A solution of ammonia and water contains 3.80×1025 water molecules and 5.80×1024 ammonia molecules. How many total hydrogen atoms are in this solution?

1 answer

3.80E25 H2O molecules x 2 = # H atoms in water molecules.

5.80E24 NH4 molecules x 4 = # H atoms in NH3 molecules.

Sum is total H atoms in both sets of molecules.