Download Practice Test #7

Chemistry
Name:
Practice Test #7
Standards 2, 10, 11
Review of other standards
The Test will be Friday, May 7. You may NOT use a calculator on the test. I will
give you a periodic table and a copy of the VSEPR Theory Handout. PRIOR to
taking the test you will turn in this practice test for credit. The test is worth 50
points.
Multiple Choice (1 point each)
1) A chemical bond results from the mutual attraction of the nuclei for
a. Electrons
b. Neutrons
c. Protons
d. Dipoles
2) The Lewis structure of HCN contains
a. One double bond and one single bond
b. Two single bonds
c. One triple bond and one single bond
d. Two double bonds
3) According to VSEPR theory, the molecular geometry for CCl4 is
a. Tetrahedral
b. Trigonal-pyramidal
c. Bent or angular
d. None of the above
4) Which molecule contains a double bond?
b. C2H6
c. CF4
a. COCl2
d. SF2
5) What is the hybridization of the carbon atom in CH4?
a. sp
b. sp2
c. sp3
d. none of these
6) Chemical bonding in metals is
a. The same as ionic bonding
b. The same as covalent bonding
c. A combination of ionic and covalent bonding
d. Different from ionic or covalent bonding
7) Which of the following properties is not explained by metallic bonding?
a. Electrical conductivity
b. Thermal conductivity
c. Brittleness
d. Ductility
8) Orbitals of equal energy produced by the combination of two or more orbitals on
the same atom are called
a. Bonding orbitals
b. Valence orbitals
c. Hybrid orbitals
d. High-energy orbitals
9) A long chain of amino acids is
a. Lipid
b. Protein
c. Carbohydrate
d. Nucleic acid
10) Composed of a phosphate, sugar, and nitrogen base
a. Fatty acid
b. Amino acid
c. Monosaccharide
d. Nucleotide
11) Class of macromolecules that includes phospholipids and steroids
a. Lipid
b. Protein
c. Carbohydrate
d. Nucleic acid
12) Which of the following statements about bonding is correct?
a. Van der Waals forces exist between polar molecules
b. Dipoles are the result of the equal sharing of electrons
c. Cu(s) is a network solid
d. Hydrogen bonds exist between molecules of HCl
e. NaCl(aq) has attraction between the molecules and the ions
13) If a chemist calculates the maximum amount of product that could be obtained
in a chemical reaction, he or she is calculating the
a. Percentage yield
b. Mole ratio
c. Theoretical yield
d. Actual yield
14) Which of the following atoms has six valence electrons?
a. magnesium (Mg)
b. silicon (Si)
c. sulfur (S)
d. argon (Ar)
15) Results of Firing Alpha Particles at Gold Foil
Observations
Proportion:
Alpha particles went straight through
gold foil.
Alpha particles went through gold foil
but were deflected at large angles.
Alpha particles bounced off gold foil.
>98%
≈2%
≈0.01%
What information do the experimental results above reveal about the nucleus of
the atom?
a. The nucleus contains less than half the mass of the atom.
b. The nucleus is small and is the densest part of the atom.
c. The nucleus contains small positive and negative particles.
d. The nucleus is large and occupies most of the atom’s space.
16) Why are enormous amounts of energy required to separate a nucleus into its
component protons and neutrons even though the protons in the nucleus repel each
other?
a. The force of the protons repelling each other is small compared to the
attraction of the neutrons to each other.
b. The electrostatic forces acting between other atoms lowers the force of
repulsion of the protons.
c. The interactions between neutrons and electrons neutralizes the repulsive
forces between the protons.
d. The forces holding the nucleus together are much stronger than the
repulsion between the protons.
17) The most abundant isotope of lead contains 82 protons and 124 neutrons packed
closely together in the nucleus. Why do the protons stay together in the nucleus
rather than fly apart?
a. Electrons in neighboring atoms neutralize repulsive forces between
protons.
b. Neutrons effectively block the protons and keep them far apart to
prevent repulsion.
c. Electrostatic forces between neutrons and protons hold the nucleus
together.
d. Nuclear forces overcome repulsive forces between protons in the nucleus.
18) Which statement is inconsistent with the concept of isotopes of the same
element?
a. Isotopes have the same number of protons
b. Isotopes have the same atomic number
c. Isotopes differ in mass number
d. Isotopes differ in number of neutrons present
e. Isotopes differ in their nuclear charge
19) When cations and anions join, they form what kind of chemical bond?
a. ionic
b. hydrogen
c. metallic
d. covalent
20) Which of the following correctly shows how carbon and hydrogen bond to form
a compound?
a. [4H]+4[C]-4
b.
c. [H]+[C]-
d. C-H
21) Some of the molecules found in the human body are NH2CH2COOH (glycine),
C6H12O6 (glucose), and CH3(CH2)16COOH (stearic acid). The bonds they form are
a. nuclear
b. metallic
c. ionic
d. covalent
22) What type of force holds ions together in salts such as CaF2?
a. electrostatic
b. magnetic
c. gravitational
d. nuclear
23) Which substance is made up of many monomers joined together in long chains?
a. salt
b. protein
c. ethanol
d. propane
24) Which element is capable of forming stable, extended chains of atoms through
single, double, or triple bonds with itself?
a. carbon
b. oxygen
c. nitrogen
d. hydrogen
25) Fe2O3 + 3CO → 2Fe + 3CO2
In this reaction, how many grams of Fe2O3 are required to completely react with 84
grams of CO?
a. 64 g
b. 80 g
c. 160 g
d. 1400 g
26) Mg3N2 + 6H2O → 2NH3 + 3Mg(OH)2
If 54.0 grams of water are mixed with excess magnesium nitride, then how many
grams of ammonia (NH3) are produced?
a. 1.00 g
b. 17.0 g
c. 51.0 g
d. 153 g
27) A mass of 5.4 grams of aluminum (Al) reacts with an excess of copper (II)
chloride (CuCl2) in solution, as shown below.
3CuCl2 + 2Al → 2AlCl3 + 3Cu
What mass of solid copper (Cu) is produced?
a. 0.65 g
b. 8.5 g
c. 13 g
d. 19 g
28) Nuclear reactions are recognized by changes in an atom’s
a. mass number and/or nuclear charge
b. number of electrons
c. ionic charges
d. bonding capacity
29) How many neutrons are present in an atom of tin that has an atomic number of
50 and a mass number of 119?
a. 50
b. 119
c. 69
d. 169
Problems (3 points each)
Draw Lewis Structures for the following molecules. Show resonance structures, if
they exist.
1) CO
2) PCl3
3) NO3-
Draw a Lewis Structure for each of the following molecules, and then use the
VSEPR theory to predict the hybridization and the molecular structure of each:
4) SCl2
hybridization =
molecular structure=
5) NH2Cl
hybridization =
molecular structure =
6) Write a balanced equation for the nuclear reaction in which Ga-73 produces a βparticle.
7) Write a balanced equation for the nuclear reaction in which Uranium-235
produces an α-particle.