Hello! I can help you with this. First, convert them into it’s written out standard form. 10^4 is 10,000. 10,00 * 1.26 is 12,600. 10,000 * 2.5 is 25,000. 12,600 + 25,000 = 37,600 or 3.76 * 10^4 in scientific notation. The answer in scientific notation is 3.76 * 10^4.
In order to determine if a reactant is in excess or limiting, we must first know the required amount of reactants. This is referred to as the stoichometric amount of reactant, and it is obtained from the chemical equation.
From the equation, we form a ratio of the reactants. The reactant supplied in excess of that ratio is the excess reactant, while the other is the limiting reactant.
Answer: The enthalpy of the given reaction is 1234.8kJ/mol.
Explanation: Enthalpy change of the reaction is the amount of heat released or absorbed in a given chemical reaction.
Mathematically,

For the given reaction:





![\Delta H_{rxn}=\Delta H_f_{(C_2H_5OH)}+3\Delta H_f_{(O_2)}-[2\Delta H_f_{(CO_2)}+3\Delta H_f_{(H_2O)}]](https://tex.z-dn.net/?f=%5CDelta%20H_%7Brxn%7D%3D%5CDelta%20H_f_%7B%28C_2H_5OH%29%7D%2B3%5CDelta%20H_f_%7B%28O_2%29%7D-%5B2%5CDelta%20H_f_%7B%28CO_2%29%7D%2B3%5CDelta%20H_f_%7B%28H_2O%29%7D%5D)
Putting values in above equation, we get:
![\Delta H_{rxn}=[-277.6+3(0)]-[2(-393.5)+3(-241.8)]kJ/mol](https://tex.z-dn.net/?f=%5CDelta%20H_%7Brxn%7D%3D%5B-277.6%2B3%280%29%5D-%5B2%28-393.5%29%2B3%28-241.8%29%5DkJ%2Fmol)
