Calculate the∆Hrxnfor the following thermochemical equation:

When given the following:

• A. -296.8 kJ
• B. -148.4 kJ
• C. 148.4 kJ
• D. 296.8 kJ

Answer: (B)

Verified step by step guidance

1. Identify the given thermochemical equation: \( \text{S(s)} + \frac{3}{2} \text{O}_2\text{(g)} \rightarrow \text{SO}_3\text{(s)} \).
2. Recognize that the enthalpy change \( \Delta H_{rxn} \) for the reaction is what we need to calculate.
3. Understand that the enthalpy change for a reaction can be determined using Hess's Law, which states that the total enthalpy change is the sum of the enthalpy changes for each step of the reaction.
4. Examine the provided values: \(-296.8 \text{ kJ}\), \(-148.4 \text{ kJ}\), \(148.4 \text{ kJ}\), and \(296.8 \text{ kJ}\). These values might represent enthalpy changes for related reactions or processes.
5. Consider the stoichiometry of the reaction and the possible need to adjust the enthalpy values based on the coefficients in the balanced equation. For example, if the reaction is given for half the amount, you might need to multiply or divide the enthalpy value accordingly.