Grado 9

Grado 9Ácidos, Bases y Sales


Uses of acids, bases and salts in daily life


Acids, bases, and salts are fundamental chemical compounds that we encounter in our daily lives, often without realizing it. Each has its own unique properties and applications that are integral to various aspects of modern life. In this detailed lesson, we will explore how these compounds are used in homes, industries, and nature.

Acids in everyday life

Acids are substances that taste sour, can turn blue litmus paper red, and have a pH value less than 7. They are known for their reactivity with metals, carbonates, and bases.

Household uses of acid

  • Vinegar ( CH 3 COOH ): Acetic acid is the main component of vinegar and is widely used in cooking due to its sour taste. It helps in making pickles and is an effective cleaning agent due to its ability to dissolve mineral deposits, dirt and grime.
  • Citrus fruits: Oranges, lemons and other citrus fruits contain citric acid. Citric acid is used as a natural preservative and flavoring agent in beverages. It also has antioxidant properties.
  • Vitamin C ( C 6 H 8 O 6 ): Ascorbic acid, better known as vitamin C, is essential for human nutrition and is found in fruits such as oranges and strawberries. It strengthens the immune system and helps repair tissues.

Industrial uses of acids

  • Sulfuric acid ( H 2 SO 4: A key chemical in industry, it is used in the manufacture of fertilizers, battery acid in cars, and in the production of cleaning agents.
  • Hydrochloric acid ( HCl ): It is used in the steel industry to remove rust or iron oxide scale from iron or steel before further processing.

Visual example

Acid

Basis in daily life

Bases are substances that are slippery, can turn red litmus paper blue, and have a pH value greater than 7. They are known to react with acids to form salt and water.

Household uses of bases

  • Baking soda ( NaHCO 3 ): Also known as sodium bicarbonate, it is used as a leavening agent in baking. It reacts with the acid in the batter to produce carbon dioxide gas, which helps the dough to rise.
  • Ammonia solution ( NH 3 ): This is commonly used as a cleaning agent because of its ability to remove dirt and stains without leaving any residue. It is often found in window cleaners.
  • Milk of magnesia ( Mg(OH) 2 ): Used as an antacid to neutralize stomach acid, relieving indigestion and heartburn.

Industrial use of bases

  • Sodium hydroxide ( NaOH ): Also known as caustic soda, it is important in the manufacture of soaps and detergents. It is also used to process petroleum and in water treatment.
  • Calcium hydroxide ( Ca(OH) 2 ): It is used in the construction industry to make cement and mortar. It is also used in the purification of sugar.

Visual example

Base

Salt in everyday life

Salts are ionic compounds that form from the neutralization reaction of acids and bases. They usually consist of positive ions from the base and negative ions from the acid.

Household uses of salt

  • Table salt ( NaCl ): Used as a seasoning and preservative in foods. Salt also plays an important role in body functions such as nerve transmission and muscle contraction.
  • Baking soda and baking powder: In addition to its role as an alkali, baking soda forms part of baking powder along with being a weak acid that aids in baking by releasing carbon dioxide gas.
  • Epsom salt ( MgSO 4 ): It is used in baths to relax sore muscles and as a laxative to relieve constipation.

Industrial uses of salts

  • Ammonium nitrate ( NH 4 NO 3): It is mainly used in agriculture as a high nitrogen fertilizer. It is also used in making explosives.
  • Sodium carbonate ( Na 2 CO 3: Also known as soda ash, it is used in glass making, paper production, and detergents.

Visual example

Salt

Neutralization reactions in everyday life

Acids and bases can neutralize each other to form salt and water. This neutralization reaction is fundamental in a variety of everyday processes.

Examples of neutralization

  • Antacids: Medicines such as Tums or Rolaids, which usually contain compounds such as calcium carbonate, neutralize stomach acid, providing relief from indigestion.
  • Agriculture: Lime, or calcium hydroxide, is added to acidic soil to neutralize it, thereby improving soil fertility.

Visual example for neutralization

HCl + NaOH → NaCl + H₂O fail

Conclusion

Understanding the role of acids, bases and salts in daily life not only broadens our view of how chemistry relates to everyday activities, but also emphasizes their importance in household and industrial applications. By taking advantage of their properties and reactions, we can maintain health, improve processes and enhance quality of life. Chemistry continues to play a vital role in innovation and development, providing solutions to everyday challenges.


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