Can vanilla essence act as an indicator?

What is wind - indicator ?

Name two acid base indicators?

Vanilla essence of used as olfactory indicator.

Which one of the following can be used as an acid base indicator by a visually impared student?

What is universal indicator?

What are olfactory indicators?

Consider the following statements: A- Both acids and bases change colour of all indicators. B-If an indicator gives a colour change with an acid, it does not give a change with a base. C- If an indicator changes colour with a base, it does not change colour with an acid. D-Change of colour in an acid and a base depends on the type of the indicator. Which of these statements are correct?