Why the amount of hydrogen is doubled from oxygen during electrolysis of water?

Answer 1

Because there are two hydrogen atoms and only one oxygen atom for each water molecule. The atomic volume of hydrogen is 14.4 cm3/mol and the atomic volume of oxygen is 14.0 cm3/mol so you are basically getting 2 units of volume from hydrogen and 1 unit of volume from oxygen for every molecule of water.

Answer 2

As each water molecule contains one atom of Oxygen and two atoms of Hydrogen you would expect electrolysis of water to produce twice as much Hydrogen as Oxygen.

As shown by the chemical formula H2O, each molecule of water is made of two atoms of hydrogen and one atom of oxygen.

Answer 3

well assuming they are both ideal gases (which they're not but its easier to explain and i think its an o.k. assumption to make) then you can use the equation:

pV=nRT ; Where: p - pressure (assume constant)

V - volume

n - number of moles

R - gas constant

T - temperature (constant)

You can then rearrange and say:

V=(nRT)/p ; where R, T and p are constant.

what you then find is that V is proportional to n (V depends linearly on n).

Now in the electrolysis of water you have the equation:

2 H2O --> 2 H2 + O2 - in this equation it is important to realize that the number of moles at the start must equal the number of moles at the end. At the start there are 4 hydrogen moles, so therefore there must be 4 at the end, hence 2 H2 and there are 2 oxygen moles, so there must be 2 oxygen moles at the end, hence O2.

Using the fact that n is proportional to V we can see there are twice as many moles of hydrogen than oxygen and so hydrogen takes up twice as much volume.

Answer 4

As each water molecule contains one atom of Oxygen and two atoms of Hydrogen you would expect electrolysis of water to produce twice as much Hydrogen as Oxygen.

Answer 5

There are twice as many atoms of hydrogen as oxygen, but not twice as much mass (weight).

Answer 6

Yes (for the atoms ratio), because the chemical formula of water is H2O.