## Problem 4.17

Brian_Ho_2B
Posts: 221
Joined: Fri Aug 09, 2019 12:16 am

### Problem 4.17

I'm looking at problem 4.17, where in part e, it asks for the change in enthalpy. The information given is that we have 2SO2 + O2 produces 2SO3 (all gasses) at 25 degrees C and 1.00 atm. I know that the work done is positive 40J, but I have no idea how to find change in enthalpy for this problem. Can anyone point me in the right direction?

Julie Park 1G
Posts: 100
Joined: Thu Jul 25, 2019 12:15 am

### Re: Problem 4.17

You'll want to use the standard enthalpies of formation and the coefficients of the balanced equation to find the enthalpy of the reaction.

Since the question says that 0.030mol of SO2 are consumed, you can use dimensional analysis by multiplying 0.030 mol of SO2 by the ratio of -197.78 kJ per 2 mols of SO2 to find the final value, which you can convert from kJ to J.

Brian_Ho_2B
Posts: 221
Joined: Fri Aug 09, 2019 12:16 am

### Re: Problem 4.17

Julie Park 1G wrote:You'll want to use the standard enthalpies of formation and the coefficients of the balanced equation to find the enthalpy of the reaction.

Since the question says that 0.030mol of SO2 are consumed, you can use dimensional analysis by multiplying 0.030 mol of SO2 by the ratio of -197.78 kJ per 2 mols of SO2 to find the final value, which you can convert from kJ to J.

Thank you; I couldn't find those values for those molecules in the book anywhere so I tried other ways of finding the delta H. Turns out we had to look them up online.

Return to “Reaction Enthalpies (e.g., Using Hess’s Law, Bond Enthalpies, Standard Enthalpies of Formation)”

### Who is online

Users browsing this forum: No registered users and 3 guests