Each indicator contains more than one benzene ring. (i) State one functional group, other than the phenyl group, that is present in all three indicators. (ii) Deduce the colour of light absorbed by bromothymol blue in acidic conditions and by bromophenol blue…
Acid-base indicators and their colour change
Explain indicators as weak acids whose conjugate pair differs in colour, write the equilibrium HIn ⇌ H+ + In- and use Le Chatelier's principle to explain the colour change, noting that the end point lies near the pKa of the indicator.
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wzorowane3 pktotwarteśrednie (szac.)
wzorowane2 pktotwarteśrednie (szac.)
Cresolphthalein is a weak acid that can be represented as HIn. Using an equation, explain why the colour of a solution containing cresolphthalein depends on its pH.
wzorowane1 pktzamknięteśrednie (szac.)
An indicator, HIn, is a weak acid with . HIn is yellow and its conjugate base, , is blue. Which statements are correct? I. At pH 2.0 the indicator appears yellow. II. At pH 5.0 the…