The answer is H—F. Fluorine is the most electronegative of the four halogens (and, in fact, of all the elements), so it does the best job of gathering the shared electrons to itself. Therefore, the bond with F is the most polar
Explanation:
It is given that the energy change is -162 kJ and work done is -194 kJ. As we know that formula for change in enthalpy is as follows.
dH = dE + W
where, dH = change in enthalpy
dE = change in energy
W = work done
Therefore, the change in enthalpy will be as follows.
dH = dE + W
= -162 kJ + (-194 kJ)
= -356 kJ
As the negative sign indicates heat is being released. Therefore, the reaction is exothermic in nature.
Thus, we can conclude that the change in energy of the gas mixture during the reaction is -356 kJ.
The vapor molecules have greater KE than the liquid ones have. That"s how they break free of the liquid and waft away.