Question

What is the mass in grams of 9.45*10^24 molecules of methanol (CH3OH)?

Answer 1

Number of moles:

1 mole ---------- 6.02x10²³ molecules
? moles --------- 9.45x10²⁴ molecules

1 x ( 9.45x10²⁴) / 6.02x10²³ =

9.45x10²⁴ / 6.02x10²³ => 15.69 moles of CH3OH

Therefore:

Molar mass CH3OH = 32.04 g/mol

1 mole ------------ 32.04 g
15.69 moles -----  mass methanol

Mass methanol  = 15.69 x 32.04 / 1 => 502.7076 g