Heat Equation

Question

How much heat energy is required to completely change 25 grams of ice at 0 degree Celsius to water and raise the temperature to body temperature (37 degree Celsius)?

Answer 1

Step 1

Basis:

M= 25 grams of Ice

T _initial= 0 degrees C 

T _final= 37 degrees C

 

Useful Information

1 calorie raises 1-gram water 1 degree Celsius.

 

 

Step 2

We have to add the latent heat required to melt the ice at 0 degrees.

q = m·ΔHf

where
q = heat energy
m = mass

 

Useful Information :ΔHf = heat of fusion =For water at 0 °C = 80 (79.7) calories per gram

 

q = m·ΔHf

q = (25 grams) x (80 cal per gram) = 2000 calories

 

Step 3

Raise Temp 37 degrees

 

q=mC(T final -T initial)

q = (25 grams) x (1 calorie/  gram-degree C) x ( 37 degrees C) = 925 cal

 

 

Step 4 Add both

q1 + q2= 2000 + 925 = 2925 cal

 

I hope this helps!

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