Ostwald Process for Making Nitric Acid

In the Ostwald process, nitric acid is made from ammonia. What’s happening here is ammonia is producing nitric acid. Now, as you can see, the process isn’t quite that simple. Nitric acid is made from ammonia in three steps.

Starting out, we have ammonia. We have four moles of it, which is reacted with oxygen, which we see right here. This oxygen is at 850 degrees Celsius. Platinum is used as a catalyst.

From that, we get nitric oxide, which is that right there. We have four moles of that. Then, in addition, we have some water left over in the gas phase. From that, the nitric oxide reacts readily with oxygen, which we have right here.

That makes nitrogen dioxide, which is that right there. The nitrogen dioxide is right here, because it dissolves in water, which we see right here. Notice it’s in the liquid form.

From that, we get nitric acid. The nitric acid is right there. We have two moles of that. Notice also that we have nitric oxide. This is nitric acid, but this is nitric oxide.

This nitric oxide can be converted back into nitrogen dioxide, which is that right there. It can be used to make more nitric acid. Usually, we would think of this as something that’s just left over, because we’re going for this, but this leftover can be used to make more of the product we’re trying to obtain.

It’s very helpful. Nitric acid is a strong oxidizing agent. In fact, one of its main uses is to produce fertilizers. Again, the Ostwald process is a three-step process to make nitric acid from ammonia.