UNIT 2 TEST REVIEW
1. Know all definitions on your “foldable”.
2. Which of the following are chemical changes and which are physical changes?
a. melting iron PHYSICAL
e. burning hydrogen CHEMICAL
b. rusting iron
f. crystallization
PHYSICAL
g. tearing paper
PHYSICAL
CHEMICAL
c. decomposition of H2O2 CHEMICAL
d. exploding dynamite CHEMICAL
h. evaporating salt water PHYSICAL
3. Identify each of the following as being elements, compounds, homogeneous mixtures (solutions) or
heterogeneous mixtures.
a.
iron
ELEMENT
h. pool water HOMO. MIXTURE
b.
dirt
HETERO. MIXTURE
c.
hydrochloric acid (HCl)
d.
salt water
e.
Italian salad dressing HETERO. MIXTURE l. playdoh
HOMO. MIXTURE
f.
lemonade
MIXTURE **
m. granite
HETERO. MIXTURE
g.
mercury (Hg)
ELEMENT
n. tap water
HOMO. MIXTURE
COMPOUND
HOMO. MIXTURE
i. sugar
COMPOUND
j. apple juice HOMO. MIXTURE
k. maple syrup HOMO. MIXTURE
** it would be HOMOGENEOUS if it was mixed from powder; it would be HETEROGENEOUS if it was
made fresh and had pulp.
4. Explain the difference between a homogeneous mixture (solution) and a heterogeneous mixture.
Heterogeneous Mixture : A mixture that does not blend smoothly throughout
Homogeneous Mixture: A mixture that has constant composition throughout
5. What are seven indicators of a chemical reaction?
1. A gas has been produced (bubbles); 2. A change in color;
3. A change in temperature; 4. A precipitate forms (new solid forms);
5. Light is produced; 6. New odor; 7. Explosion
REVIEW FROM CHAPTERS 1 AND 2 TEST: Use the correct number of significant figures
6. What is the volume of an object with a density of 5.70 g/mL and a mass of 15.28 g?
V = m/D = 15.28 g / 5.70 g/ml = 2.68 mL (3 sig figs)
7. What is the volume of an object whose density is 0.75 g/mL and who mass is 1.45 g?
V = m/D = 1.45 g / 0.75 g/ml = 1.9 mL (2 sig figs)
8. What is the mass of an object whose density is 10.02 g/mL and whose volume is 35 mL?
m = D x V = 10.02 g/mL x 35 mL= 350 g (2 sig figs)
9. What is the density of an object with a volume of 0.51 mL and a mass of 2.4 g?
D= m/V = 2.4 g / 0.51 mL = 4.7 g /mL (2 sig figs)
10. Use the graph to the right to determine the density of substance K, L, M, and N. Assume the mass units
are grams (g) and the volume units are milliliters (mL).
Density = slope of line=
K:
L:
M:
N:
(
)
(
)
(
)
(
)
(
)
(
)
(
)
(
)
= 3 g/mL
= 1.5 g/mL
= 0.67 g/mL
= 1 g/mL
(pick any 2 points on the line)
11. Metric Conversions:
Write the prefixes (“King Henry….”)
King Henry
Died
By
Drinking
Chocolate
Milk
kilo
hector
deca
base
deci
centi
milli
k
h
da
d
c
m
a. 23 mg = ____0.023___ g
3 places to the left
b. 1.92 km = ____19200___ dm
4 places to the right
c. 455 mL = ___0.0455__ daL
4 places to the left
d. 0.085 g = _____8.5___ cg
2 places to the right
e. 6800 cm = _____68____ m
2 places to the left
f. 24500 ms = ____245___ ds
2 places to the left