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

One mole of methane has a mass of 4*1 + 12

= 16 grams.

So 32g is 2 moles of methane.

Now we use Avogadro's number:

I mole of an elements contains 6.022 * 10^23 molecules so the answer is 2 * 6.022 * 10^23

= 12.044 * 23 molecules.