Question

how much heat is needed to change 20g of ice at negative 10 degrees c to water vapor at 200 degrees c

Answer 1

add the following energyies:
heat to heat ice at -10 to 0
heat to melt 20 g ice at 0C
Heat to heat water from 0C to 100C
heat to vaporize 20gwater at 100C.
heat to heat steam from 100C to 200C