How many atoms in a #25.0*g# mass of water?

1 Answer
Mar 28, 2016

Answer:

We calculate the number of moles of water, and then multiply this number by #3N_A#

Explanation:

#"Moles of water"# #=# #(25.0*g)/("18.01 "g*mol^-1)# #=# #1.39*mol.#

In each mole of water there are #3# #mol# atoms.

So #"Number of atoms"# #=# #1.39*molxxN_Axx3" atoms "mol^-1# #=# #4.16xxN_A " atoms"#.

#N_A = "Avogadro's number"# #=# #6.022xx10^23#