What is the molar mass of water?

1 Answer
Jun 18, 2017

Answer:

A water molecule contains #3# #"atoms"#. These #3# #"atoms"# constitute #1# #"water molecule"#.

Explanation:

A #"water molecule"# contains #3# #"atoms"#: #2xxH#, and #1xxO#. That is, those 3 atoms, when appropriately chemically bound, constitute a water molecule.

We know that #18.01*g# of water contains #N_A# water molecules, where #N_A="Avogadro's number"=6.022xx10^23*mol^-1#, and we get the mass by adding the atomic masses appropriately, i.e. #(2xx1.00794+15.999)*g*mol^-1#.

How many atoms in an #18*g# mass of water?