How many molecules of Oxygen (O2) are in 4.7 moles?

Question

I'm having some problems with my Chemistry class and could use some help

Answer 1

We know that there are Avogadro's number of molecules in 1 mole of molecules:

 

1 mole of molecules contains 6.023 x 10²³ molecules

 

Using dimensional analysis:

 

4.7 moles O₂ x (6.023 x 10²³ molecules O₂/mole O₂) = 4.7 x 6.023 x 10²³ molecules = 2.41 x 10²⁴ molecules O₂

 

There are 2.41 x 10²⁴ molecules O₂ in 4.7 moles O₂.