CHM 100                        Quiz 1                        Fall, 1998

1.  “Trans” fatty acids are grouped with “unsaturated” fats as foods which may be harmful to health.  Which of the following is a statement about the chemistry of trans fatty acids?

a.  The trans fatty acid, stearic acid, has a melting point of 72 ^oC.

b.  Margarines contain 11-49% trans fatty acids.

c.  The predominant source of dietary trans fatty acids is the partially hydrogenated vegetable oil used in producing cooking fats and margarines.

d.  Resident bacteria in the digestive tract of ruminant animals like cows can produce trans fatty acids.

e.  Trans-fatty acids have one or more double bonds between carbon atoms in which the adjacent hydrogen atoms are on opposite sides of the chain, making them linear like saturated fats.

2.  Which of the following can be separated into two or more elements only by a chemical process?

a.  sulfur        b.  hydrogen        c.  iodine        d.  nitrogen        e.  baking soda

3.  How should the number that results from the division 8.00 x 10^-401/ 4.00 x 10^-398 be expressed as a floating point (decimal) number?

a.  0.0200        b. 0.00200        c. 0.000200        d.  2.00 x 10^-799        e.  some other value.

4.How many significant figures are in the value 0.00340 mL?

a. 6        b. 5        c.  4        d.  3        e.  2

Questions 5 and 6 refer to a portion of the scale of a graduated cylinder containing some liquid, shown at the right.

5.What is the correct way to record the volume, according to the rule we adopted?

a.  20.6 mL        b.  26 mL        c.  26.0 mL        d.  2.0 x 10¹ mL        e.  none of these

6.Which is the accepted estimate of the random error in the measurement?

a.  0.005 mL        b.  0.05 mL        c.  0.5 mL        d.  1 mL        e.  1.5 mL

7.What is the correct number of significant figures in the product 2.0 x  345.8?

a.  1        b.  2        c.  3        d.  4        e.  5

8.What is the correct number of significant figures in the sum 24.0730 g + 4.0 g?

a.  2        b.  3        c. 4        d.  5        e.  6

9.What is the density of a substance in g/cm³ if 20.0 in³ weighs 0.860 lbs?  1 in  = 2.54 cm; 1 lb = 454 g.

a.  1.19         b.  4.87        c.  3.02        d.  5.81        e.  7.68

10.How many protons, neutrons, and electrons are in the species ²⁴₁₁Na⁺?

         n        p        e

a.    24      11        10

b.    24        13        10

c.     24        11        12

d.        13        11        12

e.        13        11        10

11.Given the nuclear equation ²⁰⁷₈₄Po     -->    ²⁰⁷₈₃Bi + ???, what is the other product?

a.  beta        b.  positron        c. alpha        d.  gamma        e.        neutron