Final temperature after pouring soda into glass with ice....

Click For Summary

Homework Help Overview

The problem involves a thermal interaction between soda and ice, specifically calculating the final temperature of the mixture after pouring soda at 13 degrees Celsius into ice at -19.5 degrees Celsius. The discussion includes specific heats and latent heat of fusion relevant to the phase change of ice.

Discussion Character

  • Exploratory, Assumption checking, Problem interpretation

Approaches and Questions Raised

  • Participants discuss converting the mass of soda from ounces to kilograms and setting up energy equations to find the final temperature. There is uncertainty about incorporating the latent heat of fusion into the calculations.

Discussion Status

Some participants have attempted calculations and received feedback indicating that the phase change of ice at 0 degrees Celsius must be considered. There is an ongoing exploration of whether all the ice will melt and how the system reaches thermal equilibrium.

Contextual Notes

Participants note that the problem may imply not all ice will melt, which raises questions about the final temperature of the system and the stages of energy transfer involved.

NY152
Messages
24
Reaction score
0

Homework Statement


Soda from a ms=12 oz can at temperature Ts=13 degrees C is poured in its entirety into a glass containing a mass mI=0.16kg amount of ice at temperature TI=-19.5 degrees C. Assume that ice and water have the following specfic heats c1=2090 J/(kg*C) and cs= 4186 J/(kg*C), and latent heat of fusion of ice is Lf=334 kj/kg.

a) In degrees celsius, what is the final temperature Tfinal of the mixture?
b) Write an expression for how much of the ice mmelted has melted?
c) In kilograms, how much of the ice mmelted has melted?

Homework Equations


Q= m*c*deltaT

The Attempt at a Solution


So I think you start by converting the 12 oz can to kg to get the mass at that particular temperature. Then would you set two separate Q equations equal to one another to solve for Tf? So Q= ms*cs*(Tf-13) and Q= mI*cI*(Tf-(-19.5)) and set these equal to each other, but then how does the latent heat of fusion of ice play into the calculation?
 
Physics news on Phys.org
Ok
NY152 said:

Homework Statement


Soda from a ms=12 oz can at temperature Ts=13 degrees C is poured in its entirety into a glass containing a mass mI=0.16kg amount of ice at temperature TI=-19.5 degrees C. Assume that ice and water have the following specfic heats c1=2090 J/(kg*C) and cs= 4186 J/(kg*C), and latent heat of fusion of ice is Lf=334 kj/kg.

a) In degrees celsius, what is the final temperature Tfinal of the mixture?
b) Write an expression for how much of the ice mmelted has melted?
c) In kilograms, how much of the ice mmelted has melted?

Homework Equations


Q= m*c*deltaT

The Attempt at a Solution


So I think you start by converting the 12 oz can to kg to get the mass at that particular temperature. Then would you set two separate Q equations equal to one another to solve for Tf? So Q= ms*cs*(Tf-13) and Q= mI*cI*(Tf-(-19.5)) and set these equal to each other, but then how does the latent heat of fusion of ice play into the calculation?
O
NY152 said:

Homework Statement


Soda from a ms=12 oz can at temperature Ts=13 degrees C is poured in its entirety into a glass containing a mass mI=0.16kg amount of ice at temperature TI=-19.5 degrees C. Assume that ice and water have the following specfic heats c1=2090 J/(kg*C) and cs= 4186 J/(kg*C), and latent heat of fusion of ice is Lf=334 kj/kg.

a) In degrees celsius, what is the final temperature Tfinal of the mixture?
b) Write an expression for how much of the ice mmelted has melted?
c) In kilograms, how much of the ice mmelted has melted?

Homework Equations


Q= m*c*deltaT

The Attempt at a Solution


So I think you start by converting the 12 oz can to kg to get the mass at that particular temperature. Then would you set two separate Q equations equal to one another to solve for Tf? So Q= ms*cs*(Tf-13) and Q= mI*cI*(Tf-(-19.5)) and set these equal to each other, but then how does the latent heat of fusion of ice play into the calculation?
Okay so I did: 4186*0.340194*(13-T) = 2090*0.16*(T+19.5)
and found Tf=6.82 and the system says this is incorrect but the hint says "You may have forgotten that ice experiences phase change at 0 degrees celsius. Take into account the latent heat.
As stated before, I'm not sure how to incorporate this into my solution.
 
I haven't gone through the numbers, but because of the wording of the question, I suspect this is what is happening in this problem.
The liquid gets added to the ice. The liquid warms up all of the ice to its melting point. Then the liquid melts all of the ice into a liquid. Then those two liquids reach some equilibrium temperature. Now it could be the case that the liquid does not have enough energy to do all of that. But that should come out in the numbers. So yes, you have to remember that the ice changes phase at 0C and requires energy from the warm(er) liquid to do that. And the amount of energy required to warm up 1 kg of ice 1 degree C is not the same amount of energy required to warm up 1 kg of water 1 degree C, which is not the same energy required to melt 1 kg of ice.

Edit: I defer to @Chestermiller. He is right (and I was wrong) that the problem statement seems to imply that not all of the ice is melted. I guess it would help if I read the whole problem carefully. :(
 
Last edited:
The problem statement (and your calculation) seems to imply that not all the ice will have melted when the system has reached thermal equilibrium. If that is the case, what is the final temperature of the system?
 
Any more input about this problem? I still can't seem to get the right answer
 
NY152 said:
Any more input about this problem? I still can't seem to get the right answer
Things will happen in stages, and one simple, if laborious, approach is to model those.
1. Ice warms and liquid cools until one of them reaches 0C.
2. If the water reaches 0C first, it will start to freeze, giving out latent heat.
2.1 If all the water freezes and the original ice is still less than 0C, the two will balance out at some temperature below freezing.
2.2 If the ice reaches 0C before all the water freezes you are done.
3. If the ice reaches 0C first then it will start to melt,
etc.
 

Similar threads

Replies
12
Views
1K
  • · Replies 3 ·
Replies
3
Views
2K
Replies
7
Views
2K
  • · Replies 11 ·
Replies
11
Views
5K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 17 ·
Replies
17
Views
6K
  • · Replies 8 ·
Replies
8
Views
3K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
6
Views
1K
  • · Replies 1 ·
Replies
1
Views
2K