Final Answer:
The specific gas constant (R) for the reactants and products in a spark ignition engine using gasoline (C8.26H15.5) as a fuel and operating with an equivalence ratio of 0.8 is approximately 8.314 J/(mol·K).
Step-by-step explanation:
The specific gas constant (R) is a fundamental thermodynamic property that relates the energy of a gas to its temperature and pressure. In the case of a spark ignition engine using gasoline as a fuel, the specific gas constant for the reactants and products can be determined based on the stoichiometry of the combustion reaction.
Gasoline primarily consists of hydrocarbons, and in this case, C8.26H15.5 represents a simplified molecular formula for gasoline. To find the specific gas constant, we first need to calculate the molecular weight of the fuel. This involves determining the molar masses of the individual elements in the molecular formula and summing them up.
Once the molecular weight is known, the specific gas constant can be calculated using the universal gas constant (8.314 J/(mol·K)) and the molecular weight of the fuel. The equivalence ratio of 0.8 indicates that the combustion process is not perfectly balanced, and this information is crucial for accurately determining the specific gas constant for the given operating conditions.
In summary, the specific gas constant is a key parameter for understanding the thermodynamic behavior of the reactants and products in the combustion process of a spark ignition engine using gasoline as a fuel with an equivalence ratio of 0.8.