Answer: 2.438967 x 10^24 atoms of O in NaHCO3
Step-by-step explanation:
Given: 1.35 Moles of NaHCO3
In each mole of NaHCO3, there are 3 oxygen atoms. In 1.35 moles of NaHCO3, there are 1.35 x 3 moles of oxygen atoms.
1.35 x 3 = 4.05 total moles of O
In 1 mole, there are 6.0221408 x 10^23 atoms. In 4.05 moles of O, there are 4.05 x 6.0221408 x 10^23 oxygen atoms.
4.05 x 6.0221408 x 10^23 = 2.438967 x 10^24 atoms of O