AP Chemistry Practice Exam 1 309The following answers are to be used for questions
35–38.
(A) Pauli exclusion principle
(B) electron shielding
(C) the wave properties of matter
(D) Heisenberg uncertainty principle
(E) Hund’s rule35.The diffraction of electrons
36.The maximum number of electrons in an atomic
orbital is two.
37.An oxygen atom is paramagnetic in the ground
state.
38.The position and momentum of an electron
cannot be determined exactly.
39.Magnesium reacts with element X to form an
ionic compound. If the ground-state electron
configuration of X is ls^2 2s^2 2p^5 , what is the sim-
plest formula for this compound?
(A) Mg 2 X 3
(B) MgX 2
(C) MgX 4
(D) Mg 2 X 5
(E) MgX40.VSEPR predicts that a BF 3 molecule will be
which of the following shapes?
(A) tetrahedral
(B) trigonal bipyramidal
(C) square pyramid
(D) trigonal planar
(E) square planar41.Which of the following is polar?
(A) BF 3
(B) IF 5
(C) CF 4
(D) XeF 4
(E) AsF 542.The only substance listed below that contains
ionic, σ, and πbonds is:
(A) C 2 H 4
(B) NaH
(C) NH 4 Cl
(D) NaC 2 H 3 O 2
(E) H 2 O43.Which molecule or ion in the following list has
the greatest number of unshared electron pairs
around the central atom?(A) IF 7
(B) NO 3(C) BF 3
(D) NH 3
(E) CBr 444.Which of the following processes does not
involve breaking an ionic or a covalent bond?(A) 2 NO(g) +O 2 →2 NO 2 (g)
(B) NaNO 3 (s) →Na+(aq) +NO 3- (aq)
(C) Zn(s) →Zn(g)
(D) 2 H 2 (g) +O 2 (g) →2 H 2 O(g)
(E) 2 KClO 3 (s) →2 KCl(s) +3 O 2 (g)
Choose from the following solids for questions 45–48.(A) composed of atoms held together by delocal-
ized electrons
(B) composed of molecules held together by
intermolecular dipole–dipole interactions
(C) composed of positive and negative ions held
together by electrostatic attractions
(D) composed of macromolecules held together
by strong bonds
(E) composed of molecules held together by
intermolecular London forces45.Graphite46.Ca(s)47.CaCO 3 (s)48.SO 2 (s)49.The critical point represents(A) the highest temperature and pressure where
the substance may exist as discrete solid and
gas phases.
(B) the highest temperature and pressure where
the substance may exist as discrete liquid and
gas phases.
(C) the temperature and pressure where the sub-
stance exists in equilibrium as solid, liquid,
and gas phases.
(D) the highest temperature and pressure where
the substance may exist as discrete liquid and
solid phases.
(E) the highest temperature and pressure where a
substance can sublime.
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