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

In summary, to change a 35 g ice cube from ice at -15 C to steam at 117 C, a total of 114734 J of energy is required. This includes 35 g * 15 C * 2090 J/kg * C for heating the ice to freezing, 3.33 * 10^5 J/kg * 35g for melting the ice into water, 100 C * 4186 J/kg * C * 35g for heating the water to boiling, and 2.26 * 10^6 J/kg * 35g for boiling the water into steam. However, the steam only needs to rise 17 C in temperature from 100 C to 117 C,
  • #1
Runaway
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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*[tex]\Delta[/tex]T

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?
 
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  • #2
The steam only has to rise 17C in temperature from 100C to 117C.
 
  • #3
Thanks for your help... I completely missed that, I guess that's what I get for trying to do physics late at night. :)
 

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

The amount of energy required to heat a block of ice depends on the mass of the ice, the starting temperature of the ice, and the desired final temperature. It can be calculated using the specific heat capacity of ice and the formula Q = mcΔT, where Q is the energy in Joules, m is the mass of the ice in kilograms, c is the specific heat capacity of ice (2.09 J/g°C), and ΔT is the change in temperature in Celsius.

2. Can the energy needed to heat a block of ice be calculated using the specific heat capacity of water?

No, the specific heat capacity of water (4.18 J/g°C) cannot be used to calculate the energy needed to heat a block of ice. This is because the specific heat capacity of ice is different from that of water, and it takes more energy to heat ice than water due to its phase change from solid to liquid.

3. What is the specific heat capacity of ice?

The specific heat capacity of ice is 2.09 J/g°C. This means that it takes 2.09 Joules of energy to raise the temperature of 1 gram of ice by 1 degree Celsius.

4. Does the shape of the block of ice affect the amount of energy needed to heat it?

Yes, the shape of the block of ice can affect the amount of energy needed to heat it. This is because the surface area of the ice can affect the rate of heat transfer. A larger surface area will allow for faster heat transfer and therefore require more energy to heat the ice.

5. How does the starting temperature of the ice affect the amount of energy needed to heat it?

The starting temperature of the ice affects the amount of energy needed to heat it because it determines the initial heat energy of the ice. The closer the starting temperature is to the final desired temperature, the less energy will be required to heat the ice to that point.

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