Question

What will be the mass of ch4 methane in 1.8066*10^25 molecules

Answer 1

no. of moles = no. of molecules/Avagadro No

n = 1.8066×10^25/6.022×10^23
n = 0.3×10^2
n = 30

moles = mass/Molar mass

Molar mass of CH4 is 12+4×1 = 16
30= mass/16
mass= 30×16
mass = 480g

Answer 2

Mass of 1 mole of CH4 molecules=(12+4)g=16g

Mass of 6.022×10^23 CH4 molecules=16g

Mass of 1 CH4 molecule=16/(6.022×10^23) g

Mass of 1.8066×10^25 molecules

=(16×1.8066×10^25)/(6.022×10^23)

= 480 g