Question

Identify and describe the characteristic properties of five common acids used in industry. Give some examples of the typical uses of each.

Short answer

Common acids in industry include sulfuric acid (H2SO4), hydrochloric acid (HCl), nitric acid (HNO3), acetic acid (CH3COOH), and phosphoric acid (H3PO4).

Step-by-step solution

Identify Sulfuric Acid

Sulfuric acid (H2SO4) is a highly corrosive strong mineral acid. It is commonly used in the production of fertilizers, in petroleum refining, and in wastewater processing.

Identify Hydrochloric Acid

Hydrochloric acid (HCl) is a strong acidic solution of the gas hydrogen chloride in water. It is used in large-scale production of PVC plastic, as a cleaning agent in metal processing, and for pH control and neutralization.

Identify Nitric Acid

Nitric acid (HNO3) is a highly toxic and corrosive strong acid. It is used in the manufacture of explosives, fertilizers, and in the nitration of organic compounds.

Identify Acetic Acid

Acetic acid (CH3COOH) is a weak acid but highly corrosive in concentrated form. It is commonly used in the production of vinegar, as a solvent for chemical reactions, and in the manufacture of synthetic fibers and plastics.

Identify Phosphoric Acid

Phosphoric acid (H3PO4) is a moderately strong acid. It is commonly used in the food and beverage industry to acidify foods and beverages, in the manufacture of phosphate fertilizers, and in the cleaning and refining of metals.

Key concepts

Sulfuric Acid

Sulfuric acid (H2SO4) is a highly corrosive strong mineral acid.
It is an essential chemical in many industries due to its versatile properties. This acid has a high boiling point and is very hygroscopic, meaning it can absorb water from the air.

Sulfuric acid is commonly used in:

• Production of fertilizers: It helps in producing phosphoric acid and ammonium sulfate, which are key components in fertilizers.
• Petroleum refining: It is used in the alkylation process to enhance the octane number of gasoline.
• Wastewater processing: It helps in neutralizing the wastewater to remove harmful contaminants.
• Manufacturing chemicals: It plays a role in producing various chemicals like hydrochloric acid and nitric acid.

Despite its many uses, it is highly dangerous and can cause severe burns, so proper precautions are necessary.

Hydrochloric Acid

Hydrochloric acid (HCl) is a strong acidic solution of hydrogen chloride gas in water.
This colorless acid is known for its pungent smell and highly corrosive nature. It is widely used in different industrial applications.

Typical uses include:

• Large-scale production of PVC (polyvinyl chloride) plastic: HCl is used in the chemical process that creates this commonly used plastic.
• Metal processing: It acts as a cleaning agent, often referred to as 'pickling', to remove rust and other impurities from the metal surfaces.
• pH control and neutralization: It is used in various industries to control the acidity or alkalinity of solutions.

Care must be taken when handling hydrochloric acid because it can cause severe chemical burns and irritate the respiratory system.

Nitric Acid

Nitric acid (HNO3) is a highly toxic and corrosive strong acid.
This acid is an important industrial chemical known for its ability to dissolve most metals and its powerful oxidizing properties.

Common applications include:

• Manufacture of explosives: It is a key component in the production of nitroglycerin and trinitrotoluene (TNT).
• Fertilizers: It is used to produce ammonium nitrate, a major nitrogenous fertilizer.
• Nitration of organic compounds: It plays a role in introducing nitro groups into organic molecules, which is essential in creating dyes, pharmaceuticals, and other chemicals.

Due to its reactive nature, nitric acid must be handled with extreme caution, using appropriate personal protective equipment.

Acetic Acid

Acetic acid (CH3COOH) is a weak acid but highly corrosive in concentrated forms.
This organic acid is colorless, with a distinct sour taste and pungent smell, commonly associated with vinegar.

It's used extensively in:

• Production of vinegar: Diluted acetic acid gives vinegar its characteristic taste and acidity.
• Chemical reactions: It serves as a solvent and reagent in chemical synthesis.
• Manufacture of synthetic fibers and plastics: Acetic acid is a precursor in the production of vinyl acetate monomer (VAM) and cellulose acetate.

Though less hazardous than some stronger acids, concentrated acetic acid can still cause severe chemical burns and must be handled with care.

Phosphoric Acid

Phosphoric acid (H3PO4) is a moderately strong acid that appears as a clear, colorless liquid.
It is valued in various industries for its phosphate content and acidifying properties.

Its common uses include:

• Food and beverage industry: It is used to acidify foods and beverages like colas and jams, providing them with a tangy flavor.
• Manufacture of phosphate fertilizers: It serves as a key ingredient in producing fertilizers that promote healthy plant growth.
• Cleaning and refining of metals: It cleans and treats metal surfaces, enhancing their resistance to rust and corrosion.

Handling phosphoric acid typically requires safety measures, although it is considered less dangerous compared to stronger acids like sulfuric or hydrochloric acid.