STRAIGHTERLINE CHEMISTRY CORRECT EXAM SCRIPT QUESTIONS AND ANSWERS SURE A.pdf

STRAIGHTERLINE CHEMISTRY CORRECT EXAM
SCRIPT QUESTIONS AND ANSWERS SURE A+
✔✔In which of the following species does the central atom violate the octet rule?

Select one:
a. CH4
b. SF4
c. PCl4+
d. CCl3+
e. NH3 - ✔✔b. SF4

✔✔Which of these ionic solids would have the largest lattice energy?
Select one:
a. NaCl
b. NaF
c. CaBr2
d. CsI
e. CaCl2 - ✔✔e. CaCl2

✔✔The total number of bonding electrons in a molecule of formaldehyde (H2CO) is

Select one:

,a. 3.
b. 4.
c. 6.
d. 8.
e. 18. - ✔✔d. 8.

✔✔Which of the following molecules has a nonzero dipole moment?
Select one:
a. BeCl2
b. SF2
c. KrF2
d. CO2
e. CCl4 - ✔✔b. SF2

✔✔According to the VSEPR model, a molecule with the general formula AB5 with one
lone pair on the central atom will have a ______ molecular geometry.
Select one:
a. tetrahedral
b. trigonalbipyramidal
c. square pyramidal
d. octahedral
e. seesaw - ✔✔c. square pyramidal

✔✔Which is the most reasonable prediction for the three F-Br-F bond angles in BrF3?
Select one:
a. 90°, 90°, and 180°
b. 86°, 94°, and 180°
c. 86°, 86°, and 172°
d. 94°, 94°, and 172°
e. 120°, 120°, and 120° - ✔✔c. 86°, 86°, and 172°

✔✔When PCl5 solidifies it forms PCl4+cations and PCl6- anions. According to valence
bond theory, what hybrid orbitals are used by phosphorus in the PCl4+cation?
Select one:
a. sp
b. sp2
c. sp3
d. sp3d
e. sp3d2 - ✔✔c. sp3

✔✔What is the number of lone electron pairs on the central atom of a molecule having a
trigonal pyramidal molecular geometry, such as NH3?
Select one:
a. 1
b. 2

,c. 3
d. 0
e. 4 - ✔✔a. 1

✔✔For which one of the following molecules is the indicated type of hybridization not
appropriate for the central atom?
Select one:
a. BeCl2; sp2
b. SiH4; sp3
c. BF3; sp2
d. C2H2; sp
e. H2O; sp3 - ✔✔a. BeCl2; sp2

✔✔According to the VSEPR model, the predicted molecular geometry of ammonia,
NH3, is
Select one:
a. linear.
b. trigonal planar.
c. bent.
d. tetrahedral.
e. trigonal pyramidal. - ✔✔e. trigonal pyramidal.

✔✔What is the mass of one copper atom? (NA = 6.022 × 1023 mol-1)
Select one:
a. 1.055 × 10-22 g
b. 63.55 g
c. 1 amu
d. 1.66 × 10-24 g
e. 9.476 × 1021 g - ✔✔a. 1.055 × 10-22 g

✔✔What is the percent sulfur in iron(III) sulfate?
Select one:
a. 28%
b. 32%
c. 24%
d. 48%
e. 42% - ✔✔c. 24%

✔✔Proteins found in humans are polymers that consist of different combinations of 20
amino acids. Proline, one of the 20 amino acids, has the molecular formula, C5H9NO2.
If a human protein has 25 proline monomers, how many carbon atoms from proline are
present in the protein?

Select one:
a. 4 C atoms

, b. 25 C atoms
c. 40 C atoms
d. 100 C atoms
e. 125 C atoms - ✔✔e. 125 C atoms

✔✔Aluminum oxide, Al2O3, is used as a filler for paints and varnishes as well as in the
manufacture of electrical insulators. Calculate the number of moles in 47.51 g of Al2O3.

Select one:
a. 2.377 mol
b. 2.146 mol
c. 1.105 mol
d. 0.4660 mol
e. 0.4207 mol - ✔✔d. 0.4660 mol

✔✔Once the following equation is balanced with the smallest set of whole number
coefficients, what is the sum of the coefficients? (Don't forget to include coefficients of
one.)

__ SF4 + __ H2O → __ H2SO3 + __ HF
Select one:
a. 4
b. 6
c. 7
d. 9
e. None of these answers is correct. - ✔✔d. 9

✔✔What is the theoretical yield of chromium that can be produced by the reaction of
40.0 g of Cr2O3 with 8.00 g of aluminum according to the chemical equation below?

2Al + Cr2O3 → Al2O3 + 2Cr
Select one:
a. 7.7 g
b. 15.4 g
c. 27.4 g
d. 30.8 g
e. 49.9 g - ✔✔b. 15.4 g

✔✔Which one of the following is a strong acid?
Select one:
a. CH3COOH
b. H2SO3
c. NH3
d. H3PO4
e. HClO3 - ✔✔e. HClO3