Approximately how many Btus does it take to change one pound of 212 degree water into one pound of 212 degree steam?
A) 16
B) 144
C) 180
D) 970

Question

Quizplus · Accepted Answer

It takes 970 Btus to change one pound of 212 degree water into one pound of 212 degree steam. This is because during the phase change from liquid to gas (boiling), the energy is used to overcome the intermolecular forces holding the water molecules together, rather than raising the temperature of the water. This requires a large amount of energy, hence the high number of Btus required.

Approximately How Many Btus Does It Take to Change One