HW 8.13 & Heat Absorption

Moderators: Chem_Mod, Chem_Admin

Michelle_Nguyen_3F
Posts: 40
Joined: Wed Sep 21, 2016 2:59 pm

HW 8.13 & Heat Absorption

Postby Michelle_Nguyen_3F » Wed Jan 18, 2017 5:55 pm

"In a combustion cylinder, the total internal energy changes produced from the burning of a fuel is -2573 kJ. The cooling system that surrounds the cylinder absorb 947 kJ as heat. How much work can be done by the fuel in the cylinder?"

I know to use = q + w. So = -2573 kJ and q = -947 kJ. However, why is it that the 947 kJ that is absorbed negative? Thank you!

Chem_Mod
Posts: 18898
Joined: Thu Aug 04, 2011 1:53 pm
Has upvoted: 717 times

Re: HW 8.13 & Heat Absorption

Postby Chem_Mod » Wed Jan 18, 2017 6:16 pm

The cooling system is absorbing 947 kJ of heat from the combustion cylinder, so the system is losing heat.

Jata_Kavya_3A
Posts: 22
Joined: Wed Sep 21, 2016 2:57 pm

Re: HW 8.13 & Heat Absorption

Postby Jata_Kavya_3A » Thu Jan 19, 2017 1:32 pm

if the system is losing heat, then the internal energy of the system decreases because q is negative. Vice versa, if the system absorbs or gains heat.


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 4 guests