Compute the amount of heat released (absolute value) when 1.1 kg of liquid ethanol is burned in excess oxygen to make carbon dioxide and liquid water
Write the equation and balance it. Look up the delta Hf values. Then
deltaHrxn = (n*deltaHf products) - (n*deltaHf reactants).
n is the coefficient for the appropriate gas you look up. Post your work if you get stuck.
To compute the amount of heat released when ethanol is burned, we need to use the concept of the heat of combustion. The heat of combustion is the amount of heat released when one mole of a substance is completely burned in excess oxygen.
The balanced chemical equation for the combustion of ethanol (C2H5OH) is:
C2H5OH + 3O2 → 2CO2 + 3H2O
From this equation, we can see that one mole of ethanol produces 2 moles of carbon dioxide and 3 moles of water.
To calculate the heat released during the combustion process, we need to know the heat of combustion value for ethanol. The heat of combustion of ethanol is approximately 1366 kJ/mol.
First, we need to calculate the number of moles of ethanol in 1.1 kg. The molar mass of ethanol (C2H5OH) is approximately 46.07 g/mol.
Number of moles = Mass in grams / Molar mass
Number of moles = 1100 g / 46.07 g/mol
Number of moles = 23.8756 mol
Now, we can calculate the amount of heat released using the following formula:
Heat released = moles of ethanol * heat of combustion
Heat released = 23.8756 mol * 1366 kJ/mol
Heat released = 32,574.2696 kJ
Therefore, approximately 32,574.27 kJ of heat is released when 1.1 kg of ethanol is burned completely in excess oxygen.