Answer:
[tex]\boxed{\text{62.1 kJ}}[/tex]
Explanation:
The formula for calculating the enthalpy change of a reaction by using the enthalpies of formation of reactants and products is
[tex]\Delta_{\text{r}}H^{\circ} = \sum \Delta_{\text{f}} H^{\circ} (\text{products}) - \sum\Delta_{\text{f}}H^{\circ} (\text{reactants})[/tex]
TiCl₄(g) + 2H₂O(g) ⟶ TiO₂(s) + 4HCl(g)
ΔH°f/kJ·mol⁻¹: -763.2 -241.828 -939.7 -92.307
[tex]\begin{array}{rcl}\Delta_{\text{r}}H^{\circ} & = & [-939.7 + 4(-92.307)] - [-763.2 + 2(-241.828)\\& = & [-939.7 - 369.228] - [-763.2 - 483.656]\\& = & -1308.928 + 1246.856\\& = & \mathbf{-62.1}\\\end{array}\\\text{The amount of heat evolved is } \boxed{\textbf{62.1 kJ}}[/tex]
