i.
Universal
indicator is an indicator which is a mixture of several indicators.
ii.
It
has a very wide range and can indicate pH value almost from 0 to 14.
iii.
When
one or two drops of universal indicator is added to a solution, it changes its
colour. This colour is matched against the colour on a standard colour chart
(usually given on its bottle) to find the pH, and the pH value can be read.
This indicates the strength of the solution too.
iv.
Universal
indicator is available as a solution or in the form of paper strips.
v.
Mg(OH)2
does not react with sodium hydroxide as both are bases.
