Question #6e25b

1 Answer
May 23, 2017

193000C

Explanation:

The half reactions for this reaction are

2"H"_"2""O" + "2e"^-) rarr "O"_2(g) + "4H"^+"(aq)" + "4e"^-

"2H"^+ + "2e"^-) rarr "H"_2

2"H"_"2""O" + "2e"^-) rarr "O"_2(g) + "(""4H"^+"(aq)" + "4e"^-)")"

"4H"^+ + "4e"^-) rarr 2"H"_2

Overall reaction" "2H_2O rarr 2"H"_2 + O_2

This means that for every 2 mol of electrons 1 mole of "O"_2 and 2 mol of "H"_2 are formed

So if think clearly this is "stoichiometry" actually

And we are assuming that the electrolysis is done under standard conditions

"moles of "O_2 = "weight"/ "molar mass"

"2 mol" = "32g"/16

If 2 mol of "O"_2 are produced then if it's not a 100% yield and a 50%(which is in your case) yield for hydrogen .

This is because actually 4g H_2 should be produced. Maybe it got burnt up.Or the electrode working to make hydrogen was electric resistive.
But if 100% of O_2 is formed then the electricity used is the same.

2"H"_"2""O" + "2e"^-) rarr "O"_2(g) + "(""4H"^+"(aq)" + "4e"^-)")"

Multiply both sides with 2

4"H"_"2""O" + "4e"^-) rarr 2"O"_2(g) + "8H"^+"(aq)" + "8e"^-)

4 electrons are required.

Now you calculate the Coulombs using the electrons required

x" coulombs" xx "1 mol of electrons"/ "96500C" = 2C

x" coulombs" = "96500C" * "2C"

= 193000C

Now amps could be different