Given the mass number of Aluminium is 27 and the mass number of Oxygen is 16, how many moles of Al2O3 are in 30g? (3 significant figures)
Molar Mass of Al2O3 = 27+27+16+16+16 = 102Mass = mol*Mr so mol = Mass/Mrmol = 30/102 = 0.294117... = 0.294 moles
