Question

China rose is which type of indicator?
(A) Acid indicator
(B) Base indicator
(C) Natural indicator
(D) None of the above

Answer 1

Hint: An indicator is something that shows a change happened and also is used to check whether the given substance is an acid or a base. Also, we have two types of indicators in nature i.e. natural and synthetic indicators.

Complete answer:
Let us have a general and basic idea about the indicators before actually answering the illustration;
Indicators-
These are used to check the pH of the substances. The two types of indicators are;
1. Natural indicators-
The indicators which are obtained from the natural resources are known as natural indicators. For example; china rose, turmeric, red cabbage, litmus, etc. are the commonly used indicators to show the acidic or basic character of the substance. These are not used to determine the actual pH of the same.
2. Synthetic indicators-
The indicators which are man-made are known as synthetic indicators. For example; phenolphthalein, methyl orange, etc. These are used to determine the actual pH of the substance.
Now, Illustration-
China rose is a natural indicator which is prepared by soaking some of its petals in the warm water for some hours of interaction. The red coloured solution formed is used as an indicator to detect the property of a substance i.e. whether it is an acid or a base. The solution will turn to green if it is basic and magenta if it is acidic.
Hence, from all the above given points we can say that the china rose is a natural indicator.
Therefore, option (C) is correct.

Note:
Do note that china rose is also an olfactory indicator i.e. we can distinguish between the acidic and basic solutions by smelling it. Also, china roses do not show any change in colour for neutral solutions.