Answer:
Explanation:
The formula for calculating the enthalpy change of a reaction by using the enthalpies of formation of reactants and products is
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}}](https://tex.z-dn.net/?f=%5Cbegin%7Barray%7D%7Brcl%7D%5CDelta_%7B%5Ctext%7Br%7D%7DH%5E%7B%5Ccirc%7D%20%26%20%3D%20%26%20%5B-939.7%20%2B%204%28-92.307%29%5D%20-%20%5B-763.2%20%2B%202%28-241.828%29%5C%5C%26%20%3D%20%26%20%5B-939.7%20-%20369.228%5D%20-%20%5B-763.2%20-%20483.656%5D%5C%5C%26%20%3D%20%26%20-1308.928%20%2B%201246.856%5C%5C%26%20%3D%20%26%20%5Cmathbf%7B-62.1%7D%5C%5C%5Cend%7Barray%7D%5C%5C%5Ctext%7BThe%20amount%20of%20heat%20evolved%20is%20%7D%20%5Cboxed%7B%5Ctextbf%7B62.1%20kJ%7D%7D)
Answer: This contains magnesium, Mg2+, and hydroxide, OH–
, ions. Each magnesium ion is +2 and
each hydroxide ion is -1: two -1 ions are needed for one +2 ion, and the formula for magnesium
hydroxide is Mg(OH)2. The (OH)2 indicates there are two OH–
ions. In a formula unit of
Mg(OH)2, there are one magnesium ion and two hydroxide ions; or one magnesium, two
oxygen, and two hydrogen atoms. The subscript multiplies everything in ( )
hope that helped!!
