Honors Biology-
Chemistry Review: Campbell Ch 2-3
1. Complete the following conversions:
5.65 g = 0.00565 kg
0.056 m = 56 mm
174 mL =0.174 L
711 kg = 711,000 g
3.79 km = 3790 m
0.006 L = 6000 μL
0.074 g = 74 mg
745 μm =0.0745 cm
127 μL =0.127 mL
302°C = 575 K
185 K =
100°C =
-88 °C
373 K
2. Express the following measurements in scientific notation:
246.983 = 2.46983 x 102 17.2 = 1.72 x 101
0.06713 =6.713 x 10-2
0.00053 = 5.3 x 10-4
150 = 1.5 x 102 100,005 = 1.00005 x 105
132,987,000 = 1.32987 x108
0.3 = 3 x 10-1
3. Round each of these measurements to three significant figures:
24.590 = 24.6
67.963 = 68.0
24.353 = 24.4
102.06 =102
3.002 =
102.6 =
3.00
103
956.789 = 957
99.88 =
99.9
4. A block of rock salt has a mass of 10.7 g. Each edge of the block has a
length of 5.00 cm. What is the density of the rock salt?
m= 10.7g
v= 125cm3
D= m/v
D= 0.0856g/cm3
5. Indicate whether the substances below are compounds or elements:
SO2: C
S8:
E
C60: E
He: E
N2:
E
NaCl:
CH4: C
C
H2O: C
6. What is an isotope? Same element but different number of neutrons
(results in a different mass number)
7. What is the octet rule? Explain its relationship to chemical bond
formation.
Atoms will share, gain, or lose electrons in order to be stable (have a
complete valence); this process involves either covalent or ionic bonds.
8. Complete the table below:
Isotope
Symbol # of
protons
6
Carbon-12
6
Carbon-14
50
Tin-119
50
Tin-120
26
Iron-56
3
Lithium-7
11
Sodium-23
# of
electrons
6
# of
neutrons
6
Atomic
#
6
Mass #
12
6
8
6
14
50
69
50
119
50
70
50
120
26
30
26
56
3
4
3
7
11
12
11
23
9. Explain why atoms of the noble gases do not easily form bonds, unlike most
other atoms.
They have a full valence already and are stable.
10.
Ca+2
Xe
O-2
Rb+1
I-1
N-3
11. Write the chemical formulas for the ionic compounds formed from the
following:
A) magnesium and iodine: MgI2
C) sodium and sulfur Na2S
B) Fe3+ and oxygen: Fe2O3
D) Pb2+ and nitrogen: Pb3N2
12. What is the difference between a nonpolar covalent bond and a polar
covalent bond?
In a nonpolar covalent bond, atoms are approximately equal in
electronegativity & neither atom pulls the electrons more towards them;
in a polar covalent bond, one of the atoms pulls the shared electrons
towards them more.
13. What is a hydrogen bond? A weak bond between a slightly negative
atom & a slightly positive atom of different molecules.
14. Depict the hydrogen bond formed between:
A) two water molecules
∂-
∂-
∂+
B) a water molecule & an ammonia (NH3) molecule
15. Balance the following equations:
A) CH4 +
2 O2  CO2 +
∂+
∂-
∂+
∂-
2 H2O
∂+
B)
2 Sb +
3 I2 
2 SbI3
C)
3 H2 +
N2

2 NH3
D)
6 CO2
+
6 H2 O

∂+
C6H12O6
+
6 O2
∂+
16. Determine the molar mass (g/mol) of the following compounds:
A) CO2
44g/mol
C) C6H12O6
180g/mol
B) NaCl 58.5g/mol
D) H2CO3
62g/mol
17. How many grams of lactic acid (C3H6O3) are in 1 L of a 0.5 M solution of
lactic acid?
(1L) (.5mol/L) (90g/mol) = 45g (units cancel)
18. How many grams of salt (NaCl) must be dissolved in water to make 2 liters
of a 2.0 M salt solution? (2L) (2mol/L) (58.5g/mol) = 234g
19. What causes a solution to become acidic? Increase in hydrogen ion
concentration of a solution
Basic? Reduction of hydrogen ion concentration of a solution
Neutral? Equal #’s of H+ and OH- ions
20. What does the pH scale measure? Concentration of H+ and OH- in a
solution.
21. Describe how buffers help to maintain the pH of solutions and why this
would be important in living organisms.
Buffers help to maintain the pH of solutions by accepting or donating
hydrogen ions from the solution when they are in excess or have been
depleted.
22. Define the following terms which apply to solutions:
A) solute: dissolved by solvent
B) solvent: dissolving agent of a solution
C) aqueous solution: solution where water is the solvent
D) hydrophilic: water loving
E) hydrophobic: water “fearing” (won’t dissolve in water or other polar
solvents)
23. Indicate whether the following compounds are hydrophilic or
hydrophobic. Do these substances contain ionic, polar, or nonpolar bonds?
A) olive oil: hydrophobic; nonpolar
B) sugar: hydrophilic; polar
C) salt: hydrophilic; ionic
D) candle wax: hydrophobic; nonpolar
24. Complete the following concept map illustrating how hydrogen bonding in
water contributes to temperature regulation.
a) water molecule
b) absorbed
c) released
d) specific heat
e) heat of vaporization
f) evaporative cooling
g) solar energy/ heat
h) rain clouds
i) ice
25. List the 4 major classes of macromolecules.
Lipid, Protein, Carbohydrate, Nucleic Acid
26. What is a monomer? Small molecule that serves as a building block for
a polymer
What is a polymer? Large molecule consisting of many similar identical
building blocks linked by covalent bonds
27. Describe how a number of individual cars linked together forming a train
is an appropriate analogy for the formation of a macromolecule.
Individual cars represent the monomers which are linked (or bonded)
together to form a long molecule (train or polymer)