Chemistry 121
Quiz I Practice
Winter 2017
The following quiz contains 21 questions valued at 1.0 point/question
Name KEY
Density (ethanol) = 0.789 g/ml
1 yd = 3 ft
2.54 cm/in
36 inches = 1 yard
453.6 g = 1 lb
kg = 2.205 lb
meter = 39.37 inches
1 mile = 1.609 km
1 fl.oz. = 29.57 mL
1. Which of the following is a physical change and which is a chemical
change? Use PC for physical change or CC for chemical change.
a. Boiling water
PC
b. Decomposing water by passing electric current through it
c. Dissolving sugar in water
CC
PC
d. Exploding of potassium metal when placed in water
CC
2. Which of the following best describes mayonnaise?
a. Heterogeneous mixture
b. Homogeneous mixture
c. Compound
d. Element
3. Which of the following best describes chunky salsa (the food not the
dance)?
a.
b.
c.
d.
A
A
A
A
homogenous element
homogeneous compound
heterogeneous element
heterogeneous compound
e. A heterogeneous mixture
4. Which of the following defines a colloidal dispersion?
a. Particle size  2 Å
b. Particle size  2 nm
c. 2 nm  particle size  .5 m
d. Particle size  .5 m
5. Please provide the name for a colloidal dispersion of a liquid dispersed
into a gas
Answer: [Liquid] Aerosol
6. Which of the following is the symbol for sodium
a.
b.
c.
d.
S
So
Si
Ni
e. Na
Bonus (1 EC): Which of the above symbols does not correspond to any
element?
Answer: So
S = sulfur, Si = silicon, Ni = nickel, So = a needle pulling thread
7. Please provide the symbols for the following elements
a. Argon Ar
b. Arsenic As
8. Give the names corresponding to the following symbols
a. Xe Xenon
b. Kr Krypton
(warrior element)
9. How many g (mcg) are equivalent to a mg?
a. 106 g/mg
b. 103 g/mg
c. 10-3 g/mg
d. 10-6 g/mg
Micro is 1000x smaller than milli so you would need 1000 of them for the same
quantity
10. How many km are equivalent to a mm?
a. 1.0 x 106 km/mm
b. 1.0 x 103 km/mm
c. 1.0 x 10-3 km/mm
d. 1.0 x 10-6 km/mm
Kilometer is 1000x larger than the meter, which in turn is 1000x larger than
millimeter, so you would need 0.000 001 of the kilometer to correspond to a mm
11. 4 scales were tested against a 5.000 g mass standard. Of the following
sets of measurements, which has the greatest accuracy?
Scale 1
4.888 g
4.887 g
4.886 g
4.887 g
Scale 2
5.020 g
5.010 g
4.980 g
4.990 g
Scale 3
5.000 g
5.122 g
5.266 g
5.034 g
Scale 4
3.967 g
4.323 g
5.855 g
5.855 g
a. Scale 1
b. Scale 2
c. Scale 3
d. Scale 4
Scale 2 is consistent with the standard to 2 significant figures
12. How many significant figures are in 0.0071 g?
a. 1
b. 2
c. 3
d. 4
e. 5
13. Express 0.0071 g in scientific notation.
Answer: 7.1 x 10
-3
g
Notice the 2 significant figures in the lead term
14. Express 0.0071 g using the appropriate metric prefix.
Answer: 7.1 mg
milli = 10-3
15. Please carry out the following calculation, retaining the correct number of
significant figures and showing units.
(2.231 g + 1.00 g + 4.2294 g)  7.1 mL
2.231?
1.00??
4.2294
7.4604  7.04 g
7.04 g ÷ 7.1 mL
Answer: 0.99 g/mL
16. A metric ton is 1000 kg. A British ton is 2000 pounds. What is the
difference in mass between a British and metric ton?
a. 2.2 pounds
b. 200 pounds
c. 220 pounds
d. 1000 pounds
1000 kg(2.205 lb/kg) = 2,205 lb
2,205 lb – 2000 lb = 205 lb
17. The mass of premature babies is customarily determined in grams. If
a premature baby weighs 1550 g, what is its mass in pounds? Please
show your work.
1550 g(lb/453.6 g) = 3.42 lb
18. An individual weighs 83.2 kg and is 1.92 m tall. What are the person’s
equivalent measurements in pounds and feet? Please show your work.
83.2 kg(2.205 lb/ft) = 183 lb
1.92 m(39.37 in/m)(ft/12 in) = 6.30 ft or 6’4”
19. Which is a longer race, the 800 m (exactly) or the half mile (0.5 mile
exactly)? Please show your work.
0.500 mi(1609 m/mi) = 804 m 804 m > 800 m
20. What is the mass associated with 50.0 mL pure ethanol?
a. 0.789 g
b. 39.4 g
c. 50.0 g
d. 63.4 g
50.0 mL(0.789 g/mL). As a mental check, if the density were 1.00 g/mL it
would weigh 50 g and the density is less, so the mass should be less
21. Ethanol (CH3CH2OH) has a molar mass = 46 g/mole. How many grams of
ethanol are required for 2.0 mol of ethanol?
a. 2.3 g
b. 9.2 g
c. 23 g
d. 92 g
2.0 mol(46 g/mol).
Bonus (1 EC): Mercury has a density of 13.6 g/mL at 20 oC. What is the mass
in pounds of one U.S. pint (16 fl. oz. exactly) of mercury? Please show your
work.
16.0 fl oz(29.57 mL/fl. oz)(13.6 g/mL)(lb/453.6 g) = 14.2 lb