The ratio by the number of atoms for water will always be H : O = 2 : 1 - Science - Atoms and Molecules

Question

The ratio by the number of atoms for water will
always be H : O = 2 : 1 Thus, 18 g of water contains 2 g of
hydrogen and 16 g of oxygen
i can understand that the ratio of h = 2 so 2 g of
hydrogen contained in the water but why we have taken the oxygen as
16 g but it is given that the ratio of o = 1 pls explain i need you
help experts pls

Kirti Gogia · Accepted Answer

Please note that here we are referring to the ratio of number of
atoms and not the ratio of masses of atoms In a molecule of water,
hydrogen and oxygen are present in the ratio H : O = 2 : 1 That is
the ratio of number of atoms of hydrogen to oxygen is 2 : 1
Now the mass of one mole of hydrogen is 1 grams and the mass of
one mole of oxygen is 16 grams As in water there are two atoms of
hydrogen and one atom of oxygen, therefore one mole of water
= 2 moles of hydrogen atom + one mole of oxygen atom
= 2 x (1) g + (16) g
= 18 g