How many electrons in ONE MOLE of carbon dioxide?

3 Answers
Apr 8, 2017

first calculate moles of # CO2 #

Explanation:

first calculate the moles of # CO2 # = 100/44
= 2.27 mol
now number of electrons in # CO2 # are obtained by adding total electrons in each of the three atoms i.e. two O and one C = 6+8+8
= 22
thus one mole of # CO2 # has # 22 * 6.022 * 10^23 # electrons and 2.27 mol has # 2.27 * 22 * 6.022 * 10^23 # electrons = # 301.1 * 10^23 # electrons

Apr 8, 2017

#3 * 10^(25)#

Explanation:

The first thing to do here is to calculate the number of moles of carbon dioxide present in your sample. To do that, use the compound's molar mass

#100 color(red)(cancel(color(black)("g"))) * "1 mole CO"_2/(44.0color(red)(cancel(color(black)("g")))) = "2.27 moles CO"_2#

Next, use Avogadro's constant to figure out the number of molecules of carbon dioxide present in the sample.

#2.27 color(red)(cancel(color(black)("moles CO"_2))) * (6.022 * 10^(23)color(white)(.)"molecules CO"_2)/(1color(red)(cancel(color(black)("mole CO"_2))))#

# =1.37 * 10^(24)# #"molecules CO"_2#

Now, every molecule of carbon dioxide contains

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

http://grrebs.ete.inrs.ca/en/csc/csc_co2/

This means that your sample contains

#1.37 * 10^(24)color(red)(cancel(color(black)("molecules CO"_2))) * "1 atom C"/(1color(red)(cancel(color(black)("molecule CO"_2))))#

# = 1.38 * 10^(24)# #"atoms of C"#

and

#1.37 * 10^(24) color(red)(cancel(color(black)("molecules CO"_2))) * "2 atoms O"/(1 color(red)(cancel(color(black)("molecule CO"_2))))#

# = 2.74 * 10^(24)# #"atoms of O"#

Next, grab a periodic Table and look for the atomic numbers of the two elements. You will find

#"For C: " Z = 6#

#"For O: " Z = 8#

As you know, a neutral atom has equal numbers of protons located inside its nucleus and electrons surrounding the nucleus.

Therefore, you can say that every atom of carbon will contain #6# electrons and every atom of oxygen will contain #8# electrons.

This means that you will have

#"total no. of e"^(-) = overbrace(6 * 1.37 * 10^(24))^(color(blue)("coming from C atoms")) + overbrace(8 * 2.74 * 10^(24))^(color(purple)("coming from O atoms"))#

#"total no. of e"^(-) = (8.22 + 21.92) * 10^(24)#

which gets you

#color(darkgreen)(ul(color(black)("total no. of e"^(-) = 3 * 10^(25))))#

The answer must be rounded to one significant figure, the number of sig figs you have for the mass of carbon dioxide.

Apr 9, 2017

Approx. #3xx10^25# #"electrons........"#

Explanation:

First, we calculate the number of electrons in ONE MOLECULE of #CO_2#. There is ONE CARBON ATOM, that is 6 electrons; and TWO OXYGEN ATOMS, that is 16 electrons, i.e. 22 electrons per molecule.

And then we calculate the number of carbon dioxide molecules in a mass of #100*g# of gas. How do we do this? We use the mole as a counting unit, i.e. #6.022xx10^23# molecules of #CO_2# have a mass of #(12.01+2xx15.999)*g*mol^-1=44.0*g*mol^-1#

#"Moles of carbon dioxide"# #=# #(100*g)/(44.01*g*mol^-1)=2.27*mol#.

And (finally) we solve the product:

#22xx(100*g)/(44.01*g*mol^-1)xx6.022xx10^23*"electrons"*mol^-1=#

#"how many electrons...........?"#