# Anyone up for some chemistry help? :)

I left my class notes in our chem director’s office on Friday. I’m pretty sure the exact equation we need is in those notes, however, there is not an equation in the book that is working w/ the homework problem. Go figure. Unless, I’m remembering things wrong from lecture, and then…well…I’ll just feel rather silly.

I’ll try - what’s up?

Hehe. I ended up missing class due to an ill child, so I gained an extra day to work on it!

Suppose a catalyst lowers the activation barrier of a reaction from 125 kJ/mol to 55 kJ/mol. By what factor would you expect the reaction rate to increast at 25 celcius? (Assume that the frequency factors for the catalyzed and uncatalyzed reactions are identical.)

Initially I thought it was an arrangement of the Arrhenius equation subratcting the two equations together, but it’s just not working.

Ea = -RTln(k/A) was the equation I started with. Worked it around to where k was on the left alone and set up two equations. One for 125kJ/mol and one for 55 kJ/mol.

That did not work. lol

My very first post on OPM – I hope I’m not putting my foot in my mouth here because I’ve not even started studying! I think the answer’s 1.0286?

k2/k1 = e^[(Ea2-Ea1)/(RT)] @ T=298.15, A cancels out.

I hope that makes sense.

Answer in the book gives 10 to the 12th power.

I was canceling out A as well. But it has something to do w/ I’m not sure what lol.

oh wait…Rate. Rate does something. I need a different equation entirely.

off to rework it…tomorrow after my lab final I’m totally unprepared for w/ a screaming baby on my lap.

Wish I could help ya… good luck with it, though! (And welcome to OPM, dullhead. Thanks for the contribution )

YUCK!

Hmm, well, 1.028 ain’t too far from 10^12 methinks…

Anyway, I’ve not cracked open a textbook in 10+ yrs, saw a nice looking equation in your forum post and got all trigger happy! I wish I could help but looks like I’m not there yet…

And thanks Adam – Good to be here. I prefer OPM over other similar websites due to the cooperative atmosphere here. It’s also a huge bonus that all the OPM diaries are so inspiring. I draw hope from them.

You were right dullhead! I have no idea why I wasn’t seeing that. I sat in the professor’s office and laughed at myself as he gave me strange looks.