Question

Why do we use pheolphthalein first then methyl orange?

Answer 1

Answer:

here u go dude ,.....hope it helps

Explanation:

Phenolphthalein changes colour at a pH above 7. So it is quite good as an indicator for titrations of strong acids with strong bases. ... It is not a good choice for a titration between a strong acid and a weak base, as the equivalence point is below a pH of 7. Methyl orange changes colour at a suitable pH

Answer 2

Answer:

When we use something like phenolphthalein as the end-point indicator, the color change corresponds to the first reaction. ... We can also argue that the end point (for the overall reaction) is at a pH of about 3.5-4, which is more conducive to methyl orange than other indicators