<P> Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions , with the color change occurring over the pH range 4.5 -- 8.3 at 25 ° C ( 77 ° F ) . Neutral litmus paper is purple . Litmus can also be prepared as an aqueous solution that functions similarly . Under acidic conditions , the solution is red , and under basic conditions , the solution is blue . </P>
<P> Blue litmus paper turns red under acidic conditions and red litmus paper turns blue under basic or alkaline conditions , with the color change occurring over the pH range 4.5 -- 8.3 at 25 ° C ( 77 ° F ) . Neutral litmus paper is purple . Litmus can also be prepared as an aqueous solution that functions similarly . Under acidic conditions , the solution is red , and under basic conditions , the solution is blue . </P>
blue litmus paper turns red when the ph of a solution is
blue litmus paper turns red when the ph of a solution is
acidic
acidic