How many #N# atoms are there in one mole of #N_2#?

1 Answer
Oct 3, 2016

Answer:

#2 xx N_"A"#

Explanation:

You know that one molecule of nitrogen gas, #"N"_color(blue)(2)#, contains two atoms of nitrogen, #color(blue)(2) xx "N"#.

Now, a mole is simply a very, very large collection of particles. In order to have one mole of things, let's say particles, you need to have #6.022 * 10^(23)# particles #-># this is known as Avogadro's constant and acts as the definition of the mole.

So, in one mole of nitrogen gas you have #6.022 * 10^(23)# molecules of nitrogen gas, #"N"_2#. But since each individual molecule consists of #2# atoms of nitrogen, the number of moles of nitrogen atoms will be twice that of nitrogen gas molecules.

#6.022 * 10^(23)color(red)(cancel(color(black)("molecules N"_2))) * (color(blue)(2)color(white)(a)"atoms of N")/(1color(red)(cancel(color(black)("molecule N"_2)))) #

# = 1.2044 * 10^(24)"taoms of N"#

Alternatively, you can express this as #color(blue)(2) xx N_"A"#, where #N_"A"# is Avogadro's constant..