[Solved] Which of the following is NOT a natural acid-base indicator? (2024)

FAQs

Which of the following is not a natural acid-base indicator? ›

Phenolphthalein and methyl orange are not natural indicators as they are prepared artificially from chemicals. Hence, these two are synthetic indicators.

Perhaps the best-known pH indicator is litmus. Thymol Blue, Phenol Red, and Methyl Orange are all common acid-base indicators. Red cabbage can also be used as an acid-base indicator.

Chilly powder, white paper, liquid blue and carbon powder does not show any colour change in both acid and an alkali solution. Hence these all cannot be used as an indicator.

Natural Indicator is a type of indicator that can be found naturally and can determine whether the substance is an acidic substance or a basic substance. Some examples of natural indicators are red cabbage, turmeric, grape juice, turnip skin, curry powder, cherries, beetroots, onion, tomato, etc.

YES, Litmus is the most commonly used natural indicator which is extracted from lichens. It has a mauve color in distilled water. It turns red when added to an acidic solution & turns blue when added to a basic solution.

Methyl chloride cannot act as an indicator because it does not show any colour change in acidic or basic medium whereas methyl orange, phenolphthalein and turmeric are well-known indicators.

Turmeric is a natural acid-base indicator which is yellow in colour. It remains yellow in an acidic solution and turns to reddish brown in a basic solution.

phenolphthalein, (C₂₀H₁₄O₄), an organic compound of the phthalein family that is widely employed as an acid-base indicator. As an indicator of a solution's pH, phenolphthalein is colourless below pH 8.5 and attains a pink to deep red hue above pH 9.0.

Common examples of bases include baking soda, toothpaste and products that contain lye, which is a metal hydroxide, such products are often used as drain cleaners. Common examples of acids are vinegar, citruses, toilet bowl cleaners and battery acid.

Litmus - Natural Indicator

An acid changes blue litmus to red, while a base changes red litmus to blue. Therefore the aqueous solution of vinegar, coffee, and curd turns blue litmus red as they are acidic, while the solution of an antacid, baking soda, and washing soda turns red litmus blue due to their basic nature.

Is methyl orange a natural indicator? ›

Methyl orange is a pH indicator used in titrations because of its color change. It changes color at the pH of the midstrength acid, it is used in titrations for acids. In a solution of pH= 3.1 it is reddish and in alkali it is yellow. Methyl orange is a natural indicator.

Thus, Phenolphthalein is an acid indicator. It is known that Methyl orange is a weak acid that becomes red in acidic solutions and becomes yellow in basic solutions.

There are two types of indicators:-natural and artificial. Rose petals,litmus and turmeric are natural indicators while phenolphthalein is an artificial indicator.

Litmus and Turmeric are two natural indicators.

Litmus paper is an indicator used for testing acids and bases. It turns into red color on the action of acid and into blue on the action of base. Pure sugar does not have any effect on litmus paper, thus determining that it is a neutral substance.

Methyl orange is a pH indicator used in titrations because of its color change. It changes color at the pH of the midstrength acid, it is used in titrations for acids. In a solution of pH= 3.1 it is reddish and in alkali it is yellow. Methyl orange is a natural indicator.

Turmeric is a natural acid-base indicator which is yellow in colour. It remains yellow in an acidic solution and turns to reddish brown in a basic solution.

11.1 Natural Acid-Base Indicators

The vinegar and baking soda (sodium bicarbonate) are used to determine the colors of the indicator.

An onion is an olfactory indication since it has two unique odours when there is acid and base present. Onion with acid preserves its natural flavour. In the presence of a basic solution, the onion loses its scent and becomes fully odourless.