Respuesta :
Answer:
The enthalpy of the dissociation of the magnesium chloride is -168.2 kJ/mol.
Explanation:
Mass of magnesium chloride = 0.620 g
Moles of magnesium chloride = [tex]\frac{0.620 g}{95 g/mol}=0.006526 mol[/tex]
Mass of water = 112.00 g
Mass of solution, m = 0.62 g + 112 g =112.62 g
Heat capacity of the solution = c = [tex]4.184J/g^oC[/tex]
Initial temperature of the solution = [tex]T_1=25.00^oC[/tex]
Final temperature of the solution = [tex]T_2=27.33^oC[/tex]
Heat gained by solution = Q
[tex]Q=m\times c\times (T_2-T_1)[/tex]
[tex]Q=112.620 g\times 4.184J/g^oC\times (27.33^oC-25.00^oC)[/tex]
Q = 1,097.90 J =1.09790 kJ ≈ 1.098 kJ
Enthalpy of the dissociation magnesium chloride :
[tex]\Delta H_{diss}=-\frac{Q}{n}=\frac{-1.098 kJ}{0.006526 mol}=-168.2 kJ/mol[/tex]
The enthalpy of the dissociation of the magnesium chloride is -168.2 kJ/mol.
