The molar heats of combustion of `C_(2)H_(2)(g),C` (graphite) and `H_(2)(g)` are 310.62 kcal, 94.05 kcal and 68.32 kcal respectively. Calculate the standard heat of formation of `C_(2)H_(2)(g)` .

Explanation

To calculate the standard heat of formation of \( C_2H_2(g) \), we will use Hess's law and the given molar heats of combustion for \( C_2H_2(g) \), graphite (C), and hydrogen gas (\( H_2(g) \)).

### Step-by-Step Solution:

1. **Write the combustion reactions**:
- For \( C_2H_2(g) \):
\[
C_2H_2(g) + \frac{5}{2} O_2(g) \rightarrow 2 CO_2(g) + H_2O(l) \quad \text{(ΔH = -310.62 kcal)}
...