What is the mass of $0.513 mol Al _2 O _3$? Give your answer to the correct number of significant figures. (Molar mass of $Al _2 O _3=102.0 g / mol$)
$0.513 mol Al_2 O_3=\square g Al_2 O_3$
$0.513 mol Al_2 O_3=\square g Al_2 O_3$