Final answer:
To find the number of moles of Al2O3 in the sample containing 7.71x10^24 molecules, divide the number of molecules by Avogadro's number (6.022x10^23). The calculation shows there are 12.80 moles of Al2O3 in the sample.
Step-by-step explanation:
The student asked how many moles of Al2O3 (aluminum oxide) are in a sample containing 7.71x1024 molecules of Al2O3. To calculate the number of moles from the number of molecules, we use Avogadro's number, which is 6.022x1023 molecules per mole.
To find the moles of Al2O3, we divide the given number of molecules by Avogadro's number:
Moles of Al2O3 = (7.71x1024 molecules) / (6.022x1023 molecules/mol)
Performing the calculation provides the number of moles of Al2O3 in the sample:
Moles of Al2O3 = 12.80 moles
Therefore, the bauxite ore sample contains 12.80 moles of aluminum oxide.