Base

A base is a compound that neutralises acid by reacting with hydrogen ions. The majority of bases are minerals that produce water and salts when they combine with acids. Metal oxides, hydroxides, and carbonates are examples of bases. Some of the most common bases are calcium carbonate, potassium oxide, and sodium hydroxide. The soluble bases are also known as the alkalis. A strong base is entirely dissociated in an aqueous solution. In water, these compounds ionise, yielding one or more hydroxide ions (OH-) per base molecule. A weak base only partially dissociates into its ions. A good example of a weak base is ammonia. Stable compounds are formed when strong bases react with strong acids.

Apart from academics, we also encounter the bases in our daily life. We use bases in our daily activities such as toothpaste, soap, baking soda, cleansing agents, antacids, etc.

What are bases?

The base or alkaline is the compound that accepts protons, denotes electrons, and can release hydroxide ions in a liquid solution. The basic or alkali compounds are bitter and have a slippery texture. Some of the notable features of the bases include:-

• They turn red litmus paper to blue
• React with acidic substance to make salts
• Accept proton or H+ from the suitable donor 
• Hold the hydroxide ions, which are completely or partially displaceable. 

Bases reduce the hydrogen ion when dissolved in a liquid by changing the auto-ionisation equilibrium of the liquid. So, the pH of water is effectively increased above the 7.0 mark when bases are dissolved in it.

Chemical properties of bases

Some common chemical properties of the bases are given below:-

• Bases turn red litmus paper to blue.
• Bitter in taste.
• When reacted with the acids, bases lose their basicity.
• When reacted with the acids, the base leaves salt and water. This reaction is known as neutralisation. 
• Bases are good conductors of electricity in the molten state.
• Bases have a soapy and slippery texture.
• Bases like potassium hydroxide, sodium hydroxide, etc., are used as electrolytes.
• The pH range of bases is between 8-14.
• Ammonium and alkali salts make ammonia.
• When a metal reacts with the base, it releases hydrogen gas. 

Classifications of the bases

• Strong base – This compound can eliminate protons from a very weak acid or in an aqueous solution. It dissociates into its ions. Some common examples are sodium hydroxide (NaOH), potassium hydroxide (KOH), etc. 
• Weak base – Weak base is a chemical compound that does not completely dissolve in water or aqueous solution. Some common examples are ammonia water, and pyridine (C5H5N).
• Superbase – A superbase is an exceedingly strong base. It’s a substance with a strong affinity for protons. The strongest base in water (aqueous) solutions is the hydrogen ion, but superbases are more powerful than aqueous bases. Some of the examples are ortho-diethynylbenzene dianion and sodium hydride (NaH).
• Neutral base – The neutral base is the substance whose PH level is exactly 7. Examples of neutral bases are water and human blood. 
• Solid base – The bases available in solid form are known as solid bases. Examples are, Al₂O₃, CaO, MgO

Bases based on the concentration 

On the basis of concentration bases are classified as:-

• Dilute base: The quality of base decreases with the addition of an excessive quantity of water, the base in which water concentration is more, and the base is less known as the dilute base. The most common example of a dilute base is dilute NaOH, dilute KOH, etc. 
• Concentrated base: The quality of base increases with the reduction of the quantity of water, the base in which the base is more and water is less is known as the concentrated base. The most common example of a concentrated base is NaOH. 

Uses of Base 

The bases are used in numerous industries and household works. Some most common uses of the bases are listed below –

• In the manufacturing of rayon, toothpaste, soaps, paper, etc.
• Bases are used in the baking.
• Bleaching powder and used for cleaning purposes. 
• Bases are used in the cleaning of sulphur dioxide.
• It is a whitewash. 
• Bases are widely used in the detergent manufacturing sector 
• A certain class of NH₄OH is used to remove grease marks from clothes 
• Bases are used in the production of chalk

Conclusion

This chapter looked into the definition, types, and properties of base. We learned that base is a compound that neutralises acid by reacting with hydrogen ions. We have learned about a base’s various physical and chemical properties, such as turning red litmus paper to blue, bitter in taste, reacting with the acids, losing their basicity, and good conductors of electricity in the molten state. We have also learned about the uses of bases in daily life and Industry.