Question

How many actual molecules of methane are present in 32 grams of methane?

Answer 1

I mole is the weight in g equal to the molecular mass

Methane is CH4

So its molecular mass = mass of 1 carbon atom + 4 x mass of hydrogen atom

Work out that number

Then you have 32 g of methane: so work out how many moles that is (32/molecular mass of methane)

Every mole of a substance contains
6.02214129(27)×10^23 particles

(This is called Avagadro's number)