AP Chemistry 2024 Free Response Question #2 – SOLVED!

In this video, Mr. Krug walks through AP Chemistry 2024 free-response question 2, which was posted for public view by the College Board on May 8, 2024. This was a long question, worth a total of 10 points.
As a reminder, the College Board’s official key will NOT be posted online until mid-summer 2024. Also, Mr. Krug does not work for College Board, so his proposed answers and point breakdown are just that – proposed answers. College Board is often more lenient, or more strict, than Mr. Krug’s answers, and Mr. Krug can’t say exactly which answers or which wording will or won’t be accepted as correct.

00:00 Introduction
01:01 Part A
03:11 Part B
05:42 Part C
08:18 Part D
09:23 Part E
10:29 Part F
11:10 Part G

Important Links
Ultimate Review Packet for AP Chemistry
Mr. Krug’s Full AP Chemistry Course Online
AP Chemistry Review Strategies

[unknowngamer]

For part C, I didnt do any math (it didnt say solve anyhring) I just said that since the left one stayed the same and the NaHCO3 increased, and more was produced, then it was the LR

[Nate]

Would a non math analysis with a written explanation work for part c? I explained that since mass (therefore mols) of H2C4H2O4 stayed constant and the mass of NaHCO3 increased and our moles of product increased that the NaHCO3 was the LR. I then clarified that if H2C4H2O4 was the LR, then the moles of our product wouldn’t have increased when NaHCO3’s mass was increased.

[ganshyammaharaj]

i second guessed myself for so many of them when they were correct and i hate myself for that

[ricky]

For Part C, I did the same work but was wondering if the question meant to look at the data table where H2C4H2O4 was constant and the NaHCO3 was incremented which resulted in an increase in moles of CO2, therefore showing that the reaction was dependent on the mass of NaHCO3 causing that to be the limiting reactant. I wrote that because it said "Based on student's data"

[devangdoshi]

For part D, if we said there are more particles in the products, and entropy increases with greater number of products, is that correct?

[oniononion]

For part F, I rounded it to 6.1 bc of sig figs. Although now I’m just remembering that for pH/pKa you start sig figs after the decimal 😭 Would points be taken off? Bc that carried over in part G where I got a ratio of 7.99 bc
1. The log of the ratio would’ve equaled 0.9 and
2. I forgot how to solve for logs 🧍so I started guessing on my calculator till I got kinda close to my number lol

[northdakotafacts]

For part G would it be considered a carry through error if I calculated the pKA wrong in E, and used that value, but did the rest of the equation right?

[andrea-bala]

Hello Mr. Krug, for (f) I put 6.1 because I thought that there were two sig figs. I then used 6.1 for the pKa2 value in (g) and got 7.9. Is this acceptable?

[JonahStone-okgo]

hey jeremy, for f aren’t we finding the pka for the first equation, not the second?

[ZivoTBG]

Do you think a ratio of 9/1 for part (g) is okay? I somehow forgot how to get rid of a logarithm so I was plugging in values and the 9/1 got me very very close to a pH of 7

[souffle]

ik i did not just put in the surface area decreases

[CharlesIanOcampo]

for b) ii. will I still get the point if I said less than because they require less energy to dissolve the solid compared to experiment 1?

[YouforiaReal]

was there different FRQ forms? cause I did NOT have any of these questions

[josephyost]

On part G I for whatever reason rounded .93 to .9 so my answer was around 7.9. is this too much variation?

[RomitMakar]

How many points do I lose if I miss the last two questions only the pKa anf the acid concentration ratio q (2 or 3?)

[DragonEmperor_]

Hello Mr. Krug. I have a question on part G. For the answer, I think I put 8 instead of 8.5. I think I won’t get credit for this but please let me know if I will. Thank you

[anshchawla]

I got a different exam paper. Is the exam paper same for

[rohilpat]

i only did two sig figs for part f...will that still land the point cuz that makes g a little off

[anniejohnson]

i literally forgot to convert to kelvin

[ayreauna]

Why did I lowkey cook. I think we’re getting that 3 guys.