Question

The whiye pigment TiO2 is prepared by the reaction of titanium tetrachloride, TiCl4, with water vapor in the gas phase:

TiCl4 + 2H2O2 ? TiO + 4HCl
How much heat is evolved in the production of exactly 1 mole of TiO2 under standard state conditions?

Answer 1

`\boxed{\text{62.1 kJ}}`

Step-by-step explanation:

The formula for calculating the enthalpy change of a reaction by using the enthalpies of formation of reactants and products is

`\Delta_{\text{r}}H^(\circ) = \sum \Delta_{\text{f}} H^(\circ) (\text{products}) - \sum\Delta_{\text{f}}H^(\circ) (\text{reactants})`

TiCl₄(g) + 2H₂O(g) ⟶ TiO₂(s) + 4HCl(g)

ΔH°f/kJ·mol⁻¹: -763.2 -241.828 -939.7 -92.307

`\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}}`