The standard molar heat of formation of ethane, carbon dioxide and water (liquid) are -21.1, -94.1 and -68.3 kcal respectively. Calculate the standard heat of the following reaction :
`2C_2H_6 (g) + 7O_2(g) to 4CO_2(g) + 6H_2O(l)`

Explanation

To calculate the standard heat of the reaction given by:

\[ 2C_2H_6 (g) + 7O_2(g) \rightarrow 4CO_2(g) + 6H_2O(l) \]

we will use the standard molar heats of formation for each compound involved in the reaction. The formula to calculate the standard heat of the reaction (\( \Delta H^\circ_{reaction} \)) is:

\[
\Delta H^\circ_{reaction} = \sum (\Delta H^\circ_f \text{ of products}) - \sum (\Delta H^\circ_f \text{ of reactants})
...