Question
If a reaction involves only solids and liquids which of the following is true ?
A.
$$\Delta H < \Delta E$$
B.
$$\Delta H = \Delta E$$
C.
$$\Delta H > \Delta E$$
D.
$$\Delta H = \Delta E + \Delta nRT$$
Answer :
$$\Delta H = \Delta E$$
Solution :
$$\Delta H = \Delta E + P\Delta V,$$ for solid and liquid, $$\Delta V = 0$$
or $$\Delta H = \Delta E + \Delta nRT,$$ for solids and liquids $$\Delta n = 0$$