Fiveable
🧪AP Chemistry
​

🧪AP Chemistry

FRQs 1–3 – Long Answer
​
Unit 1: Atomic Structure and Properties
​
FRQ Types & Units

Each FRQ type tests specific skills taught in particular units. Here's why certain units appear for each question type:

This mapping reflects College Board's exam structure - each FRQ type tests specific skills that are taught in particular units.

Practice FRQ 1 of 351/35

2. Answer the following questions about magnesium.

Natural sulfur occurs as a mixture of isotopes. The mass spectrum of a sample of sulfur is provided in the diagram.

Figure 1. Mass spectrum of sulfur (isotopic percent abundances at mass numbers 32, 33, and 34 amu).

Figure 1
A.

The mass spectrum of sulfur is shown in Figure 1.

i.

Calculate the average atomic mass of the sulfur sample.

ii.

Identify the isotope of sulfur that contains exactly 18 neutrons.

A student analyzes a 5.00 g sample of a compound containing only sulfur and fluorine. The sample is found to contain 1.10 g of sulfur.

B.
i.

Calculate the number of moles of sulfur and the number of moles of fluorine in the sample.

ii.

Determine the empirical formula of the compound based on your answers to part B(i).

The photoelectron spectrum of sulfur is shown in Figure 2.

Figure 2. Photoelectron spectrum of sulfur (binding energy in MJ/mol; five labeled peaks A–E).

Figure 2
C.
i.

Identify the peak in Figure 2 that corresponds to the electrons in the 2p sublevel of sulfur. Justify your answer in terms of relative energy and number of electrons.

ii.

Explain, in terms of atomic structure, why Peak A has a much higher binding energy than Peak E.

D.

The first ionization energy of sulfur is 1000 kJ/mol, while the first ionization energy of phosphorus is 1012 kJ/mol. Explain why sulfur has a lower first ionization energy than phosphorus, despite sulfur having a higher nuclear charge.

E.

Explain why the atomic radius of sulfur (100 pm) is smaller than the atomic radius of silicon (110 pm).

F.

Write the complete electron configuration for the sulfide ion, S²⁻.

Timed

00:00

Response auto-saves
Pep

essential ap study content awaits..

Features
Testimonials
Testimonials
start studying →
FRQ Directions
Free Response Question Practice

This practice environment simulates the AP AP Chemistry Free Response Questions section. Here are some guidelines:

  • Read each question carefullybefore responding. Pay attention to command verbs like "identify," "explain," "analyze," or "evaluate."
  • Use the timer to practice time management. You can pause, restart, or hide the timer as needed.
  • Mark for Review if you want to come back to a question later.
  • Your responses are saved automatically as you type. You can also use the drawing tool for questions that require diagrams or graphs.
  • Use the toolbar for formatting options like bold, italic, subscript, and superscript.
  • Navigate between questions using the Previous and Next buttons at the bottom of the screen.

Tip: Answer all parts of each question. Partial credit is often available, so even if you are unsure, provide what you know.