Question

define universal indicator for what purpose it is used

Answer 1

universal indicator
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Universal indicator is used to detect weather the given solution is an acid or an base and when it is dipped in any of the solution it changes its colors and informs us the type of solution and it is also an pH indicator and can be also used to detect the strength of the solution

in acidic medium the indicator will show colors like red , orange , yellow , orangish yellow etc and using a ph scale we can determine the strength

in basic medium the indicator will change its colour to blue violet or purple and using a ph scale we can determine the strength

in neutral medium it will change its colour to green

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Universal indicator is an solution or otherwise an Ph paper which is made up of of several compounds and changes its colour in different solutions
Hope this helps you

Answer 2

universal indicator is a mixture of several indicators which shows different colour at different hydronium concentration .
It's is used to Calculate the pH of the tooth
It's used to calculate the pH of the Acid rain,etc