Caculate the heat realeased as a 25.0 g gas sample condenses if the heat vaporation is 2000 j/g

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.