A Brief Note on Nitrogen Monoxide, NO

Introduction

Nitrogen monoxide is a colorless gaseous compound also known as nitric oxide and has the formula NO. It is one of the most common nitrogen oxides. Nitric oxide is a free radical, meaning it possesses an unpaired electron, which is sometimes indicated in its chemical formula NO. 

The class of heteronuclear diatomic molecules, a type of molecule whose study led to the development of early modern chemical bonding theories. Nitric oxide is an important intermediate in industrial chemistry that originates in combustion systems and can be produced by thunderstorm lightning. Nitric oxide plays a role in a variety of physiological and pathological processes in animals, including humans. The “Molecule of the Year ” award was given to it in 1992. The discovery of nitric oxide’s role as a cardiovascular signalling molecule garnered the Nobel Prize in Physiology or Medicine in 1998.

Preparation of Nitrogen Monoxide 

In the Ostwald process, nitric oxide is produced in commercial settings by oxidising ammonia at 750–900 °C (usually 850 °C) with platinum as a catalyst at 750–900 °C (typically 850 °C):  

4NH3 + 5O2 → 4NO + 6H2O  

The uncatalyzed endothermic reaction of oxygen (O2) and nitrogen (N2) caused by lightning at high temperatures (>2000 °C) has not been turned into a commercially viable synthesis. 

N2 + O2 → 2NO

Laboratory Method 

In the laboratory, Nitrogen monoxide is prepared by the reduction of dilute nitric acid with copper–

 8HNO3 + 3Cu → 3Cu(NO3)2 + 4H2O + 2NO 

The reduction of nitrous acid in the form of sodium nitrite or potassium nitrite is an alternate route:

2 NaNO2 + 2 NaI + 2 H2SO4 → I2 + 2Na2SO4 + 2H2O + 2NO

2 NaNO2 + 2 FeSO4 + 3 H2SO4 → Fe2(SO4)3 + 2 NaHSO4 + 2H2O + 2NO

3 KNO2 + KNO3 + Cr2O3 → 2 K2CrO4 + 4NO

The iron(II) sulphate method is straightforward and has been tested in student labs. For nitric oxide production, so-called NONOate chemicals are also employed.

Effects of Nitrogen Monoxide 

1. Acid rain deposition

 Nitrogen dioxide (NO2) is formed when nitric oxide combines with the hydroperoxy radical (HO•2), which can then react with a hydroxyl radical (•OH) to make nitric acid (HNO3):

• NO + HO•2 → •NO2 + •OH
• NO2 + •OH → HNO3

Acid rain is caused by the combination of nitric acid and sulfuric acid.

1. Ozone depletion

NO contributes to the ozone layer’s depletion. O2 and nitrogen dioxide are formed when nitric oxide combines with stratospheric ozone:

 NO + O3 → NO2 + O2

NO concentrations in control volumes are also measured using this process.

1. Precursor to the formation of NO2

As mentioned in the section on acid deposition, nitric oxide can be converted to nitrogen dioxide (through the hydroperoxy radical, HO•2, or diatomic oxygen, O2). Nausea, dyspnea, and headache are some of the symptoms of short-term nitrogen dioxide exposure. Immune and respiratory function could be harmed in the long run.

Conclusion 

Hence, Nitrogen monoxide is a colorless gaseous compound also known as nitric oxide and has the formula NO. It is one of the most common nitrogen oxides. Nitric oxide is a free radical, meaning it possesses an unpaired electron, which is sometimes indicated in its chemical formula NO. The class of heteronuclear diatomic molecules, a type of molecule whose study led to the development of early modern chemical bonding theories. It functions as a signal in the cardiovascular and neurological systems, and it is crucial for blood pressure management. White blood cells can also produce huge levels of NO. In the chemical industry, NO is an enormously essential intermediate.