In the previous lessons, we learned about the basic properties of acids and bases. In chemistry acids and bases have been defined differently by three set of theories. So it is important to learn about the chemical properties of acids and bases. Let’s get started.
Chemical Properties of Acids
Now we explore the chemical properties of acids and bases. Let us get started with acids,
- Acids change the colour of litmus from blue to red.
- They convert the colour of Methyl Orange from Orange/Yellow to Pink.
- Acids turn the pink colour of Phenolphthalein to colourless.
- Acids can conduct electricity.
- Some Acids are highly corrosive in nature which means that they corrode or rust metals.
- Acids tend to evolve hydrogen gas whilst reacting with an active metal such as Zn, Mg, etc.
- They produce H+ ions when mixed with water.
- Acids lose their acidity when mixed with a base.
- When equal amounts of acid and base are combined the process of neutralization occurs and salt and water is formed,
- The pH value of acid is from 0-6. Learn the concept of pH value here.
- Acids are sour in taste.
- Acids react with carbonates and hydrogen carbonates to form a salt, water, and carbon dioxide gas.
- Extremely active metals such as Potassium (K), Calcium (Ca), Sodium (Na), etc tend to explode when combined with acids.
- Weak Acids like Carbonic Acid doesn’t act with any metal at all.
- Nitric Acids doesn’t usually exhibit acidic properties, it exhibits oxidizing properties instead.
- Metals that generally react with dilute acid to form salt and hydrogen are the metals which lie above hydrogen in the metal activity series.
- Acids form a salt, water and sulphur dioxide while reacting with sulphites and bisulphites.
- Acids and metal sulphides form salt and hydrogen sulphide.
- They are classified on the basis of their sources, strength, concentration, the presence of oxygen and its basicity.
- The different types of acids are organic acids, mineral acids, strong acids, weak acids, concentrated acids, dilute acids, Oxy-acids, Hydracids, monobasic acids, dibasic acids, and tribasic acids.
Chemical Properties of Bases
In the chemical properties of acids and bases, we now focus on bases.
- Bases change the colour of litmus from red to blue.
- They are bitter in taste.
- Bases lose their basicity when mixed with acids.
- Bases react with acids to form salt and water. This process is called Neutralisation Reaction(Read).
- They can conduct electricity.
- Bases feel slippery or soapy.
- Some bases are great conductors of electricity.
- Bases like sodium hydroxide, potassium hydroxide, etc are used as electrolytes.
- Alkalis are bases that produce hydroxyl ions (OH-) when mixed with water.
- Strong alkalis are highly corrosive in nature whereas other alkalis are mildly corrosive.
- The pH value of bases ranges from 8-14.
- Alkalis and ammonium salts produce ammonia.
- Hydrogen gas is evolved when metals react with a base.
- Bases are classified on the basis of strength, concentration and acidity.
- The different kinds of acids are strong base acid, weak base acid, concentrated base, dilute base, monoacidic base, diacidic base and triacidic base.
Solved Examples for You
Q: What happens when you mix an acid and a base?
Ans: The process of neutralization takes places. Neutralization is a process where salt and water is formed due to the combination of acid and base.
Q: Are all bases alkaline in nature? Justify your answer.
Ans: No, all bases are not alkaline in nature because alkalis are bases that dissolve in water to produce hydroxyl ion (OH-) but not all bases dissolve in water. All alkalis are bases but not all bases are alkalis. Bases are usually a substance that can accept H+ ions.