Calculate the Change in Enthalpy Associated with the Combustion of Ethanol
How can we calculate the change in enthalpy associated with the combustion of ethanol?
Given data: Mass of ethanol = 322 g, Molar mass of ethanol = 46.07 g/mol, Heat of combustion of ethanol = -1367 kJ/mol.
Calculating the Change in Enthalpy:
To calculate the change in enthalpy associated with the combustion of ethanol, we need to use the heat of combustion (∆Hc) of ethanol and the molar mass of ethanol.
The balanced equation for the combustion of ethanol is C2H5OH + 3O2 -> 2CO2 + 3H2O.
The molar mass of ethanol (C2H5OH) is approximately 46.07 g/mol. We have 322 g of ethanol, which is equal to 322 g / 46.07 g/mol = 6.99 moles of ethanol.
The heat of combustion (∆Hc) of ethanol is approximately -1367 kJ/mol.
Now we can calculate the change in enthalpy (∆H) associated with the combustion of 322 g of ethanol: ∆H = ∆Hc x moles of ethanol ∆H = -1367 kJ/mol x 6.99 mol ∆H = -9554 kJ
Therefore, the change in enthalpy associated with the combustion of 322 g of ethanol is approximately -9554 kJ. The negative sign indicates that the reaction is exothermic, meaning it releases energy in the form of heat.