How much heat energy (KJ) is required to boil 2 liters of water at 25 degrees C in aluminum container (0.215 Calorie/gram *degrees C) HELP!!!
2007-12-08 16:17:49 · 2 answers · asked by anfisa03 1 in Science & Mathematics ➔ Chemistry
You have some banana and apple units so you have to be careful. Heat is needed for 3 chores:
To heat 2000 g of water from 25 to 100 deg C. This takes 2000*4.18*75 Joules
To heat the container from 25 to 100 deg C. This takes 0.215 cal *4.18 J/cal* wt of container* 75 deg C. If you don't have the weight of the container, you can't figure this out. But don't get too bent out of shape, it probably way less than either of the other two chores.
Finally, to convert the 2000 g of water at 100 deg C to vapor. If the latent heat of vaporizaton is Hv joules/gram (I don't know the exact number), this is multiplied by 2000 g.
Once you have the 3 heat terms figured out, you can multiply the result by 0.001 to get the result in kJ.
2007-12-08 17:03:25 · answer #1 · answered by cattbarf 7 · 0⤊ 0⤋
The container doesn't matter.
heat energy=m*cp* change in temp.
2 liters = 2000g
Specific heat of water is 4.184J/g C degrees
your change in temp is 75 degrees C
heat energy = 2000*4.184 * 75
heat energy= 627,600 J or 627.6 KJ
2007-12-09 01:38:51 · answer #2 · answered by Christina 2 · 0⤊ 0⤋