Calculate the heat released when 25.0 g of steam at 100 °C condenses to a liquid at 100 °C.The specific heat of water is 1.00 cal/(g x °C);the heat of fusion is 80.0 cal/g;and the heat of vaporization is 540.0 cal/g.

Question

Quizplus · Accepted Answer

First, we need to calculate the heat released during the steam to water phase change (condensation):
q = m × ΔH_vap = 25.0 g × 540.0 cal/g = 13500.0 cal
Next, we need to calculate the heat released during the water to water phase change (cooling):
q = m × C_s × ΔT = 25.0 g × 1.00 cal/(g x °C) × (100 °C – 100 °C) = 0 cal (since there is no temperature change during phase change)
Finally, we need to calculate the heat released during the water to water phase change (freezing):
q = m × ΔH_fus = 25.0 g × 80.0 cal/g = 2000.0 cal
The total heat released is the sum of these three heats:
q_total = 13500.0 cal + 0 cal + 2000.0 cal = 15500.0 cal
Therefore, the answer is E, 1.35 x 104 cal.

Calculate the Heat Released When 25