Another HELP problem: Steam to Ice

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The discussion revolves around calculating the energy required to cool and freeze 127.0 g of steam at 153.0°C into ice at 0°C. The participant initially calculated the energy using the specific heat of steam, heat of vaporization, and specific heat of water, but arrived at an incorrect total energy value. Key feedback highlighted the importance of using correct constants, particularly the heat of vaporization, which significantly impacts the calculation. Additionally, there were reminders to carefully track units throughout the calculations to avoid errors. The participant expressed frustration over consistent unit mistakes and sought clarification on their approach.
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Another URGENT HELP problem: Steam to Ice

Homework Statement



How many J of energy must be removed when 127.0 g of steam, at a temperature of 153.0°C, is cooled and frozen into 127.0 g of ice at 0°C? Take the specific heat of steam to be 2.1 kJ/(kg·K).

Homework Equations


Q1 = mc(delta T) <---- c= heat capacity of steam
Q2 = mLv
Q3 = mc(deltaT)<---- c=heat capacity of water
Q4 = mLf


The Attempt at a Solution



first I converted grams to kilograms and got .127kg for the mass then I follwed through with my equations
Q1 = (.127)(2100)(153-100)= 1.4135E4
Q2 = (.127)(2259.36)= 2.869E2
Q3 = (.127)(4186)(100-0)= 5.316E4
Q4 = 4.241E4

I added these up and got a total Q of 1.10E5, what am I doing wrong?
 
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he had a different problem (that is to say a different problem regarding the same problem) than me, I just need to know if I'm doing it right and when went wrong.
 
You have the constants wrong.
specifically the heat of vapourisation - the water/steam change should be the largest energy.
Just put you hand over a kettle to find out!
 
Last edited:
Q2 = (.127)(2259.36)= 2.869E2

Please check units!

I strongly recommend writing units with values, so that one properly accounts for orders of magnitude.
 
I seriously don't know how I keep messing up my units, but thanks again.
 

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