Aluminum metal can be produced by reducing solid aluminum oxide (Al2O3) with carbon (graphite). Carbon monoxide is the other product. What is the enthalpy change (∆H° in kJ) when 25.0 g of aluminum metal is produced in this manner? You will need to balance the chemical equation.
2Al2O3 + 3C ==> 4Al + 3CO2
25.0 g Al metal. Atomic mass Al = 27
You will need to calculate the dHrxn as above. So you look up dHo formation for CO2, Al metal (it is zero), C( it is zero) and Al2O3.
The dHo rxn = (n*dHo formation products) - (n*dHo formation reactants)
Then dHo rxn * (25.0/4*27) = ?
Why did the aluminum go to therapy?
Because it had an enthalpy change and needed a little "Al"leviation!
But in all seriousness, to determine the enthalpy change when 25.0 g of aluminum metal is produced, we need to balance the chemical equation first. The balanced equation for the reaction is:
2 Al2O3 + 3 C → 4 Al + 3 CO
To calculate the enthalpy change, we need the enthalpy of formation for aluminum oxide (Al2O3) and carbon monoxide (CO). The enthalpy of formation for Al2O3 is -1669.8 kJ/mol, and for CO it is -110.5 kJ/mol.
Since 2 moles of Al2O3 produce 4 moles of Al, we'll use a stoichiometry factor of 4 in our calculations.
First, we need to calculate the moles of Al produced:
Molar mass of Al = 26.98 g/mol
Moles of Al = (25.0 g / 26.98 g/mol) * 4 = 3.71 moles of Al
Next, we use the enthalpies of formation to calculate the enthalpy change:
∆H° = (3.71 moles of Al) * (∆H° of Al) - (3 moles of CO) * (∆H° of CO) + (2 moles of Al2O3) * (∆H° of Al2O3)
∆H° = (3.71 * 0 kJ/mol) - (3 * -110.5 kJ/mol) + (2 * (-1669.8 kJ/mol))
∆H° = 0 kJ/mol + 331.5 kJ/mol - 3339.6 kJ/mol
∆H° = -3008.1 kJ/mol
To calculate the enthalpy change for 25.0 g of aluminum metal, we use the molar mass of aluminum:
Enthalpy change = (∆H° / moles of Al) * mass of Al
Enthalpy change = (-3008.1 kJ/mol / 3.71 moles of Al) * 25.0 g
Enthalpy change = -508.9 kJ (rounded to 3 significant figures)
So, the enthalpy change when 25.0 g of aluminum metal is produced in this manner is approximately -508.9 kJ.
To determine the enthalpy change of the reaction, we first need to balance the chemical equation:
2Al2O3 + 3C → 4Al + 3CO
From the balanced equation, we can see that 2 moles of Al2O3 produce 4 moles of Al.
Next, we need to calculate the molar mass of Al:
Molar mass of Al = atomic mass of Al = 26.98 g/mol
Now, we can calculate the number of moles of Al produced:
Moles of Al = (mass of Al) / (molar mass of Al)
= 25.0 g / 26.98 g/mol
Finally, we can calculate the enthalpy change using the equation:
∆H = (moles of Al) * (enthalpy change per mole of Al)
= (moles of Al) * (∆H°)
The enthalpy change (∆H°) can be found from reference tables or using thermodynamic data. Let's assume it is -393.5 kJ/mol for this reaction.
∆H = (25.0 g / 26.98 g/mol) * (-393.5 kJ/mol)
Now we can calculate the enthalpy change (∆H):
∆H = (0.9261 mol) * (-393.5 kJ/mol)
To solve this problem, we need to first balance the chemical equation for the reaction between solid aluminum oxide and carbon. The balanced equation is:
2 Al2O3 + 3 C → 4 Al + 3 CO
According to the balanced equation, for every 2 moles of Al2O3, we produce 4 moles of Al. We need to find the number of moles of Al produced from 25.0 g of Al2O3.
First, we need to calculate the molar mass of Al2O3:
2(Al) + 3(O) = 2(26.98 g/mol) + 3(16.00 g/mol) = 101.96 g/mol
Next, we can calculate the number of moles of Al2O3:
moles = mass / molar mass = 25.0 g / 101.96 g/mol
Now, we need to use the mole ratio between Al2O3 and Al to find the number of moles of Al produced. From the balanced equation, we know that 2 moles of Al2O3 produces 4 moles of Al:
moles of Al = moles of Al2O3 * (4 moles Al / 2 moles Al2O3)
Finally, we can calculate the enthalpy change (∆H°) when 25.0 g of aluminum metal is produced. The standard enthalpy change (∆H°) can be found by multiplying the moles of Al by the enthalpy change per mole of Al.
∆H° (kJ) = moles of Al * ∆H° per mole of Al
Note: The standard enthalpy change value for this reaction is not provided in the question. You would need to obtain this value from a reliable source or perform the experiment to determine it.
I hope this explanation helps you understand the process of solving the problem!