How much energy does it take to heat a block of ice

AI Thread Summary
To calculate the energy required to heat a 35 g ice cube from -15°C to steam at 117°C, the specific heats and phase changes must be considered. The calculations involve raising the ice temperature to 0°C, melting it to water, heating the water to 100°C, vaporizing it to steam, and finally raising the steam temperature to 117°C. The initial calculation of 114,734 J was incorrect due to an oversight in the temperature increase of the steam, which only needs to rise 17°C instead of 100°C. Correcting this error will yield the accurate total energy required. Accurate calculations are crucial in thermodynamic problems to ensure correct results.
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Homework Statement


How much energy is required to change a 35 g ice cube from ice at −15 C to steam at 117 C?
The specific heat of ice is 2090 J/kg * C, the specific heat of water is 4186 J/kg * C, the specific heat of stream is 2010 J/kg * C, the heat of fusion is 3.33 × 10^5 J/kg, and the heat of vaporization is 2.26 × 10^6 J/kg.
Answer in units of J.


Homework Equations



Q=m*L
Q=m*c*\DeltaT

The Attempt at a Solution


35g*15C*2090J/kg*C - heat to raise ice's temp. to freezing
+ 3.33 * 10^5 J/kg *35g - heat to melt ice into water
+ 100C *4186J/kg*C *35g - heat to raise water temperature to boiling
+ 2.26*10^6 J/kg* 35g - heat to boil water into vapor
+ 2010 J/kg*C *117C *35g - heat to make vapor rise to 117 C
=114734 J

I tried this answer and the program says it's incorrect, what am I doing wrong?
 
Physics news on Phys.org
The steam only has to rise 17C in temperature from 100C to 117C.
 
Thanks for your help... I completely missed that, I guess that's what I get for trying to do physics late at night. :)
 
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