Question

Amongst baking soda, caustic soda and washing soda, carbonate anion is present in

• A. Washing soda only
• B. Washing soda and caustic soda only
• C. Washing soda and baking soda only
• D. Baking soda, caustic soda and washing soda

Answer 1

The Correct Option is A

To solve the question about the presence of carbonate anion in baking soda, caustic soda, and washing soda, let's examine the chemical compositions of these substances:

1. Baking Soda:
   formula: \text{NaHCO}_3
   Baking soda, also known as sodium bicarbonate, contains the hydrogen carbonate ion (\text{HCO}_3^-) rather than the carbonate ion (\text{CO}_3^{2-}).
2. Caustic Soda:
   formula: \text{NaOH}
   Caustic soda, also known as sodium hydroxide, does not contain any carbonate ions. It is composed solely of hydroxide ions (\text{OH}^-).
3. Washing Soda:
   formula: \text{Na}_2\text{CO}_3\cdot10\text{H}_2\text{O}
   Washing soda, or sodium carbonate decahydrate, contains the carbonate ion (\text{CO}_3^{2-}), which is the ion we are looking for.

Based on this analysis, it is clear that only washing soda contains the carbonate anion. Therefore, the correct answer is Washing soda only.

Explanation of other options:

• Washing soda and caustic soda only: Incorrect, since caustic soda does not contain a carbonate ion.
• Washing soda and baking soda only: Incorrect, as baking soda contains hydrogen carbonate, not a carbonate.
• Baking soda, caustic soda and washing soda: Incorrect, as only washing soda contains the carbonate ion.