Final answer:
To calculate the enthalpy change of the reaction, use the standard enthalpies of formation for the reactants and products, then apply the general formula ΔHoreaction = ∑ΔHof products - ∑ΔHof reactants. The reaction's enthalpy change would be the sum of the products' formation enthalpies minus the sum of the reactants' formation enthalpies.
Step-by-step explanation:
To calculate Δhrxn for the given reaction 5C(s) + 6H2(g) → C5H12(l), you will need to use standard enthalpies of formation for the reactants and products. First, write the reaction and then find the values of standard enthalpy of formation for each species involved from a reference source, such as a chemistry textbook or reliable database.
The general formula to calculate the enthalpy change of a reaction is:
ΔHoreaction = ∑ΔHof products - ∑ΔHof reactants
Let's assign hypothetical values for the sake of this example:
- Standard enthalpy of formation of C(s): 0 kJ/mol (reference)
- Standard enthalpy of formation of H2(g): 0 kJ/mol (reference)
- Standard enthalpy of formation of C5H12(l): -35 kJ/mol (hypothetical)
Apply the enthalpy of formation values to the general formula:
ΔHoreaction = (1 * -35 kJ/mol) - (5 * 0 kJ/mol + 6 * 0 kJ/mol)
ΔHrxn = -35 kJ
The enthalpy change for the reaction, ΔHrxn, would be -35 kJ under the hypothetical scenario where the enthalpy of formation for C5H12(l) is -35 kJ/mol, and for C(s) and H2(g) are both 0 kJ/mol.