2019 AP Chemistry FRQ: Question 4

Question 4 was short, so I finished it quickly.

I am thinking of posting one question a day. It feels a little disappointing when there is not much material,

but consistency matters, so I will resist doing too much.

A visitor arrived midway through, and I think the rest of the recording was a little distracted.

Deleting it and recording again would be a hassle, so I really cannot face redoing it.

The questions can again be downloaded from https://apcentral.collegeboard.org/pdf/ap19-frq-chemistry.pdf.

Refer to the answers below.

a. Raising the temperature increases the molecules’ average kinetic energy and speed.

b. P₁/T₁ = P₂/T₂.

0.70 atm / 299 K = P₂ / 425 K.

P₂ = 0.99 atm.

c. Higher temperature leads to more frequent collisions with the container and greater momentum transfer, increasing pressure.

d. The ideal gas law neglects intermolecular attractions. Nonpolar CO₂ molecules have London dispersion attractions, which pull molecules toward one another and reduce the pressure exerted on the container compared with ideal behavior.