"drainage" of fuel cell vehicle?

The fuel cell vehicle is driven by the energy released from a reaction between hydrogen and oxygen. In chemical equation, the reaction is described by:
2H₂ + O₂ --> 2H₂O ...(1)
The right side of this equation is H₂O, meaning that the fuel cell vehicle discharges water of quantity same as the consumed hydrogen.

One day I wondered "how much of water does a fuel cell vehicle discharge"?
Here this post is the answer to myself on this aspect.

"MIRAI", developped by Toyota Morter, is one of the commercially available fuel cell vehicle.
According to the website by Toyota Morter Corpoation, MIRAI of the grade G "Excecutive Package" can drive for 152 [km kg^-1]^[1]. By taking the inverse, we learn that MIRAI requires 6.6 [g] of hydrogen molecule to drive for 1 [km]. Because the molecular mass of hydrogen and water molecules are 2.0 and 18, respectively, a fuel cell vehicle generates 59 [g] of water after a drive of 1 [km].

By the way, the volume of hydrogen tank is 141 [L], which can store approximately 5.6 [kg] of hydrogen.
Hence, with a tank full of hydrogen, a fuel cell vehicle can drive for roughly 850 [km] in total (5.6 [kg] * 152 [km kg^-1])

The discharge of substantial ammount of water is a unique issue of fuel cell vehicle...? No, the same is true for gasoline-powered vehicle.
Next post calculate the drainage of water by gasoline-powered vehicle.

References

1. トヨタ自動車株式会社, "燃費（燃料消費率）はどれくらいですか？", https://faq.toyota.jp/faq/show/4914?site_domain=default (accessed on 2022/02/01)
2. トヨタ自動車株式会社, "水素満充填にはどれくらいの燃料代がかかりますか？", https://faq.toyota.jp/faq/show/4930?site_domain=default (accessed on 2022/02/01)