0. A liquid solution of LiCl in water at 25°C contains 1 mol of LiCl and 7 mol of water. If 1 mol of LiCl⋅3H2O(s) is dissolved isothermally in this solution, what is the heat effect?

19.488 kJ

Explanation:

The overall reaction mechanism shows the reaction between LiCl and H₂O

    -------- (1)

             -------- (2)

                                    --------- (3)

            ---------- (4)

The overall reaction =

The heat effects of the above reactions from 1-4 respectively are in the order ; 11311.34 kJ, -857.49 kJ, -873.61 kJ and 439.288kJ respectively

The overall enthalpy change is:

at constant pressure;

Thus; Q = 1311.3 (kJ)  857.49 (kJ) -873.61 (kJ) + 439.288 (kJ)

Q = 19.488 kJ

Thus, the heat effect = 19.488 kJ after the addition of  1 mol of LiCl⋅3H2O(s)