Question #f6b8c

1 Answer
Aug 27, 2017

Answer:

#4.187 * 10^(25)#

Explanation:

For starters, you know that each molecule of carbon dioxide, #"CO"_2#, contains

  • one atom of carbon, #1 xx "C"#
  • two atoms of oxygen, #2 xx "O"#

This means that every mole of carbon dioxide will contain #2# moles of oxygen atoms.

You can thus say that your sample will contain

#34.77 color(red)(cancel(color(black)("moles CO"_2))) * "2 moles O"/(1color(red)(cancel(color(black)("mole CO"_2)))) = "69.54 moles O"#

Now, in order to have #1# mole of oxygen atoms, you need to have #6.022 * 10^(23)# atoms of oxygen #-># this is given by Avogadro's constant.

This means that your sample will contain a total of

#69.54 color(red)(cancel(color(black)("moles O"))) * (6.022 * 10^(23)color(white)(.)"atoms O")/(1color(red)(cancel(color(black)("mole O"))))#

# = color(darkgreen)(ul(color(black)(4.187 * 10^(25)color(white)(.)"atoms O")))#

The answer is rounded to four sig figs, the number of sig figs you have for the number of moles of carbon dioxide.