How many total atoms are in 0.410 g of #P_2O_5?#

1 Answer
Oct 2, 2016

Answer:

Approx. #126xx10^20*"atoms of phosphorus and oxygen."#

Explanation:

#P_2O_5# has a molar mass of #141.94*g*mol^-1#.

And thus there is a molar quantity of #(0.410*g)/(141.95*g*mol^-1)# #=# #2.89xx10^-3*mol#.

Because there are #6.022xx10^23# particles in a mole by definition, there are thus,

#2.89xx10^-3*molxx6.022xx10^23*mol^-1xx7*"atoms"#

#=# #"how many atoms"#.

Note the actual molecule is #P_4O_10#; had I worked out the problem with this formulation I would have got precisely the same result.