120 Exam 1 Sp10

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					Grossmont College                                       Name _____________________________
Chemistry 120
Spring 2010                                             Lab Day___________ Date ____________

                                                  Exam 1

Part I: Multiple Choice (2 points each)
Directions: Please circle the best answer for each of the following questions.

Question 1.     Which of the following changes             Question 6.    Which metric system prefixes
                 is/are classified as chemical?                           is correctly paired with its
               a) Dissolving vinegar in water                             mathematical meaning?
               b) Evaporation of rubbing alcohol                          a) milli- and 10-2
               c) Crushing rock                                           b) micro- and 10-6
               d) Fermenting apple juice                                  c) giga and 10-9
               e) Softening a glass tube by                               d) deci and 105
                    heating it                                            e) kilo and 101

Question 2.        ______ two substances                   Question 7.    What color is sulfur?
                   present, two phases present.                           a) brown
                                                                          b) red
                   a)   Heterogeous mixture
                                                                          c) yellow
                   b)   Homogeneous mixture
                                                                          d) blue
                   c)   Pure substance
                                                                          e) gray
                   d)   Compound
                   e)   Atom
                                                           Question 8.     Most methods for separating
                                                                           mixtures into their components
Question 3. The melting point of iron is
                                                                           depend on differing
            1535˚C. What is the Fahrenheit
                                                                           ____________ among the
            equivalent of this temperature?
            a) 821˚F
                                                                          a) physical properties
            b) 885˚F
                                                                          b) chemical properties
            c) 2731˚F
                                                                          c) electromagnetic properties
            d) 2795˚F
                                                                          d) normalized properties
            e) 2821˚F
                                                                          e) spectroscopic properties
Question 4.     _____ symbol/name pairs is/are
                                                           Question 9.    Identify x in HxPO4, given that
              correctly matched.
                                                                          molecules of the compound
               a) Fl, Fluorine
                                                                          contain eight atoms?
               b) N, Neon
                                                                          a) one
               c) S, Sodium
                                                                          b) two
               d) Ch, Chlorine
                                                                          c) three
               e) H, Hydrogen
                                                                          d) four
                                                                          e) not enough information
Question 5. Which of the following statements
            contain an exact number?
                                                           Question 10.   Name the piece of equipment:
            a) There are 63 apples in the box.
            b) The magazine has 24 pages.
            c) The paper dimensions are 8.5 x
                11 inches
            d) all of the above
            e) none of the above

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Chemistry 120                                                                  Exam 1
Vance                                                                          Spring 2010

Part II: Short Answer
Directions: Answer each of the following questions. Be sure to use complete
sentences where appropriate. For full credit be sure to show all of your work.

Question 1.     Arrange the following steps in the scientific method in the sequence in
                which they normally occur (10 points).
                a.     Suggest probable explanations for generalizations obtained from
                b.     Collect data concerning a problem through observation and
                c.     Identify a problem, and carefully plan procedures to obtain
                       information about all aspects of this problem.
                d.     Experiment further to prove or disprove explanations.
                e.     Analyze and organize data in terms of general statements that
                       summarize experimental observations.

Question 2.    Classify each of the following as macroscopic, microscopic, or particulate
              (4 points)

                a. Tree                                              __________________

                b. Plant cell                                        __________________

                c. Protein molecule                                  __________________

                d. Electron                                          __________________

Question 3.     In the following pairs of numbers, tell whether both members of the pair
                have an uncertainty of less than ± 0.01 (4 points)

                a. 0.006 and 0.016                                                  ______

                b. 2.700 and 2.700 x 102                                            ______

                c. 3300.00 and 33                                                   ______

                d. 5.750 x 101 and 5.750 x 10-1                                     ______

Question 4.     Describe the proper procedure for heating a solution in test tube with a
                flame (3 points).

                                        Page 1 of 4
Chemistry 120                                                                  Exam 1
Vance                                                                          Spring 2010
Question 5.     Bronze is 80.0% by mass copper, and 20.0% by mass tin. A sculptor is
                preparing to cast a 1.75 lb bronze figure. How many kg of copper does he
                need (10 points)?

Question 6.     Write the complete chemical symbol (      ) for atoms with the following
                characteristics (12 points).
                a. A neutral atom containing 20 electrons and 24 neutrons

                b. Oxygen atoms with a mass number 17

                c. Silver atom that contains 157 subatomic particles in the nucleus

                d. Beryllium atom that contains 2 electrons and 5 neutrons.

Question 7.     Correct the following chemical formulas (8 points).

                a. CACO3                                                    ____________

                b. Na2Cl2                                                   ____________

                c. Hi (aq)                                                  ____________

                d. 2HO                                                      ____________

Question 8.     The density of air at ordinary atmospheric pressure and 25 °C is 1.19 g/L.
                What is the mass, in kilograms, of the air in a room that measures 12.5 ft x
                15.5 ft x 8.0 ft (8 points)?

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Chemistry 120                                                                   Exam 1
Vance                                                                           Spring 2010
Question 9.     Are the following statements true or false? If incorrect, please correct the
                mistake (9 points).

          __________           a. Safety goggles/glasses only need to be worn if you are
                                   working directly with chemicals or flames.

          __________           b. Weighing something when it is hot will give you the
                               same value as if it was room temperature.

          __________           c. If you spill acid or base on the benches you should
                               neutralize it with sodium bicarbonate and wash the area
                               with water.

          __________           d. Reagent caps and coin top stoppers may be placed on
                               the bench tops when measuring out chemicals.

          __________           e. If you are dropped by the instructor you do not have to
                                  check out of your lab drawer.

Question 10. Given the following distribution of isotopes (12 points):
               5.8%                                         53.9396 u
             91.8%                                          55.9349 u
              2.1%                                          56.9354 u
             0.3%                                           57.9333 u

                a. Calculate the atomic mass of the element

                b. What is the identity of the element?                      ____________

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