Sphere equation?

1. Oct 24, 2005

Math Is Hard

Staff Emeritus
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.

2. Oct 24, 2005

Tide

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

3. Oct 24, 2005

Math Is Hard

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

4. Oct 24, 2005

Tide

Yes - but without the sticks!

5. Oct 24, 2005

Math Is Hard

Staff Emeritus
6. Oct 25, 2005

Chronos

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

7. Oct 25, 2005

Math Is Hard

Staff Emeritus
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!

8. Oct 25, 2005

Gokul43201

Staff Emeritus
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.

Last edited: Oct 25, 2005
9. Oct 25, 2005

Staff: Mentor

10. Oct 25, 2005

Math Is Hard

Staff Emeritus
ahh yes.. Newman Diagrams..

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:
And the book is from our friends at The American Chemical Society.
Chemistry in Context.

11. Oct 25, 2005

Gokul43201

Staff Emeritus
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 :

12. Oct 25, 2005

Math Is Hard

Staff Emeritus
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.

So it's kind of like a perspective drawing?

13. Oct 25, 2005

Gokul43201

Staff Emeritus
Yup. That's all it is !