Question

The enthalpy of combustion for octane (C8H18(l)), a key component of gasoline, is -5,074 kJ/mol. This value is the Hrxn for which of the following reactions? 2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(g) C8H18(l) + 12.5O2(g) 8CO2(g) + 9H2O(g) 16CO2(g) + 18H2O(g) 2C8H18(l) + 25O2(g) 8CO2(g) + 9H2O(g) C8H18(l) + 12.5O2(g)

Answer 1

The enthalpy of combustion for octane (C8H18) is -5,074 kJ/mol. This value corresponds to the reaction: 2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(g).

Step-by-step explanation:

The enthalpy of combustion for octane (C8H18) is -5,074 kJ/mol. This value corresponds to the reaction: 2C8H18(l) + 25O2(g) → 16CO2(g) + 18H2O(g). This means that when 2 moles of octane react with 25 moles of oxygen gas, 16 moles of carbon dioxide and 18 moles of water are produced, while releasing 5,074 kJ of heat.

Answer 2

C8H18(l) + 12.5O2(g)-------------------------> 8CO2(g) + 9H2O(g)

Step-by-step explanation:

The enthalpy of combustion for octane (C8H18(l)), a key component of gasoline, is -5,074 kJ/mol. This value is the Hrxn for which of the following reactions? 2C8H18(l) + 25O2(g) 16CO2(g) + 18H2O(g) C8H18(l) + 12.5O2(g) 8CO2(g) + 9H2O(g) 16CO2(g) + 18H2O(g) 2C8H18(l) + 25O2(g) 8CO2(g) + 9H2O(g) C8H18(l) + 12.5O2(g)

Enthalpy of combustion signifies a reaction where one mole of the compound completely combines with oxygen gas.

Enthalpy of combustion is the sum of enthalpy of formation on the product sides minus sum of enthalpy of the reaction on the reactant side. When the enthalpy of combustion is negative, then the reaction is exothermic(heat is given to the surrounding)

answer is

C8H18(l) + 12.5O2(g)-------------------------> 8CO2(g) + 9H2O(g)