How much heat (in kilojoules) is released on reaction of 5.30 g of Al?
Reaction with what.
To determine the amount of heat released in the reaction, we need to know the specific reaction for aluminum (Al) and the corresponding enthalpy change, also known as the heat of reaction (∆H).
The reaction for aluminum combustion is typically written as:
4 Al(s) + 3 O2(g) → 2 Al2O3(s)
To find the heat released (∆H) from this reaction, we would typically refer to a table of standard enthalpy of formation values. However, if this information is not available, we can approximate it by using the average bond enthalpy method.
The average bond enthalpy method involves calculating the energy needed to break the bonds in the reactants and the energy released in forming the bonds in the products. The difference between these two quantities will give us an estimate of the enthalpy change (∆H) for the reaction.
For aluminum (Al), we need to consider the energy required to break the Al-Al bonds (436 kJ/mol) in the reactants.
First, we calculate the number of moles of aluminum (Al) in 5.30 g using its molar mass:
Molar mass of Al = 26.98 g/mol
moles of Al = mass of Al / molar mass of Al
= 5.30 g / 26.98 g/mol
Next, we calculate the energy required to break the bonds:
Energy required to break bonds = moles of Al * bond energy of Al-Al
Finally, we convert the energy to kilojoules (kJ):
Energy required to break bonds (kJ) = Energy required to break bonds (J) / 1000
Note: It is important to consider that this calculation provides an estimate and may not be as accurate as using standard enthalpy of formation values.
Therefore, with the given information for the reaction and the bond energy of Al-Al, we can compute the amount of heat released during the reaction.