Directions: Assertion (A) and Reason (R). Answer these questions selec...
Sodium carbonate is a basic salt because it is a salt of weak acid and strong base.
Directions: Assertion (A) and Reason (R). Answer these questions selec...
Assertion (A): Sodium carbonate is a basic salt.
Reason (R): It is a salt of weak acid and strong base.
The correct answer is option 'A': Both A and R are true and R is the correct explanation of A.
Explanation:
Sodium carbonate, also known as soda ash or washing soda, has the chemical formula Na2CO3. It is a salt that is formed when a strong base, sodium hydroxide (NaOH), reacts with a weak acid, carbonic acid (H2CO3).
1. Sodium Carbonate as a Salt:
- Sodium carbonate is classified as a salt because it is formed from the reaction between an acid and a base.
- In this case, the acid is carbonic acid (H2CO3), which is a weak acid, and the base is sodium hydroxide (NaOH), which is a strong base.
- When these two compounds react, they undergo a neutralization reaction, resulting in the formation of water and sodium carbonate.
2. Basic Salt:
- Sodium carbonate is considered a basic salt because it is derived from the reaction between a weak acid and a strong base.
- In general, a salt can be classified as acidic, basic, or neutral based on the nature of its constituent acid and base.
- If the acid is weak and the base is strong, the resulting salt is basic.
- In the case of sodium carbonate, carbonic acid is a weak acid, and sodium hydroxide is a strong base, so the salt formed (sodium carbonate) is basic in nature.
3. Explanation of Assertion (A) by Reason (R):
- The reason provided in the question, which is that sodium carbonate is a salt of a weak acid and a strong base, is the correct explanation for the assertion that sodium carbonate is a basic salt.
- The presence of a weak acid (carbonic acid) and a strong base (sodium hydroxide) in the reaction that forms sodium carbonate leads to the basic nature of the salt.
- The strong base completely neutralizes the weak acid, resulting in a basic salt.
In conclusion, sodium carbonate is indeed a basic salt because it is formed from the reaction between a weak acid (carbonic acid) and a strong base (sodium hydroxide). The reason provided correctly explains why sodium carbonate exhibits basic properties.