NITROGEN OXIDES
NOx
WHAT do these pictures have in common?
What do they have to do with this experiment?
Is NO really just all bad?

They all are generating or about to generate nitrogen oxides!

Certainly it is not unexpected to see toxic fumes generated in the chem lab. After all thats what chemistry is noted for.
But cars?
At high temperatures, such as in a car engine, the following takes place.

N2 + O2 ----> 2 NO

This combination is very unfavorable and even at high temperatures it occurs to less than 1%. If this were not so, we would not have any oxygen left in our atmosphere. ( You figure it out. The molar ratio of nitrogen to oxygen in air is about 4:1) And if your catalytic converter is working properly, much of this nitric oxide is converted back into nitrogen and oxygen. New Jersey's Motor Vehicle Inspection Stations see to this. Never-the-less, with so many cars running for so many hours, cars are a major source of NOx pollution.

But what is with the all-American hot dog? Is nothing sacred?

Well, again, figure it out for yourself.

On the left is the ingredient label from a package of Hot Dogs. Almost all sausage contains Sodium Nitrite in small amounts ( it is the next to last item here) .

It is a preservative which keeps the sausage from spoiling.

And so what happens when the chewed up hotdog hits your stomach?

2 NO2- + HCl -------> NO + NO2 + H2O +Cl-

The combination of nitrogen and oxygen to form nitric oxides takes place only when extra energy is added to air. The combustion temperature of a cars engine provides this extra energy. What do you think happens during a thunder storm when a lightning bolt zaps through the air?

The VERDICT on NO
Is Nitric Oxide valuable or is it harmful?

Nitric Oxide is a gas which converts readily to Nitric Acid.
4 NO + 2 H2O +3O2 ----> 4 HNO3

For the following reasons it is HARMFUL

  1. When inhaled it is destructive to lung tissue causing lung disorders and possibly even death.
  2. In streams and water supplies, it can increase the pH and destroy plant and animal life.
  3. Acid rain dissolves concrete and marble as well as metal. Many of our cities are dissolving and crumbling. Many statues and monuments are being destroyed.
  4. In the upper atmosphere it destroys the ozone layer. 2 NO + O3 ----> N2O5

Yet the following make it VALUABLE

  1. Nitrates are useful as fertilizers. Wheras animals and most plants can not use Nitrogen gas, N2, directly to produce protein, nitrates are much more readily converted. The nitrates produced during a thunder storm assist plant growth.
  2. As noted above, in the lungs, NO is destructively toxic. Yet NO is generated in the body in trace amounts to act as a neurotransmitter to control blood pressure and other functions.

RWK 1997