Chemistry 112
Quiz 1A - E
Harwood/Fall 04
KEY
Quiz 1A
1. The element oxygen has three naturally occurring isotopes of masses 16, 17, and 18. Describe the
similarities and differences between the three kinds of atoms of oxygen.
(6 pts)
16
The numbers of protons and electrons are the same (8). The number of neutrons differs. O
17
18
has 8 neutrons, O has 9 neutrons, and O has 10 neutrons. Having different numbers of
neutrons will make the masses of the isotopes different.
2. The density of chloroform, a widely used organic solvent, is 1.4832 g /mL at 20°C. How many
milliliters would you use if you wanted 112.5 g of chloroform? Express your answer with the correct
number of significant figures. Volume = (112.5 g)(1 mL / 1.4832 g) = 75.85 mL (6 pts)(-1 for sig figs)
3. Indicate where in the periodic table (in general) the following elements are found:
(4 pts each)
a. Elements that commonly form anions. Right side of the periodic table.
b. Elements that commonly form cations. Left side of the periodic table.
Quiz 1B
1. Same as 1A.
(6 pts)
3
2. Aspirin has a density of 1.40 g/cm . What is the volume (in cubic centimeters) of an aspirin tablet
weighing 250 mg? Volume = (0.250 g)(1 cm3 / 1.40 g) = 0.179 cm3
(6 pts)(-1 for sig figs)
3. Indicate where in the periodic table (in general) the following elements are found:
(4 pts each)
a. Metallic elements. Left side of the periodic table.
b. Nonmetallic elements. Right side of the periodic table.
Quiz 1C
1. Same as 1A.
(6 pts)
2. Gaseous hydrogen has a density of 0.0899 g/L at 0°C. How many liters of hydrogen would you need
if you wanted 1.0078 g of hydrogen? Volume = (1.0078 g)(1 L / 0.0899 g) = 11.2 L(6 pts) (-1 for sig figs)
3. List 2 alkali metals. Any two of Li, Na, K, Rb, Cs, Fr will be fine.
(4 pts each)
Quiz 1D
1. Same as 1A.
(6 pts)
2. The density of gaseous chlorine is 3.214 g/L at 0°C. How many liters would you need if you wanted
35.45 g of chlorine? Volume = (35.45 g)(1 L / 3.214 g) = 11.03 L
(6 pts) (-1 for sig figs)
3. List 2 alkaline earth metals. Any two of Be, Mg, Ca, Sr, Ba, Ra will be fine.
(4 pts each)
Quiz 1E
1. Same as 1A.
(6 pts)
3
2. Aspirin has a density of 1.40 g/cm . What is the volume (in cubic centimeters) of an aspirin tablet
weighing 500. mg? Volume = (0.500 g)(1 cm3 / 1.40 g) = 0.357 cm3
(6 pts) (-1 for sig figs)
3. Give the names corresponding to the following symbols:
a. Mg
magnesium
b. Fe
iron
(4 pts each)