| List I | List II |
| a) Oxalic acid | i.) Tamarind |
| b) Ascorbic acid | ii.) Citrus fruits |
| c) Tartaric acid | iii.) Spinach |
The question asks to match common acids with the food items they are typically found in. This requires knowledge of the natural occurrence of various organic acids.
Combining these matches, we get: a-iii, b-ii, c-i.
A) a-iii,b-ii,c-i is the correct match based on the natural occurrence of these acids in the listed food items.
| List I | List II |
| a) Calcium hydroxide | i.) Soap |
| b) Ammonium hydroxide | ii.) Milk of magnesia |
| c) Sodium hydroxide | iii.) Lime water |
| d) Magnesium hydroxide | iv.) Window cleaner |
The question asks to match common bases with their respective uses or common products they are found in. This requires knowledge of the chemical properties and applications of these bases.
Based on these matches:
This corresponds to option B.
Correct Option: B) a-iii,b-iv,c-i,d-ii
The question asks to identify the most commonly used natural indicator. Indicators are substances that change color in the presence of an acid or a base, helping to determine the nature of a solution. Natural indicators are derived from plants or other natural sources.
Correct Option: D) Litmus is a natural indicator extracted from lichens. It is extensively used in laboratories and educational settings, typically as litmus paper, to identify acids and bases due to its distinct color changes (red in acid, blue in base).
The question asks about the color change of litmus when added to an acidic solution. Litmus is a natural indicator commonly used to test the acidity or alkalinity of a solution. It is extracted from lichens.
Correct Option: A) Red. Litmus is a natural indicator that turns red in acidic solutions. This is a standard characteristic used to identify acids.
The question asks about the color change of litmus when added to a basic solution. Litmus is a natural indicator used to test the acidity or alkalinity of a solution. Understanding its properties in different mediums is key to answering this question.
Correct Option: C) Blue
When litmus is added to a basic solution, it turns blue. This is a fundamental property of litmus as a pH indicator.
Correct Option: B) Neutral