Answer :
Answer:
The amount of heat required to change 25 grams of water into steam is 50,000 joules or 11,950 calories.
Explanation:
Heat of vaporization of water = 2000J/g = 478 cal/g
You can solve this problem using either joules or calories for heat.
Part I
Use the formula q = m·ΔHv
where
q = heat energy
m = mass
ΔHv = heat of vaporization
q = (25 g)x(2000J/g)
q = 50,000 J
Part II
q = m·ΔHf
q = (25 g)x( 478 cal/g)
q = 11,950 cal
Answer
The amount of heat required to change 25 grams of water into steam is 50,000 joules or 11,950 calories.