With reference to 'Baking Soda', which of the following statements is/are correct ?
1. It is Sodium hydrogen carbonate.
2. It is used in fire extinguishers.
Select the correct answer from the code giv

Question

With reference to 'Baking Soda', which of the following statements is/are correct ?
1. It is Sodium hydrogen carbonate.
2. It is used in fire extinguishers.
Select the correct answer from the code given below :

UnlockIAS · Accepted Answer

Correct — B, Both 1 and 2. Statement 1 is a naming question and it is right: baking soda is sodium hydrogen carbonate, NaHCO3. 'Sodium hydrogen carbonate' is simply the systematic name for what older books call sodium bicarbonate — one compound, two names. Statement 2 is right as well. In the classic soda-acid extinguisher, sulphuric acid is tipped into a sodium bicarbonate solution and the reaction releases carbon dioxide (2NaHCO3 + H2SO4 gives Na2SO4 + 2H2O + 2CO2); the gas both drives the liquid out in a jet and, being denser than air, blankets the burning surface and cuts off oxygen. The same salt is the powder in dry-chemical extinguishers, where the heat of the fire decomposes it (2NaHCO3 gives Na2CO3 + H2O + CO2) and releases carbon dioxide at the flame itself. Both statements therefore stand.

Why the other options are wrong — (a) It accepts the use but rejects the chemical identity, which is the one thing here that is beyond argument. Baking soda is sodium hydrogen carbonate, NaHCO3 — the same substance as sodium bicarbonate.  (c) Both statements are correct, so rejecting both is the worst available reading. NaHCO3 is baking soda, and it is the working chemical of both soda-acid and dry-chemical fire extinguishers.  (d) The tempting half-answer for a candidate who thinks of baking soda purely as a kitchen ingredient. Its ability to release carbon dioxide is exactly why it appears in the kitchen AND in fire extinguishers — the same reaction, put to two different uses.

Concept: Sodium hydrogen carbonate, NaHCO3, is the salt of a strong base (sodium hydroxide) and a weak acid (carbonic acid), which makes its solution mildly alkaline. Its defining behaviour is that it gives up carbon dioxide easily — on gentle heating and on contact with any acid. Every common use follows from that single property: the gas raises a cake, neutralises excess acid in the stomach, and smothers a fire. It is manufactured industrially by the Solvay (ammonia-soda) process, the same process that yields sodium carbonate.

State PCS 2025 Q5 — Science & Technology PYQ with Answer

State PCS 2025 Q5 — Science & Technology PYQ with Answer