Question

(PLS HELP) A rigid tank 30.0L is filled with hydrogen gas as a fuel. The initial pressure is 16.0atm and the initial temperature is 298K. After the commissioning, the temperature remains 298K but the pressure was 4.0atm. Find a) and b)?

a) What is the molar of `H_2` burned during this operation?
b) What is the heat this positive hydrogen burns and releases?

Answer 1

Well, we can find `a` on the given data....

Explanation:

We use the Ideal Gas equation...

`n_"initial"=(PV)/(RT)=(16*atmxx30*L)/(0.0821*(L*atm)/(K^*mol)xx298*K)=19.62*mol`

`n_"final"=(PV)/(RT)=(4*atmxx30*L)/(0.0821*(L*atm)/(K^*mol)xx298*K)=4.90*mol`

And so ………….

`"moles of dihydrogen burnt"=n_"initial"-n_"final"=14.72*mol`

For `b` you need to supply the molar enthalpy of combustion for dihydrogen gas...i.e. `DeltaH_"rxn"^@` for...

`H_2(g) + 1/2O_2(g) rarr H_2O(l)` `;DeltaH_"rxn"^@=??`