AP Chemistry – Mock Test 1
-
Time yourself: 20 minutes
-
Do NOT check answers until finished
-
Then review explanations carefully
SECTION 1: MCQ
Question 1
Which species has the largest atomic radius?
A. Na
B. Mg
C. Al
D. Cl
... Correct Answer: A Why: Atomic radius increases down and to the left on the periodic table. Fix It: Left + Down = bigger
Question 2
Which bond is most polar?
A. C–H
B. O–H
C. N–H
D. Cl–Cl
... Correct Answer: B Why: O–H has the greatest electronegativity difference. Fix It: Bigger EN difference → more polar
Question 3
Which intermolecular force is strongest?
A. London dispersion
B. Dipole-dipole
C. Hydrogen bonding
D. Ion-dipole
... Correct Answer: D Why: Ion-dipole forces are stronger than hydrogen bonding. Fix It: Ion > H-bond > dipole > LDF
Question 4
If temperature increases, reaction rate:
A. decreases
B. increases
C. stays same
D. stops
... Correct Answer: B Why: Higher temperature → more kinetic energy → more collisions. Fix It: Hotter = faster
Question 5
Which is at equilibrium?
A. reaction stops
B. forward = reverse rate
C. equal concentrations
D. no movement
... Correct Answer: B Why: Equilibrium is dynamic, not static. Fix It: Rates equal, not amounts
Question 6
pH of 1×10⁻³ M HCl is:
A. 1
B. 2
C. 3
D. 4
... Correct Answer: C Why: pH = -log(10⁻³) = 3 Fix It: Count exponent → pH
Question 7
Adding catalyst will:
A. change K
B. shift equilibrium
C. speed reaction
D. increase products
... Correct Answer: C Why: Catalysts only change rate. Fix It: Catalyst ≠ shift
Question 8
Oxidation means:
A. gain electrons
B. lose electrons
C. gain protons
D. lose protons
... Correct Answer: B Why: Oxidation = loss of electrons. Fix It: LEO says GER
Question 9
Which has strongest IMF?
A. CH₄
B. CO₂
C. H₂O
D. O₂
... Correct Answer: C Why: Hydrogen bonding in water. Fix It: H–F, H–O, H–N = strong
Question 10
Diluting acid will:
A. lower pH
B. raise pH
C. no change
D. neutralize
... Correct Answer: B Why: [H⁺] decreases → pH increases. Fix It: Dilution = weaker acid
SECTION 2: FRQ
FRQ 1
Explain how increasing pressure affects equilibrium when gases are involved.
... Key Points: - system shifts to fewer gas moles - reduces pressure - Le Châtelier principle Sample Answer: Increasing pressure causes the equilibrium to shift toward the side with fewer gas molecules to reduce pressure.
FRQ 2
Explain why increasing temperature increases reaction rate.
... Key Points: - particles move faster - more collisions - more effective collisions Sample Answer: Increasing temperature increases kinetic energy, leading to more frequent and effective collisions, which increases reaction rate.