• Support PF! Buy your school textbooks, materials and every day products via PF Here!

Energy lost in conversion of steam to ice

  • Thread starter ttk3
  • Start date
28
0
1. Homework Statement

How many J of energy must be removed when 145.0 g of steam, at a temperature of 188.0°C, is cooled and frozen into 145.0 g of ice at 0°C? Take the specific heat of steam to be 2.1 kJ/(kg·K).


2. Homework Equations

Q=m*L

3. The Attempt at a Solution

Energy = Mgas:liquid*Lvaporization + Mliquid:solid * Lfusion

.145*22.6E5 + .145*33.5E4 = 3.76E5 J
 

mgb_phys

Science Advisor
Homework Helper
7,744
11
You also need to account for the energy to cool the steam from 188C to and then cool the water from 100C to 0C.
Use Q = m*c*T
 
28
0
hm... it's still not working.

I added .145(2.1)(88) + .145*4186*100 = 60723.769 J

The total I found was 4.37E5 J.
 

mgb_phys

Science Advisor
Homework Helper
7,744
11
cool steam = 0.145 * (188-100) * 2100
condense steam = 0.145 * 2272E3
cool water = 0.145 * (100-0) * 4181
freeze water = 0.145 * 334E3

Just a small typo, the heat capcity of steam is 2.1KJ/kg = 2100 J/kg
 

Related Threads for: Energy lost in conversion of steam to ice

Replies
0
Views
2K
Replies
4
Views
18K
  • Posted
Replies
1
Views
5K
  • Posted
Replies
12
Views
4K
Replies
5
Views
1K
Replies
5
Views
14K
Replies
3
Views
2K
  • Posted
Replies
3
Views
1K

Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving
Top