First we need to find the molar mass of hydrogen in periodic table and multiply it with the 2(quantity of hydrogen) (h2o) and then add 16 for oxygen.
Molar mas of H is 1.008 and quantity of H in h2o is 2. So 2x 1.008 + 16 = 18.016 g/1 mol and divide the molar mass with 25. So 25 divided by 18 is 1.39 moles.