From a laboratory process, a student collects 28.0 g of hydrogen and 224.0 g of oxygen. how much water was originally involved in the process?

Chemical reaction is given as :

Here, 2 moles of water gives 2 moles of hydrogen and one mole of oxygen.

Mass of hydrogen =  28.0 g (given)

Mass of oxygen = 224.0 g (given)

Number of moles =

Thus, number of moles of hydrogen =

= 14 moles of hydrogen

Number of moles of oxygen=

= 7 moles of oxygen

Now, to find the amount of water:

= 252 g of water.

Thus, amount of water is 252 g (involved in the process).