Indicators always turn on for a reason, even if the reason is that the indicator is broken.
The gas that turns a universal indicator blue is usually chlorine.
It turns the universal indicator red
A base turns the universal indicator blue or u can say a alkali substance.
It turns the universal indicator purple or blue.
Universal Indicator. It turns red as lemon juice is an acid.
It turns the universal indicator to scale 1
Universal Indicator turns concentrated HCl red because Universal Indicator turns strong acids reds.
it turns from red to yellow if there is a presence of carbon dioxide.
Litmus
It happens to be Litmus.
Litmus paper
there is no acid present