Answer is: mass of methanol is 528.32 grams.
N(CH₃OH) = 9.93·10²⁴; number of methanol molecules.
n(CH₃OH) = N(CH₃OH) ÷ Na (Avogadro constant).
n(CH₃OH) = 9.93·10²⁴ ÷ 6.022·10²³ 1/mol.
n(CH₃OH) = 16.49 mol; amount of substance.
m(CH₃OH) = n(CH₃OH) · M(CH₃OH).
m(CH₃OH) = 16.49 mol · 32.04 g/mol.
m(CH₃OH) = 528.32 g.
