End of Chapter: Numerical Side of Chemistry
Supplemental Instruction
Iowa State University / Leader: / Kara
Course: / Chem 163
Instructor: / Sadow or Woo
Date: / 9/9/13
Study Tip of the Day: Most of the time the thought of the exam is scarier than the actual exam. But nerves are what help you study more and really kick it in gear. So embrace the nerves with an assurance that you’re probably more nervous than you need to be but on the right track!
1. Carry out the following conversions:
(a) How many grams of meat are in a quarter-pound hamburger (0.25 lb) ? (1 lb = 453.5924g)
(b) How tall (in meters) is the Sears Tower in Chicago (1454 ft) ?
(1 ft = 0.3048 m)
2. Amounts of substances dissolved in solution are often expressed as mass per unit volume. For example, normal human blood has a cholesterol concentration of about 200 mg / 100 mL. Express this concentration in the following units:
(a) mg/ L
(b) g/ L
3. Aspirin has a density of 1.40 g/cm3 . What is the volume (in cubic centimeters) of an aspirin tablet weighing 250 mg?
4. When an irregularly shaped chunk of silicon weighing 8.763 g was placed in a graduated cylinder containing 25.00 mL of water, the water level in the cylinder rose to 28.76mL. What is the density of silicon in g/cm3?
5. What is the diameter of a single iron atom in meters if it’s diameter is 1.4 x 10-4 µm?
6. What is the volume of 7.20 lbs of gouda cheese in liters? 1 pound is 454 g. The density of gouda cheese is .10 g/cm3.
7. Solve the following problems with correct significant figures!
23.71 52.275 1.67 x 102
x14.2 .6969 + 3.4 x 102
(10.45-27.2)/.684 1.67 x 10-4
+3.4 x 10-6
5.48 x 1010 (.020+4.56) x ((1.29 x 10-3) –(3.99/2.045))
x6.745 x 108
8. Solve each problem and answer with correct number of significant figures:
(c)4.10 x 302−1100/1.56x10-4 (f) 5.19x10–2+ 1.83 + 219