How many molecules of O2 are in 153.9 g O2?

2.895*10^24

Explanation:

mass of Oxygen give = 153.9g

molar mass of O2 molecule = 16*2=32g/mol

n = mole

To find the mole

n = mass / molar mass

n = 153.9/32

n=4.81mol.

To find the number of molecules of o

Nm = number of molecule

Nn = Number of mole

NA = number of Avogados

Nm = Nn * NA

Nm = 4.81 * 6.02*10^23

Nm = 2.895*10^24