Industrial Chemical Processes and Material Properties

Ammonia

Ammonia is a colorless gas with a characteristic, suffocating odor. It is prepared from hydrogen and nitrogen using the method introduced by Haber and Bosch in Germany, known as the Haber synthesis. The stages of this method are:

• Preparation of synthesis gas: Processes to obtain the hydrogen and nitrogen needed for the reaction.
• Catalytic synthesis: The gases are contacted with a catalyst in a reactor at temperatures ranging from 400 to 600 °C and pressures from 200 to 1000 atm.
• Separation of ammonia: The mixture from the reactor is cooled until the ammonia liquefies and separates from the gas stream; the remaining nitrogen and hydrogen are recycled.

Ammonia is used as a cleaning agent due to its great solvent power, as a refrigerant in cooling systems, and as a feedstock for the production of nitrogen fertilizers, synthetic fibers, plastics, adhesives, dyes, explosives, pharmaceutical products, and nitric acid.

Solvay Process for Sodium Carbonate

The Solvay method for the industrial manufacture of sodium carbonate, in use since 1861, consists of a succession of chemical reactions that start from readily available raw materials such as common salt, ammonia, and calcium carbonate.

Greenhouse Effect

The greenhouse effect consists of an increase in the temperature of the Earth's surface as a result of the growing accumulation of gases in the atmosphere.

Physical Properties

Physical properties are those present in matter without changing its composition, such as hardness, solubility, and color.

Chemical Properties

Chemical properties refer to changes in matter when it undergoes chemical reactions, such as combustion.

Extensive Properties

Extensive properties are those that depend on the quantity of matter present, including volume and internal energy. For example, internal energy is the sum of the kinetic and potential energy of each particle.

Intensive Properties

Intensive properties are those that do not depend on the amount of matter present. For example, the melting point of ice at normal pressure is 0 °C, regardless of whether the sample is an ice cube or an iceberg.