How Can Hot Water Turn Ice to Water?

  • Thread starter Thread starter Kyoma
  • Start date Start date
  • Tags Tags
    Confusing Heat
Click For Summary

Homework Help Overview

The problem involves the thermal interaction between hot water and ice, specifically calculating the minimum mass of hot water required to completely melt a given mass of ice. The context includes concepts from thermodynamics, specifically latent heat and specific heat capacity.

Discussion Character

  • Exploratory, Conceptual clarification, Mathematical reasoning

Approaches and Questions Raised

  • The original poster attempts to apply the principle of energy conservation, questioning how the temperature of hot water decreases as it transfers heat to the ice. Other participants clarify the meaning of change in temperature and confirm the calculations related to temperature differences.

Discussion Status

The discussion is active, with participants providing clarifications on temperature changes and the requirements for melting ice. There is an exploration of the relationship between the heat lost by the hot water and the heat gained by the ice, but no consensus has been reached on the specific calculations or the final answer.

Contextual Notes

Participants are working within the constraints of specific latent heat and specific heat capacity values provided in the problem statement. There is an emphasis on ensuring all heat from the hot water is utilized to melt the ice, which raises questions about the assumptions regarding temperature changes.

Kyoma
Messages
95
Reaction score
0

Homework Statement



Question 1: Hot water at 100 degrees is added to 5 g of ice at 0 degrees. What is the minimum mass of hot water needed to melt all the ice? (Specific latent heat of fusion of ice = 336Jg-1, specific heat capacity of water is 4.2Jg-1K-1)

2. The attempt at a solution

Question 1:
mc[tex]\Delta[/tex][tex]\theta[/tex] = m(latent fusion)
m[tex]\Delta\theta[/tex] = 400
And then I have a doubt: How can the hot water's temperature decrease from 100 degrees to 0 degrees? ([tex]\Delta\theta[/tex] = 100 - 0)
 
Physics news on Phys.org
Kyoma said:
[tex]\Delta\theta[/tex]

what does this mean?
 
Change in temperature.
 
Think about it this way.
What is the starting temperature of my hot water? 100
What is the final temperature of my "hot" water? 0
What is the change in temperature? 100-0
Delta T is 100
 
The questions asks for "the minimum mass of hot water to melt ice". So all of the heat must go into the ice to melt it. The melting temperature of water/ice is 0°C.
 

Similar threads

  • · Replies 6 ·
Replies
6
Views
1K
Replies
12
Views
2K
  • · Replies 3 ·
Replies
3
Views
2K
  • · Replies 17 ·
Replies
17
Views
6K
Replies
11
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
7
Views
2K
Replies
4
Views
2K
  • · Replies 7 ·
Replies
7
Views
10K