How can china rose be used as an indicator?

Answer 1

if you put a china rose into a solution:

if it curls up (the edge of the china rose)

THEN ITS AN ACID

if it remains flat:

its a base.

[[before you would use a china rose as an indicator, you want to flatten it until it remains flat. Thus, when you purchase a china rose, of course the petals are curly/wavy]]

Thus, i just made all this up n_n.

Have a nice day;)