What Is the Standard Molar Enthalpy Change D H Rxn

question 33

Multiple Choice

What is the standard molar enthalpy change D H rxn for the following reactions using the standard molar enthalpies of formations provided?
SiCl 4 ( ) + 2 H₂ O ( ) SiO₂ (s) + 4 HCl (g) D H rxn = ???
D H f (SiCl 4 ) = - 640.1 kJ/mol D H f (SiO₂ ) = - 910.9 kJ/mol D H f (H₂ O) = - 285.8 kJ/mol D H f (HCl) = - 92.3 kJ/mol

• A) - 2491.8 kJ/mol
• B) - 1929.1 kJ/mol
• C) - 77.3 kJ/mol
• D) - 68.4 kJ/mol
• E) None of these

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