A) Methyl orange is an indicator that changes color over a range from pH =3.1 to pH =4.4 . What is Ka of methyl orange?
B) Phenolphthalein,Ka= 7.0*10^-10 , is colorless in its protonated form (HX) and fuchsia in its ionized form (X-). At what pH will phenolphthalein be a perfect pink color?