
umm.. before you guys get too carried away, I should tell you this is a class for NON-science majors. I am lazy as hell, and want to do the LEAST amount of chemistry possible. Here's the description:

Designed for non-science majors, this course examines the concept of the submicroscopic world of chemistry, ranging from protons to proteins in subject matter. Prerequisite: Beginning and Intermediate Algebra for College Students or two years of high school algebra.

And the book is from our friends at The American Chemical Society.
http://www.chemistry.org/portal/a/c/s/1/acsdisplay.html?DOC=education%5Ccurriculum%5Ccontext.html"

 

[Gokul43201]

ahh yes.. Newman Diagrams..
http://www.sollicitatiegesprek.nl/newman.jpg

That's the one !

Newman diagrams are very simple things with a fancy name. It's one of the first things you learn in organic chemistry.

Here's what one looks like :

http://www.chem.tamu.edu/organic/Spring2004/Review/Image382.gif

 

[Math Is Hard]

hmm.. y'know Gokul, that doesn't look quite as scary as I imagined. I was curious about it, so I found some explanations of the diagrams here:
http://www.chem.ucalgary.ca/courses/351/Carey5th/Ch03/ch3-diagrams.html
so if I understood what they said correctly, that intersection in the front (of the diagram you posted) represents one carbon atom, and it has CH₃, Br, and H attached to it. Then the circle would be another carbon atom (behind it) that the front one is bonded to, and it has CH₃ and two H atoms attached to it.
http://www.chem.tamu.edu/organic/Spring2004/Review/Image382.gif
So it's kind of like a perspective drawing?

 

[Gokul43201]

Yup. That's all it is !