USS

I've had 3 midterms (brain is fried), and I don't want to make the drive all over campus tomorrow. I figured there's someone on here that kinda knows what they're talking about.

It's a simple heat of combustion problem.

High-purity benzoic acid (C6H5COOH; Delta Hcomb = -3327 kJ/mol) is a combustion standard for calibrating bomb calorimeters. A 1.221-g sample burns in a calorimeter (head capacity = 1365J/degree c) that contains exactly 1.200kg of water. What temperature change is observed (in either C or K)?

Now, obviously the specific heat capacity of water is 4.184J/g*k

I guess I'm just stuck on how to set up the equation, that is all. I'm off to read about John Snow's mapping of Cholera... oh joy!!!


Colin

jaykew99

All i can say is good luck buddy.

kamilk69

that not that hard, same stuff i did in grade 12 chem, i forget it all now. but it wasnt that hard.

USS

Yeah, it's been 4 years since I took highschool chem. It's just a simple manipulation of equations, but I'm drawing a blank.

USS

God I'm a moron.

Simple as hell.

-q sample = q calorimeter

heat capacity X delta t (benzoic acid) + heat capacity X delta T (water) = (3227kj/mol X (1.221g benzoic acid / 122.118g/mol)) = 5.053E0 = delta T

God damn that feels good

0b00st0

Your missing the amount of grams per mol of benzoic acid. That would help.

USS

It's called a periodic table, look at it

0b00st0

The sad thing here is that your problem doesn't require any chemistry or physics at all. It's simple algebra.

Study up on math son :1. You're lacking in that dept if can't set up equations simply by looking at the units involved.

I mentioned that because it was a piece of info that was lacking. Whether you get it by looking at the peridoc table (pointless) or by just looking up the chemical itself is your problem.

USS

It was my confusion with specific heat that was the problem, not my ability to manipulate equations. Either way, I figured it out (which, if you would have read my post, you would have hopefully figured out). Eat a dick, ******.