To find the number of moles from a mass given, simply look to the formula n (moles) = m (mass, g) / MM (molar mass). Mass was given, 36.04 Molar mass is the total atomic mass of all the atoms present. Water is H20, so that means 2 hydrogen and 1 oxygen. The atomic mass of hydrogen is 1 and atomic mass of oxygen is 16. Therefore MM= 1 + 1 + 16= 18. Plug that value in and the full equation is n = 36.04/18 n = 2.002 moles = 2 moles
