How many formula units in #5.88*mol# of #CaO_2#?

2 Answers
Jul 20, 2017

Answer:

Well how many eggs in 5 dozen eggs.........? And you mean on #CaO# not #CaO_2#.

Explanation:

The given question is precisely the same as that I asked in the opening, except that here I deal with MOLES not DOZENS.....

See here for a similar treatment.

#1*mol# of stuff unequivocally specifies #6.022xx10^23# individual items of that stuff, where #6.022xx10^23# is Old Avogadro's number, symbolized by #N_A#.

Now in each formula unit of #CaO#, there are TWO atoms.......

And so..................

#"number of atoms"-=2*"atoms"xx6.022xx10^23*mol^-1xx5.88*mol~=30*N_A#

What is the mass of this quantity of #CaO#?

Jul 20, 2017

Answer:

A #5.88# mole sample of #"CaO"# contains #3.54xx10^24# formula units of #"CaO"#.

Explanation:

There is no compound with the formula #"Ca"_2"O"#. The formula for calcium oxide is #"CaO"#. One mole of anything is #6.022xx10^23# of anything, including formula units. In order to determine the number of formula units in a #5.88# mole sample of #"CaO"#, multiply the given moles by #6.022xx10^23# formula units/mol#.

#5.88color(red)cancel(color(black)("mol CaO"))xx(6.022xx10^23 "formula units CaO")/(1color(red)cancel(color(black)("mol CaO")))=3.54xx10^24" formula units of CaO"#

Thanks to anor77.