You must have heard a lot about acids and bases in your chemistry classes. They are available in laborites to perform different reactions. However, they are also readily available in our daily life. Such examples of acids include citric acids and lactic acids in lemon and yogurt. Bases are available in your bathrooms, like soaps, detergents, and bleach, etc. We can also say that anything you eat or drink in your daily routine is an acid or base except water, which is considered neutral.
Acids and bases came into existence after the success of three theories. These theories are Arrhenius, Bronsted, and Lewis. Acids and bases are two categories of corrosive substances.
What is an Acid?
An acid is a substance that ionizes to produce hydrogen ions when dissolved in water. Acids conduct electricity because they have free moving Ions. They have a sour taste and have a PH value of less than 7. Acids react with metals to form salt and hydrogen. They also react with carbonates or Hydrogen carbonates from carbon dioxide gas, salt, and water.
When acids react with a metal oxide or metal hydroxide the end products of the reaction include salt and water. Acid doesn’t show its acidic properties unless it is dissolved in water because water is required for the formation of hydrogen ions. A strong acid is the one that completely ionizes in water whereas a weak acid partially ionizes in water. A strong acid reacts more vigorously than weak acids in the same reaction.
The concentration of acid refers to the amount of acid per unit of volume of a solution. The concentration of acid and strength of acid are two different things. Acids have many uses. Acids like phosphoric acid and ethanoic acid are used in the flavoring of food. Ethanoic acid is also used as a food preservative.
Acids are also used in car batteries. However, acids lead to acid rain which destroys crops and building and harm marine life.
All acids contain hydrogen, but not all compounds that contain hydrogen are acids. For example, both ammonia and methane contain hydrogen but they are not acids. Because they do not produce hydrogen ions in water.
Carbonated drinks are slightly acidic due to the carbon dioxide dissolved in them. The carbon dioxide is added to give the fizz to the drinks. Fizz is gas that readily moves and escapes from the drink.
What is the base?
Bases are oxides or hydroxides of metals. The bases which are soluble in water are called alkalis. Alkalis produce hydroxide ions when dissolved in water. They have a bitter taste and have a ph. less than 7. Alkalis conduct electricity and they turn red litmus paper blue. They react with acids to form salt and water only and this reaction is known as neutralization.
Alkalis react with ammonium compound on heating to give salt, water, and ammonium gas. They react with a solution of metal salt to give another metal salt and a metal hydroxide. A strong alkali ionizes completely in water to form hydroxide ions whereas a weak alkali partially ionizes.
Alkalis are quite useful as alkalis like magnesium oxide are used as an antacid to relieve gastric pains. Sodium hydroxide and potassium hydroxide are used in the manufacture of soap. And calcium hydroxide or Cailum oxide is used in the liming of soil.
We can differ bases from each other in 5 categories, strong base, weak base, neutral base, super base, and solid base. All alkalis are bases but not all bases are alkalis.
Importance of pH acid and base!
Our blood is slightly alkaline. Acid has a pH of about 7.4. when a person is given an injection, the substance being injected must have a pH of almost 7.4. if the pH of blood is changed by 1 unit, say to 8.3, the person would die!
What are the differences between acid and base?
Let’s look deeper into the differences between these two. What are some strong categories on which we can differentiate acids from bases?
· Definition by Arrhenius:
According to Arrhenius’s theory, acids when dissolved in water increases the number of hydrogen ions in the solution. And bases when dissolved in water will elevate the number of hydroxide ions in the solution.
· Definition by Bronstad:
According to Bronstad’s theory, acids are donors of protons and bases are acceptors of the proton.
· Definition by Lewis
According to Lewis’s theory, Ions that give a pair of electrons and own a lone pair of electrons are termed ‘Lewis’s base’. And Ions that receive the pair of electrons and own vacant orbitals are termed ‘Lewis’s acid’.
Some examples of acids are acetic acid (CH3COOH) and sulphuric acid (H2SO4). Sodium hydroxide (NaOH) and ammonia are examples of bases.
· Ph value
Acids have a Ph value less than 7 and bases have a Ph value more than 7.
· Phenolphthalein test
Acids show a colorless solution when dissolved in Phenolphthalein whereas bases make this solution pink in color.
· Chemical formula
The chemical formula of acids starts with H and the chemical formula of bases ends with OH. For example, hydrochloric acid has a chemical formula HCL and sodium hydroxide(base) has a chemical formula NaOH.
· Litmus paper test
Acids turn blue litmus paper into red and bases turn red litmus paper into the blue.
The strength of acids and bases depends on the concentration of the hydronium ions.
Acids exist in solids, liquids, and gases. Their existence depends upon the temperature of the environment around them. Whereas bases exist mostly in a slippery and solid-state. Ammonia is the only exception of the base that occurs in gaseous form. Bases taste bitter.
Acids releases hydrogen ions (H+) when dissolved in water, whereas bases release hydroxide ions (OH-) when dissolving in water.
Some general examples of acids found around us are sulphuric acid, acetic acid, citric acid, ascorbic acid, and lactic acids. Some common examples of bases around us are sodium hydroxide, calcium carbonate, potassium oxide, and ammonia.
As a conclusion to this blog, we will say that acids and bases are equally important for us. they play a major role in our lives today. Whether it’s a task of digesting food or removing bad stains from the bathroom wall, they come to the rescue. Acid and base together work to maintain the normal Ph for the body, that is 7. Bases within the body help to maintain its alkalinity. When acidic food enters the stomach, the body launches a buffering system to neutralize these positive ions.
Acid and bases are found in our body, in the environment around us, and in the food we eat. It plays an equally important role in the manufacturing of chemicals and pharmaceutical companies. Hence, acids and bases are not only limited to your chemistry lab.
Have some fun doing this experiment after you finish reading this blog. Rub some lemon juice onto an old copper coin, the citric acid will react with copper (II)oxide on the coin to give you a bright shiny coin.
Also read: Difference between orbit and orbital.