How many molecules are in a sample of water with a mass of 44.99 grams?

1 Answer
Apr 3, 2016

Answer:

#(44.99*g)/(18.01*g*mol^-1)# #xx# #N_A#, where #N_A# #=# #"Avogadro's number "6.022xx10^23*mol^-1#.

Explanation:

By definition #1# mole of water has a mass of #18.01*g#. And in such a mass there are #N_A# water molecules.

The problem quotes a certain mass; we convert this to moles, and from this we get the number of molecules.

How many atoms are there in such a sample?