question_answer

Water standing in the open at \[{{32}^{o}}C\]evaporates because of the escape of some of the surface mole cuels. The heat of vaporisation (540 cal/g) is approximately equal to \[\varepsilon \] n, where \[\varepsilon \] is the average energy of the escaping molecules and n is the number of molecules per gram. The value of \[\varepsilon \] is close to

A)  \[1.62\times {{10}^{-20}}J\]                       

B)  \[4.23\times {{10}^{-20}}J\]

C)  \[6.75\times {{10}^{-20}}J\]                       

D)  \[8.31\times {{10}^{-20}}J\]