Ammonia (NH3): Physicochemical properties

Release time:

2018-11-05

Ammonia (NH3): Physicochemical properties

1. At normal temperature and pressure, ammonia is a colorless, toxic gas with a characteristic pungent odor and is lighter than air. Ammonia is stable at room temperature, but it decomposes into hydrogen and nitrogen at high temperatures. It decomposes at 450-500℃ under one atmospheric pressure. If iron, nickel or other catalysts are present, it can decompose at 300℃. 2NH3---------3H2+N2.

2. The molecular weight of ammonia is 17.031. Its boiling point is -33.35℃ under standard conditions, critical temperature is 132.4℃, critical pressure is 1127 Kpa, critical specific volume is 4.130 L/kg, and freezing point under standard conditions is -77.7℃.

3. Ammonia is combustible in air, but it is generally difficult to ignite. If it is continuously exposed to a fire source, it will burn, and sometimes it can also cause explosions. If there are oils or other combustible substances, it is easier to ignite. When burning in oxygen, it produces a yellow flame and generates nitrogen and water. 4NH3+3O2----------2N2+6H2O.

4. Ammonia can also explode in nitrous oxide, with an explosion concentration limit of 2.2%-72%.

5. Ammonia is slightly soluble in methanol, ethanol, dichloromethane and ether.

6. The latent heat of vaporization of liquid ammonia is very large, second only to water, being 301.8 Cal/g at 0℃. Therefore, it has properties similar to water and can dissolve many substances. Its solution also exhibits many properties similar to aqueous solutions. Liquid ammonia can dissolve ammonium salts, various metal salts, hydrochloric acid, iodides, phenols and amines.

7. Ammonia is toxic. The maximum allowable concentration is 25 ppm (18 mg/m³). Ammonia is mainly absorbed through the respiratory tract, but it can also be absorbed through the skin. Ammonia is dangerous when mixed with certain substances.

Key words:

Previous Page:

Physicochemical properties of oxygen (O2)

Next page:

Physical properties of hydrogen (H2)

Related Support

Methods for Selecting a Nitrogen Generator

Pressure Swing Adsorption (PSA) nitrogen generators, using carbon molecular sieve as adsorbent, represent an advanced gas separation technology irreplaceable in on-site gas supply worldwide. They are widely used across various industries. With hundreds of nitrogen generation companies in existence, selecting a high-performance nitrogen generator is a primary challenge for many customers. While nitrogen generator selection involves numerous considerations, careful analysis, comparison, and focus on key aspects will lead to satisfactory results.

2018-11-05

How to extend the service life of a nitrogen generator

Many people have used nitrogen generators, but not everyone knows how to extend their lifespan. Here's a simple operating procedure.

2018-11-05

What are the benefits of using a nitrogen generator to fill food packaging?

With the continuous improvement of people's living standards, the demand for food quality that sustains their lives is also increasing day by day. Everyone hopes that the food they eat every day is fresh and delicious! However, some food packaging on the market is always unsatisfactory. Now, a new type of nitrogen packaging meets this need.

2018-11-05

Application of PSA pressure swing adsorption nitrogen generators in SMT welding

In recent years, with the increasing demand for the quality of welding products and the increasingly stringent national environmental protection requirements, lead-free welding has become widely popular. Inert nitrogen welding has been favored for its ability to improve product quality. Although the purchase of nitrogen atmosphere requires a certain amount of investment, it is much lower than the cost of environmental protection and rework due to welding defects. Therefore, the role of inert nitrogen atmosphere in SMT welding is increasingly valued and will gradually be accepted and widely used. However, the cost of using nitrogen depends largely on the flow rate, operating hours, reflow oven structure, and production process, and the choice of nitrogen source is even more important.

2018-11-05

Application of nitrogen in vacuum heat treatment

Vacuum heat treatment (shell and tube heat exchanger) is a relatively advanced heat treatment method adopted both domestically and internationally. Nitrogen is often indispensable in vacuum heat treatment.

2018-11-05