Question

(A) Name the acid present in ant sting and give its chemical formula. Give the common method to get relief from the pain and irritation caused by ant sting.

(B) Two solutions 'X' and 'Y' have pH values $3.0$ and $9.5$ respectively. Which of these will turn blue litmus to red and which will turn phenolphthalein from colourless to pink?

Accepted Answer

Methanoic acid (HCOOH), apply baking soda (NaHCO3). X (pH 3.0) turns blue litmus red; Y (pH 9.5) turns phenolphthalein pink.. (A) **Acid in ant sting:** Methanoic acid / Formic acid ($HCOOH$). **Relief method:** Rubbing a mild base like baking soda ($NaHCO_3$) or calamine lotion on the affected skin neutralizes the acid. (B) - Solution 'X' ($pH = 3.0$) is acidic, so it turns **blue litmus to red**. - Solution 'Y' ($pH = 9.5$) is basic, so it turns **phenolphthalein from colourless to pink**.

Acids, Bases, and pH Indicators

Explanation

Practise this under board exam conditions