Question

How long must a current of 1.20 A pass through a sulfuric acid solution in order to produce 25.0 mL of H2 gs at 25 degrees C and 1 atm pressure?

Answer 1

moles H2: PV/RT solve that.

Now for the charge per H2 molecule

H2SO4+2H2O>>2H2 + O2 + H2SO4

Each O loses two electrons, so each O2 loses 4 electrons, so then 2H2 gains 4 electrons, so each mole of H2 gains 2*avag number of electrons.

Now, what charge is that?

charge=chargeoneOneElectron*2*avagnumber
= 1.6E-19*2*6.12E23= ....

current*timeinSeconds= charge above
solve for time.