HW 8.13 & Heat Absorption

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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!

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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.

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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.

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