Question

Regarding the vaporization of water, which of the following is true? A. A great deal of heat must be lost by water to form hydrogen bonds and allow molecules to move farther apart. B. A great deal of heat must be absorbed by water to break hydrogen bonds and allow molecules to move farther apart. C. Vaporization of water is an exothermic process. D. Water must lose a great deal of heat before it will vaporize.

Answer 1

B. A great deal of heat must be absorbed by water to break hydrogen bonds and allow molecules to move farther apart.

Answer 2

Answer: B. A great deal of heat must be absorbed by water to break hydrogen bonds and allow molecules to move farther apart.

Explanation:

Vaporization is a physical process where liquid state changes to gaseous state.

$H_2O(l)\rightarrow H_2O(g)$

Water molecules are bonded by strong hydrogen bonding between the hydrogen atom and the electronegative oxygen atom. Thus water molecules present on the surface are strongly attracted by the molecules present below the surface.

Thus as liquid state has to be changed to gaseous state, the heat must be supplied and the reaction will be endothermic.The heat is used to break the inter molecular forces or the hydrogen bonds present in water to convert them to randomly moving gaseous state.