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Topic: did i do this correctly?  (Read 3092 times)

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Offline ding0

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did i do this correctly?
« on: November 16, 2009, 07:13:55 PM »
A 12.0 gram piece of pure gold originally at 80°C is cooled and in the process releases 72.8 Joules of heat. What is the final temperature of the gold in degrees Celsius?

My answer: 33°C

My work:
Q=mc :delta:T
 :delta:T= Q/(mc)
Q= -72.8 J
m= 12 g
c= 0.129 J/(g*K)
:delta:T= ?

Plugged it all in the equation and I get: :delta:T= Q/(mc)= -47 Kelvin
 :delta:T=TF -TI
change in T = T final minus T initial where T is Temperature
TF=  :delta:T+TI
TF= -47 K + 353 K = 306 K **80°C=353 K**
306 K = 33°C

My answer: 33°C


Correct?
« Last Edit: November 16, 2009, 07:24:14 PM by ding0 »

Offline renge ishyo

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Re: did i do this correctly?
« Reply #1 on: November 16, 2009, 07:20:19 PM »
I did it and got the same number at least.

Offline Entrigued

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Re: did i do this correctly?
« Reply #2 on: November 18, 2009, 11:34:33 AM »
A 12.0 gram piece of pure gold originally at 80°C is cooled and in the process releases 72.8 Joules of heat. What is the final temperature of the gold in degrees Celsius?

My answer: 33°C

My work:
Q=mc :delta:T
 :delta:T= Q/(mc)
Q= -72.8 J
m= 12 g
c= 0.129 J/(g*K)
:delta:T= ?

Plugged it all in the equation and I get: :delta:T= Q/(mc)= -47 Kelvin
 :delta:T=TF -TI
change in T = T final minus T initial where T is Temperature
TF=  :delta:T+TI
TF= -47 K + 353 K = 306 K **80°C=353 K**
306 K = 33°C

My answer: 33°C


Correct?

It is indeed correct. Good job, keep it up! :)

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