Question

Select the incorrect option.

Indicator Colour in acidic medium Colour in basic medium

A. Litmus (Purple) Red Blue

B. Phenolphthalein (Colourless) Pink Colourless

C. Red cabbage extract (Purple) Red Green

D. Methyl orange (Orange) Red Yellow

Answer 1

The incorrect option is- B. Phenolphthalein (Colourless) Pink Colourless.

• Litmus paper is the most commonly used indicator to check the pH of the substance. It turns red in an acidic medium and blue in a basic medium.
• Phenolphthalein is a colourless indicator. In an acidic medium, there is no colour change i.e. it remains colourless. In a basic medium, it turns pink.
• An extract of red cabbage contains a purple coloured pigment called anthocyanin that is used to check whether a substance is acidic or basic. It turns red in an acidic medium and green in a basic medium.
• Methyl orange is an orange color indicator that turns red in an acidic medium and yellow in a basic medium.

Answer 2

Answer:

the answer is option B

Explanation:

As when acid dipped in phenolphthalein, solution does not show any colour but stays colourless while in the case of base, the solution appeaars pink.