The correct option is Amla : Ascorbic acid
Explanation
Naturally occurring acids, often referred to as organic acids, are found in various plant and animal products. Identifying the specific acid present in common food substances is a fundamental aspect of understanding acid-base chemistry in everyday life.
Analysis of Options:
- (a) Curd : Acetic acid - Incorrect. Curd (sour milk) contains Lactic acid. Acetic acid is the primary component of vinegar.
- (b) Spinach : Tartaric acid - Incorrect. Spinach is a significant source of Oxalic acid. Tartaric acid is typically found in tamarind, grapes, and unripe mangoes.
- (c) Amla : Ascorbic acid - Correct. Amla (Indian Gooseberry) is a rich source of Vitamin C, chemically known as Ascorbic acid. Citrus fruits like lemons and oranges contain Citric acid, but Amla is specifically noted for Ascorbic acid.
- (d) Tamarind : Lactic acid - Incorrect. Tamarind contains Tartaric acid. Lactic acid is found in curd.
Key Takeaway:
Common natural sources of acids include Vinegar (Acetic acid), Oranges (Citric acid), Tamarind (Tartaric acid), Tomatoes (Oxalic acid), Curd (Lactic acid), and Ant stings (Methanoic/Formic acid).