September 20, 2020, 04:03:18 PM
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### Topic: Thermo Chem  (Read 122 times)

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#### paytmisop

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##### Thermo Chem
« on: September 16, 2020, 08:14:48 PM »

A sample of copper was heated to 120oC and then thrust into 200 g of water at 25.00oC.  The temperature of the mixture became 26.50oC.
1. How much heat in joules was absorbed by the water?
2. The copper sample lost how many joules?
3. What was the mass in grams of the copper sample?

#### Corribus

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##### Re: Thermo Chem
« Reply #1 on: September 16, 2020, 08:18:22 PM »
What men are poets who can speak of Jupiter if he were like a man, but if he is an immense spinning sphere of methane and ammonia must be silent?  - Richard P. Feynman

#### paytmisop

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##### Thermo Chem
« Reply #2 on: September 16, 2020, 08:32:26 PM »
Okay so, I am in a dilemma. The question is: A sample of copper was heated to 120oC and then thrust into 200 g of water at 25.00oC.  The temperature of the mixture became 26.50oC.
1. How much heat in joules was absorbed by the water? (q=1.25 kJ)
2. The copper sample lost how many joules? (Copper lost 1.25 kJ)
3. What was the mass in grams of the copper sample? (m = 34.8 g)

For my c value, I simply subtract 120 by 26.5 to get -93.5. Then I convert 200g into kg which is 0.2Kg for my m. I already know the heat capacity is 4.18 (cuz its water). Somehow I keep getting the question wrong, even though I'm simply plugging in these numbers into the Q=mc T formula. What am I doing wrong?

#### billnotgatez

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##### Re: Thermo Chem
« Reply #3 on: September 16, 2020, 10:35:59 PM »
@paytmisop
I merged your 2 posts since they deal with the same question.

#### Borek

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##### Re: Thermo Chem
« Reply #4 on: September 17, 2020, 03:06:01 AM »
For my c value, I simply subtract 120 by 26.5 to get -93.5.

That looks more like ΔT. But there are two ΔTs in the problem, and - assuming you are doing the first part of the question (a) it is not the one you should use..

Quote
Then I convert 200g into kg which is 0.2Kg for my m. I already know the heat capacity is 4.18 (cuz its water). Somehow I keep getting the question wrong, even though I'm simply plugging in these numbers into the Q=mc T formula. What am I doing wrong?

Logic looks OK, hard to tell not seeing specific details of your work.
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