Acids and Alkalis

Introduction to Acids and Alkalis

  • Acids are substances that can donate a proton (H+ ion) when dissolved in water.
  • Examples of commonly known acids include sulphuric acid (H2SO4), hydrochloric acid (HCl) and nitric acid (HNO3).
  • Alkalis are substances that can accept a proton or donate an electron pair in reaction.
  • Sodium hydroxide (NaOH), potassium hydroxide (KOH) and calcium hydroxide (Ca(OH)2) are examples of alkalis.
  • Acids and alkalis can neutralise each other in what is known as a neutralisation reaction.

Properties of Acids and Alkalis

  • Acids have a pH less than 7 while alkalis have a pH greater than 7.
  • Acid and alkaline solutions can conduct electricity due to the presence of ions.
  • Acids taste sour and alkalis taste bitter.
  • Both acids and alkalis can cause burns and should not come into contact with skin.

Reactions involving Acids and Alkalis

  • When acids react with metals, a salt and hydrogen gas is produced.
  • Acids react with carbonates to produce a salt, water and carbon dioxide.
  • Alkalis can react with nonmetals to produce a type of salt.
  • Acids and alkalis undergo a neutralisation reaction to produce a salt and water.

Uses of Acids and Alkalis

  • Acids like citric acid and ascorbic acid are used in the food industry to keep food fresh and add a sour taste.
  • Sulphuric acid is used in the manufacture of detergents, dyes and plastics.
  • Alkalis like sodium hydroxide are used in soap making and in the production of paper.
  • Calcium hydroxide is used in agriculture to neutralise acidic soils.

Safety Precautions when Handling Acids and Alkalis

  • Due to their corrosive nature, acids and alkalis must be handled with care.
  • It’s crucial to wear protective eyewear, gloves and lab coats when dealing with these substances.
  • Spillage should be neutralised immediately to prevent burns or further harm.

Understanding the characteristics and properties of acids and alkalis is vital when reviewing inorganic chemistry. By acknowledging their reactivity and uses, we can appreciate their importance in daily life and in various fields of science.