How many oxygen atoms in a mass of #132*g# with respect to carbon dioxide?

2 Answers
Apr 17, 2016

Answer:

There are #3# #mol# of #CO_2# in such a mass. Thus there are #6xxN_A# individual oxygen atoms.

Explanation:

What is #N_A#? It is simply #"Avogadro's number"#, #6.022xx10^23*mol^-1#.

If I have #6.022xx10^23# individual items of stuff, I have a mole of that stuff. #1# #mol# of #CO_2# is equivalent to a mass #44.0*g#; #12.01# #g# of #C#, and #32.0# #g# of #O#.

Apr 17, 2016

Answer:

#36.132 times 10^23 # oxygen atoms

Explanation:

If we work out the relative formula mass of #CO_2#

Relative atomic mass, #A_r# of # C= 12#
Relative atomic mass, #A_r# of # O=16#, so....

#M_r# of # CO_2 =44#

The number of moles of a substance is given by :

#"mass in grams" /(M_r)#

So in this case:

#132/44=3*"moles"#

One mole contains #6.022times 10^23# molecules (Avogadro's number).

So 3 moles contains #18.066 times 10^23# molecules.

Each molecule contains 2 oxygen atoms, so there will be #36.132 times 10^23 #oxygen atoms