Answer: 4 moles of water(H20) is formed.
Explanation: The answer for the above equation is as follows:
If 4 moles of hydrogen (H2) are combined or added with 2 moles of oxygen(O2) then, it results in 4 moles of water (H2O).
4 moles of H2+2 moles of O2= 4 moles of H2O