Calculate the amount of energy in the form of heat that is produced when a volume of 3.56 L of SO2(g) is converted to 3.56 L of SO3(g) according to this process at a constant pressure and temperature of 1.00 bar and 25.0 °C. Assume ideal gas behavior.

Answer 1

2SO2 + O2 ==> 2SO3
Convert 3.56L to mols = n. Then
dHrxn = (n*dH SO3) - (n*dH SO2)
Find dHf SO3 and dHf SO2 in tables in your text or notes.

Answer 2

Dr. Bob,

I don't think this is the answer. It's close, but I think there is another step.

Could you elaborate on your answer to make it more clear?

Answer 3

Actually I solved it - and just to clarify what Dr. bob was doing:

dHrxn = (n*dH SO3) - (n*dH SO2) where n is equal to 2 based on the stoichiometric equation 2SO2 + O2 ==> 2SO3

Indeed, Find dHf SO3 and dHf SO2 in tables in your text or notes.

Then, the number of moles of SO3(g) produced is determined from the ideal gas law.

So Convert 3.56L to mols = n using PV=nRT or n=PV/RT and use the constant R = 0.08315 in L*bar/mol/k

The chemical equation as given represents the production of two moles of SO3(g), so the energy as heat that evolved is

dH = (mols of SO3 calculated just before) x (dHrxn / 2 mol SO3)

Answer 4

dr bob is not actually dr bob.. people r using his names to give out incorrect answers.