Have you ever wondered why everything has a different taste? Why is it the sour taste of lemon but sweet mango? It is because of the different percentages of acid, base and salts in their chemical composition. Acid, base and salts are the concepts that affect our daily life, and it's easy to identify the taste differences in them. Acid is sour in taste, and it turns the blue litmus to red, whereas the base is bitter and turns the red litmus to blue. Have you ever noticed that the curry stain on the white cloth will appear to be reddish-brown in colour when soap is scrubbed on it (basic in nature)? It turns the cloth yellow in colour again when washed with plenty of water. Is it interesting? Keep reading to know more about the definition and properties and understand the concepts from scratch.
Numerous acids and bases are found naturally, such as citric acid in fruits like lemon, and orange, tartaric acid in tamarind, lactic acid in milk, etc. Similarly, bases can also be found naturally, such as lime water. We use these bases in our everyday life, such as vinegar in the kitchen, baking soda for cooking, washing etc. Several acids are not meant for domestic use; instead, they are used in laboratories and industries. For example, acids such as HCl, H2SO4 etc., and bases such as KOH, NaOH etc. When the acid and base are mixed in the right proportion, they form salt and water. Some of the naturally occurring salts such as KCl, NaCl etc. The following are the definition of the acid, base and salts:
The term acid has been derived from the Latin word "acidus", meaning sour. It is defined as the substance whose solution is sour in taste, turns blue litmus to red and accepts electron pairs. When they react with metal, they release dehydrogenase. According to the Arrhenius hypothesis, acids are compounds that dissociate in water to create hydrogen ions H + (aq), while bases produce hydroxyl ions OH –. (aq)
It is a substance whose aqueous solution taste bitter and feel soapy; it turns red litmus to blue and donates pair of electron. It becomes less basic when it is mixed with acid. According to Arius, bases are substances that dissolve in water and release hydroxide ions in solutions. Common bases include sodium bicarbonate, mainly used in cooking and household bleach, calcium hydroxide etc.
It's an ionic compound, neutral, acidic and base in nature. It's an aqueous solution and doesn't affect litmus. It is formed through the neutralisation reaction by the combination of acid and base. Some common examples of Salts are sodium chloride, nitrate, barium sulphate and others.
The following are the physical properties of acid, base and salts:
The following are the chemical properties of the acid:
1. Reaction with Active Metals
When acid reacts with the active metals, it generally displaces the hydrogen from acids, leading to the evolution of the hydrogen gas. The metals react with the residual acids to form a salt.
Metal+Diluteacid→Metalsalt+Hydrogen
Example:
Zn+H2SO4→ZnSO4 +H2↑
Fe+H2SO4→FeSO4+H2↑
Less reactive metals such as copper and silver don’t react with the dilute acids.
As a result, not all metals react with the same acid in the same way. Highly active metals in the activity range above hydrogen react vigorously with dilute acids to liberate hydrogen gas, whereas less active metals react less aggressively with dilute acids.
2. Reaction of Metal Carbonates/Bicarbonates with Acid
When dilute acid reacts with metal carbonate, it generates salt, water and carbon dioxide.
Metal carbonates/bicarbonates+Acid→Salt+water+carbondioxide
Example:
Na2CO3 +H2SO4 →Na2SO4+H2O+CO2↑
NaHCO3 +HCl→NaCl+H2O+CO2↑
3. Reaction of Acid with Base
When acid reacts with the base, it generates salts and water, and this reaction is called neutralisation.
Acid+Base→Salt+Water
Example:
When hydrochloric acid combines with sodium hydroxide solutions, sodium chloride and water are formed due to a neutralisation process.
NaOH+HCl→NaCl+H2O
4. Reaction of Metal Oxide with Acid
When acid reacts with metal oxide, it forms salts and water; therefore, it is a kind of neutralisation process.
MetalOxide+Acid→Salt+Water
Example:
A black metallic oxide combined (copper oxide) with hydrochloric acid forms blue-green copper chloride and water.
CuO+2HCl→CuCl2+H2O
The following are the chemical properties of the base:
Alkali: It is a base that dissolves in water. It is a chemical that produces hydroxyl ions (OH–) as the sole negative charge ions when dissolved in water. Alkalis are not bases that are not soluble in water. As a result, all bases are alkalis, but not all alkalis are bases.
1. Reaction with Acid
The bases combine with the acid to form salt and water. It is called neutralisation.
Base+Acid→Salt+Water
Example:
NaOH+HCl→NaCl+H2O
2. Reaction of Alkalis with Metal Oxide
Bases such as sodium hydroxide and potassium react with active metals such as aluminium and zinc and evolve hydrogen gas.
Example:
Zn+2NaOH→Na2ZnO2+H2
2Al+2NaOH+2H2O→2NaAlO2+3H2
3. Reaction of Base with Non-Metallic Oxide
When the base reacts with non-metallic oxide, it produces salt and water.
Example:
2NaOH(aq)+CO2(g)→Na2CO3(aq)+H2O(l)
Ca(OH)2(s)+SO2(g) →CaSO3(aq)+H2O(l)
The following is the list of the similarities between the two:
Acid, base and salts are important topics. It will not only help you to score good marks in your academics but also help you to crack the competitive exams. Therefore, it is essential to understand the topic from the basics. You can also join our Chemistry class to develop a strong foundational base on the subject. The following are the additional key benefits you can avail of:
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