Now we will balance O. How many O2 molecules are needed to form one P4O10 molecule?

Answeramino acids;

Adialysis unit requires 78.5 l of water.the estimated digit is 5. 

Answer is: hydrogen is being oxidized.chemical reaction: co₂ + h₂ → co + h₂o.oxidation half reaction: h₂ → 2h⁺ + 2e⁻.reduction half reaction: c⁺⁴ + 2e⁻ → c⁺².oxidation is increase of oxidation number, hydrogen change oxidation number from neutral charge (in molecule of hydrogen) to oxidation number +1 (in water).