Question

How much energy is needed to melt 250 grams of ice at 0 C?

Answer 1

You need to quote the `"latent heat of fusion of water...."`

Explanation:

And you will get a value in `J*g^-1`...and then you can assess the energy required for the transition....

`H_2O(s) stackrel(Delta, 0""^@C)rarrH_2O(l)`

Both the ice and the water are assumed to be at `0` `""^@C`...of course, if different temperatures are specified you will need the heat capacities of ice, and of liquid water...

Answer 2

`Q=83.5kJ`

Explanation:

To answer to this question, you need the equation:

`Q=L_"ice"xxm`

`Q` is the amount of heat needed to melt the ice, `L_"ice"` is the Latent Heat of melting for ice, and `m` is the given mass of ice. Various tables of latent heats give us:

`L_(ice)=3.34 · 10^5 J/(kg)`

`m=250g=0.25kg`.

So:

`Q=(3.34 · 10^5 J/(kg)) xx (0.25 " kg")=83,500J=83.5kJ`