Question

using the following graph, identify the value of ( h_{vap} ) at point b. assume the substance is water

a 2200 j/g
b -2200 j/g
c -334 j/g
d 334 j/g

Explanation:

Step1: Recall the concept of \(H_{vap}\)

\(H_{vap}\) (heat of vaporization) is the heat absorbed when a substance changes from liquid to gas. When heat is removed (as in this case), the sign is negative. For water, the heat of vaporization is \(2200\ J/g\). But since heat is removed (condensation), the value is \(- 2200\ J/g\).

Step2: Analyze the graph

Point B on the graph represents the condensation process (gas to liquid as heat is removed). The heat of vaporization when heat is removed (condensation) has the same magnitude as heat of vaporization (vaporization) but opposite sign.

Answer:

B. -2200 J/g