What is the mass, in grams, of 9.59×1024 molecules of methanol (CH3OH)?

Answer 1

molar mass CH3OH = 32.0 g/mol

First, find the moles of CH3OH and then convert that to grams.

moles CH3OH = 9.59x10²⁴ molecules x 1 mol / 6.02x10²³ molecules = 15.9 moles CH3OH

grams CH3OH = 15.9 moles x 32.0 g/mol = 509 g (3 sig. figs.)