Chemical Industry's Impact on Food, Health, and Environment

The Chemical Industry's Role in Food Production

Food doesn't come directly from nature; it requires the chemical industry for production, preservation, and preparation. Production involves fertilizers, pesticides, and fuel for machinery. Conditioning includes packaging, refrigeration materials, preservatives, and sterilization processes for microorganism control. Preparation uses fuel, containers, and spices for flavor and easier digestion. Most materials in our homes are not in their natural state but come from the chemical industry.

Improved Nutrition and Health

Life expectancy in Europe has doubled in the last 200 years due to improved nutrition, hygiene, and medicine. Water chlorination uses chlorine to prevent diseases like cholera, typhoid, and dysentery. Antibiotics control bacterial infections. We can improve our health by using drugs responsibly, improving farming methods to reduce pesticide and fertilizer use, adapting our consumption habits to locally produced food with less environmental impact, and reducing our dependence on oil.

Properties of Substances

Each pure substance has specific properties that distinguish it from others. Examples include:

• Density: the mass contained in a unit volume.
• Temperature change of state: the temperature at which a solid becomes a liquid (melting point) or a liquid boils.
• Hardness: resistance to being scratched.
• Solubility: the ability to mix with other liquids.

Physical and Chemical Changes

Physical changes are reversible, where substances retain their identity. Chemical changes are more profound transformations, creating entirely new substances. The initial substances are called reactants, and the new ones are products. Many daily processes are chemical changes, such as the oxidation of iron, newsprint yellowing, meat turning white when cooked, and wood combustion. Most biological processes are also chemical reactions.

Molecular Structure and Chemical Reactions

A substance's properties depend on its molecular structure. For example, butane molecules contain four carbon and ten hydrogen atoms. In the presence of oxygen and high temperatures, collisions break these molecules. The released hydrogen atoms bind to oxygen atoms, forming water molecules.

Chemical Equations and Energy

Changes are written using equations with molecular formulas. An arrow indicates the direction of change in a chemical reaction. Atoms are conserved in chemical reactions. Numbers are placed outside formulas to achieve the same number of atoms in reactants and products. Chemical energy is stored in substances. Exothermic reactions release chemical energy, while endothermic reactions increase it. Stored chemical energy is like potential energy, which transforms into kinetic energy, increasing temperature when molecules break free.