Posted by Tom on .
How many joules ar required to heat a frozen can of juice (360 grams) from -5 degrees C (the temp of an overcooled refrigerator) to 110 degrees C (the highest practical temp within a microwave oven)?
q1 to raise T from -5 to zero C (I assume most of this is water).
q1 = mass x specific heat x delta T.
q2 = heat to convert solid at zero C to liquid at zero C.
q2 = mass x heat fusion
q3 = heat to raise T from zero C to 100 C.
q3 = mass x specific heat x delta T.
q4 = heat to convert liquid phase at 100 C to vapor phase at 100 C.
q4 = mass x heat vaporization.
q5 = heat to raise T from 100 C for vapor to 110 C for vapor.
q5 = mass x specific heat x delta T.
total q = sum of q1 + q2 + q3 + Q4 + q5