Acid vs. Base: What’s the Difference

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Jackson Roy

Acids and bases are everywhere, and we use and observe them in our daily life; however, these terms are usually used in chemistry. Acids and bases are entirely different depending on their properties and reactions. But the significant difference between acid and base is their pH level. Acids have a pH level of less than 7, while bases have a pH higher than 7. These are also different based on how they ionize in water.

Acids are the chemicals that elevate H+ in water, and bases are chemicals that elevate H- in water. They have different chemical and physical properties. Various theories like Bronsted, Arrhenius, and Lewis explain other properties of acids and bases. Moreover, some substances act like both acids and bases; these substances are called amphoteric.

What is Acid?


Acids are chemicals that can accept electrons and donate protons or hydrogen ions. The acidity of an acid depends upon the number of hydrogen ions. The higher the concentration of hydrogen ions produced by acid higher will be its acidity. And due to an increase in acidity, the pH of the solution will decrease.

Theories about Acids

Different theories explain acids’ properties, reactions, solubility, and nature. These theories include the following:

  • Arrhenius Acid
  • Bronsted-Lowry Acid
  • Lewis Acid

Physical Properties of Acid

There are the following physical properties of an acid:

  • Acids are primarily sour; the most common horrible taste acid is vinegar.
  • Most acids are readily soluble in water. However, there are some exceptions.
  • It turns the blue litmus paper to red.
  • Acids have a pH lower than seven; the lower the pH is more vital the acid will be.
  • Acids produce carbon dioxide and water when reacting with carbonates.

Chemical Properties of Acid

  • Aqueous solutions of acids can conduct electricity. They ionize in water entirely and act as a conductor. Some acids do not completely ionize in water and are weak electrolytes.
  • Acids yield hydrogen gas when they react with metals.
  • Acids react with a base to produce salt and water.

Examples of Acids

There are the following examples of acids:

  • Hydrochloric acid
  • Hydrofluoric acid
  • Acetic acid( vinegar)
  • Stomach acid
  • Citric acid

Advantages of Acids

  • Acids are used to enhance the taste of the food.
  • Acids are used to store food.
  • Acids are used in the cleaning of metal.
  • Acid plays an important role in the fertilizers industry.
  • Acids are used to neutralize the basic soil.

Disadvantages of Acids

  • Acids can burn the skin and clothes.
  • Acids cannot be stored in metal containers as they cause corrosion in metal.
  • Acids can cause allergy and irritation.
  • An increase in the concentration of acid in the stomach can cause acidity.

Read More: Brown Eggs vs. White Eggs – What’s The Difference

What is a Base?


Bases are defined as chemicals that produce negative hydroxide ions when they get dissolved in water. The basicity of the base depends upon the concentration of hydroxyl ions. Bases have a direct relationship with hydroxyl ions. The pH of bases is above 7.

Theories about Base

Different theories explain bases’ properties, reactions, solubility, and nature. These theories include the following:

  • Arrhenius Base
  • Bronsted-Lowry Base
  • Lewis Base

Physical Properties of Base

  • Bases usually have a bitter taste.
  • They turn the red litmus paper to blue.
  • They have a pH higher than seven.
  • Bases are slippery to the touch.
  • They are also conductors of electricity.

Chemical Properties of Base

  • Bases react with acid to give salt and water through neutralization.
  • Bases react with ammonium ions to produce ammonia.
  • Bases are used to neutralize the acidic soil.
  • Strong alkalis or bases are highly corrosive as compared to weak alkalies.

Advantages of bases

  • Bases are used as a reagent in laboratories, such as sodium hydroxide.
  • Bases play an essential role in the production of soap and detergents.
  • Base like sodium hydroxide is used in refining petroleum.
  • Bases are also used for making medicines and bleaching agents.

Disadvantages of Base

  • Bases are harmful chemicals and can cause severe damage if not handled properly.
  • It can cause rash, irritation, and allergy to the skin.
  • Splash over the eyes can cause permanent blindness.
  • If the fumes of bases are inhaled for a long time, it can cause respiratory disorders.

Comparison Chart Between Acid and Base

Basis for Comparison Acids Base
Arrhenius concept Acid is a chemical that gives hydrogen ions when dissolved in water. The base is a chemical that gives hydroxide ions when dissolved in water.
Bronsted-Lowry concept Acid is considered a proton donor. The base is considered a proton acceptor
Lewis concept Acid can accept electrons. Bases can donate electrons.
pH value Acids have a pH value of less than 7. While bases have a value of more than 7.
Litmus paper It turns blue litmus paper into red It turns red litmus paper into blue
Characteristics Depending on the temperature, acids can be solid, liquid, or gas. Except for ammonia bases are usually solid.
Physical nature the physical nature of acid is corrosive. The physical nature of the base is slippery
strength. The strength of an acid depends upon the concentration of hydrogen ions. The strength of the base depends upon the concentration of hydroxyl ions.
Taste They are sour. They are bitter.
Examples Hydrochloric acid

Sulphuric acid

Nitric acid

Sodium hydroxide

Potassium hydroxide

Ammonium hydroxide


Acids and bases play an essential role in our daily life. Almost every biological chemical process is related to acid-base mechanism and balance. Although acids and bases are harmful, they are also essential for the body’s normal functioning because most of our body’s enzymes work in a specific acidic or basic environment.