A 5.00 kg block of ice at –25 oC is converted to steam at 125 oC. How much energy (in kilojoules) is expended in this process? The following data are provided:

Question

a. Specific heat of ice = 2.092 J/g oC
b. Latent heat of fusion = 334.72 J/g
c. Specific heat of water = 4.184 J/g oC
d. Latent heat of vaporization = 2299.36 J/g
e. Specific heat of steam = 2.008 J/g oC

Answer 1

This isn't complicated but it's a 4 or 5 step process. Here is how you do any problem like this. There are really only two formulas you need (3 actually but two are almost the same).

q = heat required to move T from any T to any other T IN THE SAME PHASE is
q = mass x specific heat in that phase x (Tfinal-Tinitial)

For example, for ice at -25 to ice at zero (starts at ice and continues in same phase as ice.

When you get to a phase change (solid to liquid as in ice melting at the melting point of ice) or (liquid to vapor as in liquid water to steam at boiling point of H2O) it is
for m.p., q = mass ice x heat fusion

for b.p., q = mass water x heat vaporization.

Then add the q for each phase to get total q.
Post your work if you get stuck.

Answer 2

I am so confused. I do not get it at all.

Answer 3

What's the problem?
You go from -25 C to zero C(the melting point) with equation 1 (single phase, ice to start and ice to end)

You melt the ice at 0C using equation 2 (heat fusion one) (this is a phase change from solid to liquid)

You go from liquid water at zero C to 100 C with equation 1. (single phase water to begin and water to end)

You boil the water at 100 C to steam at 100 using equation 3 (the heat vaporization one). (another phase change from liquid to vapor)

You go from steam at 100 to steam at 125 C using equation 1 (single phase of steam to start and steam to end).

Then add all of the q values for each step together for the total.

For the first part for ice at -25 to ice at zero C you have
(mass ice x specific heat ice x (Tfinal-Tinitial).
You have mass ice in grams, specific heat ice listed in your post, Tf is 0 and Ti is -25. Calculate q1 for that part of the problem and go to step 2; i.e., the melting of ice at zero to liquid water at zero C.