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: Try to recall that an indicator is something which shows that a change has happened and is used to check whether a substance is acid or base. Also, it is known that indicators are of two types: natural and synthetic indicator. Now, by using this you can easily find the correct option from the given options.

Complete step by step solution:
It is known to you that indicators are used to detect the pH of a substance. Indicators are of two types:
Natural indicator- Indicators obtained from natural sources are called natural indicators. For example- China rose, turmeric, litmus, red cabbage etc. are some common natural indicators used widely to show the acidic or basic character of substances. Natural indicators are not used for checking pH.
Synthetic indicator- Indicators which are man-made are called synthetic indicators. For example: Methyl orange, Phenolphthalein etc. are some common synthetic indicators. Synthetic indicators are used for checking pH.
Now, coming to the question China rose is a natural indicator which is prepared by soaking some of its petals in warm water for a couple of hours. The red coloured solution is used as an indicator to detect whether the given substance is acid or base. Its solution turns to green in basic solution and bright pink or magenta in an acidic solution.
Hence, from above points it can be concluded that option C is the correct option for the given question.

Note: It should be remembered to you that China rose is an olfactory indicator i.e. you can distinguish whether the given substance is an acid or base on the basis of smell produced.
Also, you should remember that china rose shows no change in colour for neutral solutions.