From the following data, calculate the standard enthalpy of formation of propane `Delta_(f)H^(Theta) CH_(4) = - 17 kcal mol^(-1)`
`Delta_(f)H^(Theta)C_(2)H_(6) =- 24 kcal mol^(-1), BE (C-H) = 99 kcal mol^(-1)`
`(C- C) = 84 kcal mol^(-1)`.

Explanation

To calculate the standard enthalpy of formation of propane (C₃H₈), we can use the given data and the concept of bond energies. The enthalpy of formation can be expressed in terms of the bond energies of the reactants and products involved in the formation of propane.

### Step-by-step Solution:

1. **Write the Formation Reaction for Propane:**
The formation reaction for propane from its elements in their standard states is:
\[
3C_{(s)} + 4H_{2(g)} \rightarrow C_3H_8_{(g)}
...