Answer:
5.6 grams of water.
Explanation:
Please, notice that we can't see the spot with the question mark, so I will answer the question completely step by step.
We know that water is made from two hydrogen molecules and one oxygen molecule.
By looking at the atomic weight, we know that the weight of one mole of oxygen is:
16 grams.
While the weight of one mole of hydrogen is 1 gram (and we have two of these)
Then we have a total mass of 16 g + 2 g = 18 g
Now let's find what fraction of this is the oxygen, here we just need to take the quotient between the mass of oxygen and the total mass:
16g/18g = 0.89
Now, this means that if we have M grams of pure water, then we will have:
0.89*M grams of oxygen.
Ok, now let's use this to solve our problem, we want to find how many grams of water are made from 5 grams of oxygen.
Then let's write:
5 grams = 0.89*M grams
Where M represents the grams of water that we would get, here we just need to isolate M.
M = (5 g/0.89) = 5.6 grams
This means that out of 5 grams of oxygen, we can make 5.6 grams of water.