Question

What mass of water could be obtained from a tank containing `20*atm` `H_2(g)` at `298*K`, whose volume is `150*L`?

Answer 1

I assume that your tank is filled with dihydrogen gas, not dioxygen gas....I get approx. a `2.2*kg` mass of water....

Explanation:

And we take the combustion reaction of dihydrogen...

`H_2(g) + 1/2O_2(g) rarrH_2O(l) + Delta`...

With respect to dihydrogen, we gots a molar quantity of....

`n_(H_2)=(PV)/(RT)=(20*atmxx150*L)/(0.0821*(L*atm)/(K*mol)*298*K)=122.6*mol`

And clearly, according to the given equation, if all this dihydrogen is combusted (with atmospheric dioxygen) we get an equivalent molar quantity of water...a mass of `122.6*molxx18.01*g*mol^-1=??*g`