0.513 mol Al2O3 = g Al2O3

Molar mass (M) = mass(m) / number of moles (n)

To find the mass of Al2O3 first calculate it's molar mass

thus

M(Al2O3) = (27×2) + (16 × 3)

= 54 + 48

= 102g/mol

Mass of Al2O3 = molar mass × number of moles

= 102 × 0.513

= 52.326g of Al2O3

Hope this helps

i'm pretty sure its b i might be wrong though!