# Phase change

1. May 9, 2007

### Weave

1. The problem statement, all variables and given/known data
Ok this one is easy I just want to make sure:
A metal of mass $$M$$ is in a smelter at temperature $$T_{o}$$.
How much heat does it take to melt the metal. Given: heat capacity, melting point $$T_{m}$$

2. Relevant equations
$$Q=Mc\Delta T$$

3. The attempt at a solution
So it would be simply
$$Q=Mc(T_{m}-T_{o})$$
Right?

2. May 9, 2007

### Hootenanny

Staff Emeritus
That's just the energy required to heat the metal up to the melting point, what about the actual phase change (i.e. latent heat)?

3. May 9, 2007

### Weave

so $$\frac{Q}{M}=L$$ Q being the previous answer from $$Q=Mc\Delta T$$

4. May 9, 2007

### DAKONG

it should be $$Q=Mc\Delta T + ML$$ if you melt solid to liquid

$$Q=Mc\Delta T$$ (unchange state)
$$Q=ML$$ (change state)

5. May 9, 2007

### Weave

So I am incorrect?

6. May 9, 2007

### Hootenanny

Staff Emeritus
Q isn't necessarily that from the previous answer.

7. May 9, 2007

### Weave

so..what I am I looking for?

8. May 9, 2007

### Hootenanny

Staff Emeritus
I'd be tempted to say that the question isn't answerable unless your given L; but I'm willing to learn...