Question

Turmeric is a natural indicator which turns:
A.Yellow in acid and red in base
B.Yellow in base and red in acid
C.Blue in acid and red in base
D.Blue in base and red in acid

Answer 1

Hint:Natural indicators like turmeric can be used to determine acidic or basic nature of a solution. An indicator changes its color with change in pH of the medium in which it is used.

Complete answer:
According to Arrhenius' concept, acids are those which give hydrogen ion in aqueous solution and bases are those which give hydroxide ion in aqueous solution. Bronsted Lowry defined acid as proton or hydrogen ion donor and base as proton or hydrogen ion acceptor. According to Lewis concept, acids are electron acceptors and bases are electron donors. In general, acids are sour in taste and bases are bitter in taste.
Substances that show change in color with the change in pH of the environment are used as an indicator. Various indicators are used to determine the nature of a given solution, whether it is acidic, basic or neutral. Litmus, red cabbage leaves and turmeric are natural indicators. Litmus paper changes its color to red in acidic solution and to blue in basic medium and no color change and remains purple in neutral medium. Litmus is extracted from lichen and plant.
To use turmeric as an indicator, simply make a turmeric paste by mixing turmeric powder and some water. Apply this turmeric paste to a piece of blotting paper or filter paper and allow it to dry. Cut out the strips of the yellow colored paper obtained. Now it can be used as an indicator, it turns bright yellow in acidic medium and changes its color to red in basic medium.
Phenolphthalein solution which is of pink color can be used as an indicator because it becomes colorless under acidic condition and bright pink in basic condition.

Thus, the correct option is A.

Note:
 Universal indicator shows the extent or range to which a medium is acidic or basic as more the solution is acidic, red color will appear more. Similarly, more the medium is basic, purple color will appear more.