Aballoon contains 0.15 moles of co2 gas. how many molecules of co2 are in the balloon?

1- One mole is = 6.02 x 10^23 of anything, So one mole of atoms is 6.02x10^23.

2- when the balloon contains 0.15 moles of Co2 gas so:

the no.of molecules of Co2 = 0.15 x 6.02x 10^23

                                              = 9.0 x 10^22

Butterfly wingspan is 7.7