The media is also ignorant, especially in the way it is portraying the issue.
ISLAMABAD: I, too, am sceptical about the so-called ‘water car’. However, the media is also ignorant, especially in the way it is portraying the issue. So, perhaps, we should try and examine the science behind it.
The thing to see is whether the energy produced by the combustion of hydrogen (which in turn depends on the mass of hydrogen produced and its calorific value) is greater than the electrical energy put into separating it from water. If that does happen, then this claim may be true. The point to note is that the electrical energy input for electrolysis is not the source of power, which is contained in the chemical energy in the hydrogen.
Consider the following analogy: use a small electrical charge to set off a tonne of explosives, and then use some of the energy released by the explosion to create another electrical charge to set off another tonne of explosives, and so on. No thermodynamic laws will be violated, since the explosives are being replenished. For the case of the ‘water car’, oxygen in the air replenishes the hydrogen during combustion to produce water.
Delving into the chemistry: the OH-H bond broken during electrolysis must require less energy than the energy released when whatever bonds are formed during the combustion — this, for the claim to be true. Keeping in mind that atmospheric oxygen plays a part, this is not a closed system. This energy balance must be favourable for the car to work, and this may turn out to not be the case.
Saad Malik
Published in The Express Tribune, August 5th, 2012.
