Answer:
The correct answer is 205.4 g Al
Explanation:
Given the enthalpy of fusion (ΔHf) of aluminum (Al), the amount of heat required to melt the substance is calculated as follows:
heat = ΔHf x moles Al
We have the following data:
ΔHf = 10.7 kJ/mol
heat= 81.4 kJ
So, we calculate the moles of Al we can melt:
moles =heat/ΔHf= 81.4 kJ/(10.7 kJ/mol)= 7.61 moles
The relation between moles and grams of Al is given by the molar mass of Al (27 g/mol). Thus, we multiply the moles of Al by the molar mass to calculate the grams of Al we can melt:
grams = 7.61 moles x 27 g/mol = 205.4 g
