How much energy is needed to melt 15 grams of ice to water at #0^.C# ?
1 Answer
In Physics, when talking about energy in thermodynamics, we talk about heat.
Heat can be defined with the letter Q.
Where:
Specific heat is defined as the amount of heat that is needed to raise a 1kg mass by 1ºC/1K. Units
Liquid water has a very high Specific Heat Capacity. It is about 4180
To solve your problem, we will have to introduce a new concept, phase change . This happens when a substance goes through a change in state, in other words, it changes from liquid to solid , liquid to gas or gas to solid.
In your case, we are melting ice, which means the phase change will go from solid to liquid.
To calculate this you need a new concept, Specific Latent Heat (denoted with the letter L), which is the amount of heat that has to be supplied to a mass to change its phase. This can be calculated by:
To solve your problem, we will have to break it into parts:
- Heat needed to melt ice at 15ºC to 0ºC (still in solid state)
- Heat needed to melt solid ice at 0ºC to 0ºC liquid.
Before we start:
- Specific Heat of Ice (C)= 2108 J/(kg*ºC)
- Latent Heat of Ice (L) = 333*10^3 J/kg
Hence:
This means that to melt a 0.015kg ice cube to water at 0ºC you will need 4520.7 J of heat.