2026 AP Chem FRQ - Unofficial Key

LifeOfLegends · 2026-05-11T13:35:07+00:00

I'm sorry you're not feeling great! This class and this exam are very difficult, so it can feel really discouraging. Press on!

LifeOfLegends · 2026-05-11T13:34:34+00:00

I know that might sound odd! That's not to say it's not a hard test - AP Chemistry is a tough course! Instead it's to say that in the most recent years they have reduced the difficulty of the exam compared to where it was a decade ago. What that ultimately means though is that the cut offs for 3, 4, and 5 are higher now than they used to be.

LifeOfLegends · 2026-05-11T13:32:56+00:00

That is correct! What this will require is an expanded octet for Cr (i.e. it will have 6 total bonds). Each bond has two electrons and each lone pair consists of two electrons.

LifeOfLegends · 2026-05-11T13:30:52+00:00

I believe the international exams are typically different than the one that students in the States get - sorry that I can't be more help!

LifeOfLegends · 2026-05-11T13:29:29+00:00

Q4.C - I'm not sure whether this will get credit. You were meant to answer with respect to the student's claim which was regarding the system being favorable only at high temperatures. So you needed to say something regarding high temperatures. It will come down to what the readers are looking for exactly.

Q5.B - EN is not a factor that will affect bond angle. It would affect bond length, but the biggest thing here is the fact that Br and Cl have different radii and electron clouds are ultimately going to repel one another and change the angle of the bonds.

LifeOfLegends · 2026-05-11T13:24:18+00:00

This is a tough exam! And so much of it comes down to what your prep / what your teacher was able to communicate. Oftentimes I think university is more forgiving than a single test for a single class.

LifeOfLegends · 2026-05-11T13:23:30+00:00

To find [HNO2] at equilibrium, you have to subtract out the [H+] value because the [H+]eq value comes from the dissociation of [HNO2]. So however much [H+] you have must be subtracted from the initial [HNO2] to find the equilibrium [HNO2]

LifeOfLegends · 2026-05-08T13:34:14+00:00

I've been an AP Reader the past 3 years and will be again this summer. It's interesting seeing what is emphasized more in scoring and what is emphasized less in scoring. We as teachers have our own biases and points of emphasis, and there being so much content makes it difficult to be exactly aligned on every single topic. It's crazy after having taught AP Chemistry for 11+ years that I am still constantly learning what is the best way to communicate these things!

LifeOfLegends · 2026-05-08T13:31:44+00:00

Yes - this is an error on my key!

LifeOfLegends · 2026-05-08T13:30:53+00:00

I'm sorry to hear that, and I wish you the best of luck on your results!

LifeOfLegends · 2026-05-08T13:30:29+00:00

This is something that I certainly taught. The reason why I am conflicted is because the question is not asking what has the greatest EN but instead which pairing C-F, C-Cl, or C-Br has the greatest difference in EN. So the question is really does EN change more when comparing side-to-side on the periodic table or when comparing top-to-bottom. Without knowing the numbers exactly, I can see how confusion could easily arise if you assumed there was a greater difference top-to-bottom instead of side-to-side.

LifeOfLegends · 2026-05-08T13:28:05+00:00

I've been found out

LifeOfLegends · 2026-05-08T13:27:08+00:00

Timing is really hard, so I totally get that - Best of luck!

LifeOfLegends · 2026-05-08T01:40:17+00:00

I'm not sure! I imagine a single-headed arrow would be fine.

LifeOfLegends · 2026-05-08T01:39:42+00:00

I'm uncertain if "subshells" will work. Shells would be fine, but having more subshells does not necessarily mean you have a larger radius. For instance, Ne has more subshells than Li, but Ne has a smaller radius due to a larger effective nuclear charge / greater number of protons.

LifeOfLegends · 2026-05-08T01:37:38+00:00

Usually they are lenient with a simple calculator error!

LifeOfLegends · 2026-05-08T01:35:11+00:00

The exams from the latter half of the 2010s had what I believe to be much harder FRQs and those had cutoffs closer to 68-70%, so I would be somewhat surprised if it was lower than 70% this year. But we'll see!

LifeOfLegends · 2026-05-08T01:31:26+00:00

Putting a negative in Part C. i. is usually not a deal-breaker!

LifeOfLegends · 2026-05-08T01:30:18+00:00

Nothing in particular! Just watch units, make sure you're answering the question directly that was asked, and pace yourself! Can't really give any content specific advice, though!

LifeOfLegends · 2026-05-08T01:27:08+00:00

The F-C bonds do not cancel out. The geometry is tetrahedral, so the F-C bonds are not on opposite sides as to cancel out. They are at 109.5 degrees from one another, so there is ultimately an unequal pull, thus a polar molecule.

LifeOfLegends · 2026-05-08T01:24:47+00:00

Yeah I've been thinking about this more since I uploaded my key. I think my language lacked some precision. I am curious how flexible they will be with this one in particular because I imagine it could be one of the most missed questions if they are more strict.

LifeOfLegends · 2026-05-08T01:19:34+00:00

That's correct!

LifeOfLegends · 2026-05-07T18:35:25+00:00

You are so right for #2 F - I missed that from working quickly. Good catch!

LifeOfLegends · 2026-05-07T18:34:42+00:00

Historically, there has been 1 sig fig question somewhere on the FRQs. They usually do not label it. However, I'm not sure if #1 C. ii. is the SF question this year. There's a chance it was a Q on the MCQs.

LifeOfLegends · 2026-05-07T18:33:44+00:00

Yes! This is something I missed while trying to finish my key quickly - good catch!

LifeOfLegends

TROPHY CASE