Question

What is the mass (in grams) of 6.15 × 1025 molecules of carbon dioxide?

Answer 1

Avogadro's Number and Stoichiometry

To convert between moles and molecules, we can multiply the number of moles by Avogadro's number:
`6.02*10^(23)`

To convert between moles and mass, multiply the moles by the molar mass of the compound.

Solving the Question

We're given:

• 
  `6.15*10^(25)` molecules

Divide this by Avogadro's number:

`(6.15*10^(25))/(6.02*10^(23))\\\\= 102.1594684\hspace{4}mol`

Multiply by molar mass (44.01 from Chemspider):

`102.1594684*44.01\\=4.5*10^3\hspace{4}g`

Answer

`4.5*10^3\hspace{4}g`