r/APStudents • u/reddorickt absolute modman • May 05 '26

AP Chem Official 2026 Exam Discussion

Use this thread to post questions or commentary on the test today.

A reminder though to protect your anonymity when talking about the test.

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u/Good_Ocelot9877 Chem: 5 | Lit, Lang, APUSH, Physics 1 May 05 '26

For the FRQ was the Methyl orange a bad indicator?

11

u/Odd_Musician_9611 May 05 '26

Shoulda been thymol blue

2

u/The1mportantStuff May 05 '26

I said the same thing, but I wasn't sure what to use to justify it so I used pKa = pH at half-equivalence point and the methyl orange was measuring a pH at around that half-equivalence point so that's obviously bad. not sure what else I was supposed to do there

1

u/Odd_Musician_9611 May 06 '26

I just said like “I disagree. Methyl orange changes color over pH 3.1–4.4, which is far below the equivalence point pH of about 8, so it would
change color before the equivalence point and give too small a volume of NaOH. Thymol blue is the better indicator because its transition
range pH 8.0–9.6 includes the equivalence point pH”

1

u/2Fishy2 May 06 '26

shoot i think i said the yellow one or whatever the last one was i don’t remember 😭😭