Download Intensive Set Chapter 2

Intensive Set Chapter 2
Basic
1. If an atom contains 16 protons and 18 neutrons, what is its mass number? Write the
shorthand representation for that atom and name it.
2.
If a neutral atom has a mass number of 13 and an atomic number of 6, how many
protons, neutrons, and electrons are in that atom? Write the shorthand representation
for that atom and name it
3. Natural oxygen consists of 99.76% 16O (15.9949 u), 0.0400% 17O (16.9991 u) and
0.02000% 18O (17.9992 u). What is the average atomic mass of oxygen?
4. Calculate the average atomic mass of magnesium. Magnesium consists of three
isotopes: 24Mg = 23.985 u with a percent abundance of 78.99%, 25Mg = 24.986 u
with a percent abundance of 10.00%, the rest is 26Mg = 25.983 u.
5. Write the molecular and empirical formulas of each of the following compounds:
a. an organic compound, heptanol, has 7 carbon atoms , 16 hydrogen atoms, and 1
oxygen atom
b. Vitamin C, ascorbic acid, has six carbon atoms, eight hydrogen atoms, and six
oxygen atoms
c. Aspartane, an artificial sweetener, has 14 carbon atoms, 18 hydrogen atoms, and 5
oxygen atoms
6. Give the total number of atoms in TNT, C6H2CH3(NO2)3 and in Ge[S(CH2)4CH3]4.
7. Which of the following are correct formulas for ionic compounds? For those that are
not, give the correct formula.
a. Ca2O
b. SrBr2
c. Li2O
8. Write formulas for the ionic compounds that can be formed by combining the cations,
NH4+, Ni+2 with the anions CO3-2, SO4-2.
9. Give an example of each of the following:
a.
b.
c.
d.
e.
f.
g.
halogen
transition metal
noble gas
nonmetal
lanthanide
alkaline earth metal
actinide
h. metalloid
i. alkali metal
Involved
1. Name the following ions.
CN-
____________________
NO2-
____________________
PO43-
____________________
OH-
____________________
NH4+
____________________
2. Name the following compounds
Na2S
____________________
BF3
____________________
H3PO4(aq)
____________________
SO2
____________________
Mg3(PO4)2
____________________
N2O5
____________________
LiNO3
____________________
HCl(aq)
____________________
KMnO4
____________________
P4S3
____________________
3. Write formulas for the following compounds.
Tin (II) chloride
____________________
Nitric acid
____________________
Sulfur hexafluoride
____________________
Lithium phosphide
____________________
Barium sulfate
____________________
Titanium (IV) oxide
____________________
4. Show that the following experiment is consistent with the law of conservation of
mass (within the limits of experimental error): A 10.00 g sample of calcium
carbonate was dissolved in 100.0 mL of hydrochloric acid solution (d = 1.148 g/mL).
The products were 120.40 g of solution and 2.22 L of carbon dioxide gas (d =
0.0019769 g/mL).
5. Antimony has two stable isotopes, 121Sb and 123Sb, with masses of 120.9038 u and
122.9042 u respectively. Calculate the percent abundances of each of these isotopes.
6. Fill in the table
Symbol
Number of
protons
Number of
neutrons
Number of
electrons
10
10
30
25
Name of the
atom
58
Ni
S
33
Challenging
1. The table below gives numbers of electrons, protons, and neutrons in atoms or ions of
elements represented by A, B, C, …. Answer the following using the table:
a. Which of the species are neutral?
b. Which are negatively charged?
c. Which are positively charged?
d. Use the shorthand discussed in class to represent each of the species.
A
B
C
D
E
F
G
Number 5
10
18
28
36
5
9
of
electrons
Number 5
7
19
30
35
5
9
of
protons
Number 5
7
20
36
46
6
10
of
neutrons
2. One isotope of a nonmetallic element has a mass number of 127 and 74 neutrons in
the nucleus. The anion derived from this isotope has 54 electrons. Write the symbol
for the anion.
3. Consider an atom of 64Zn.
a. Calculate the density of the nucleus in g/cm3, knowing that the nuclear diameter is
9.6 x 10-6 nm and the mass of the 64Zn nucleus is 1.06 x 10-22 g. Recall that the
volume of a sphere is (4/3)r3.
b. Using the same formula for volume, calculate the density of the space occupied
by the electrons in the zinc atom in g/cm3, given that the atomic radius is 0.125
nm and the electron mass is 9.11 x 10-31 kg.
c. Having calculated the previous densities, what statement can you make about the
relative densities of the parts of the atom?