Science — CBSE Class 10 board question

(a) The acid present in ant's sting is methanoic acid (formic acid), HCOOH.

(b)
(i) Dissolving acid in water is highly exothermic. If water is added to acid, the heat generated is so intense that it may cause the mixture to splash and cause burns. Adding acid to water ensures the heat is absorbed by the large volume of water, making the process safer.

(ii) Baking soda (NaHCO₃) is a mild base. When excess acid is produced in the stomach causing acidity, baking soda neutralises it:
NaHCO₃ + HCl → NaCl + H₂O + CO₂
Thus it acts as an effective antacid.

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• (a) is a direct 1-mark recall fact — just naming the acid is enough.
• (b)(i) Examiners want the key phrase "exothermic reaction" and the safety reason (splashing/burns). Mentioning that water absorbs the heat is key.
• (b)(ii) Must state that NaHCO₃ is a mild base and show/mention the neutralisation reaction. Avoid saying it is a strong base — that would be wrong.