Iced tea and water problem

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Nicole Anisgard Parra 2H
Posts: 39
Joined: Sat Jul 22, 2017 2:01 am

Iced tea and water problem

Postby Nicole Anisgard Parra 2H » Tue Feb 13, 2018 6:53 pm

"In order to make iced-tea, a 30.0 g ice cube at 0 degrees c is added to 250 ml of tea at 20.0 degrees c. What is the final temperature of the iced-tea once it has reached thermal equilibrium? Assume no heat is transferred to and from the surroundings. The density of water (and iced tea) is 2.00 g/ml over the range of 0-25 degrees c."
I know for this question, we must first account for the phase change of the ice by finding the moles of ice and then multiplying it by the enthalpy of fusion for water, then adding it to mCspΔT for the ice and setting it equal to -mCspΔT for the liquid water, to find the final temperature of the iced tea. My question is, on the ice side of the equation, do we use the specific heat capacity of ice rather than that of water? I used the specific heat capacity of liquid water on both sides (4.184 g/C/g), but it supposedly isn't correct. Why is that? Once the ice is melted during the phase change, isn't it above 0 degrees C, when we would then use the specific heat capacity of liquid water?
Thanks!

Andy Nguyen 1A
Posts: 56
Joined: Thu Jul 27, 2017 2:00 am

Re: Iced tea and water problem

Postby Andy Nguyen 1A » Tue Feb 13, 2018 8:39 pm

I think that what you did is right since the ice melts so it becomes liquid water, so you have to use the specific heat capacity of water at a liquid. Was the enthalpy of vaporization in kJ/mol because that could effect how you convert the units. Hope this helps!

Sarah Wax 1G
Posts: 29
Joined: Sat Jul 22, 2017 2:00 am

Re: Iced tea and water problem

Postby Sarah Wax 1G » Sat Mar 17, 2018 9:43 pm

I also was conflicted on this question. I'm assuming since the ice cube starts as a solid when the reaction first goes, you need to use H of ice, and then once it's heated, use H of water.


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