Answer:
121.37 moles.
Explanation:
Always one mole of any molecule contains Avogadro number of molecules.
So one mole of methane contains 6.023*10^23 molecules.
Now we need number of moles of methane in 7.31*10^25 molecules.
This is just cross multiplication stuff.
6.023*10^23 molecules —————- 1 mole
7.31*10^25 molecules ——————- ?
= (7.31*10^25) / (6.023*10^23)
= 121.37 moles.
