Department of Chemistry, Geosciences and Environmental Sciences

 

                                                                     Exam 4-A-Key

                       

Chemisty 1084:  Section 010                                                                                       Fall 2006

 

Name:________________________________________________________

 

Read all directions and questions carefully!!  This exam consists of two parts.  The first part consists of 10 multiple choice questions worth four points each for a total of 40 points.  The second part consists of five numerical problems worth either 10 or 15 points per question for a total of 60 points.  Show all your work necessary for the numerical problems as partial credit will be given for those problems.

 

Possibly Useful Constants and Equations

 

     Radioactive decay rates: 

     E = mc2                                                                        1 amu = 1.6605 × 10-27 kg

     c = 2.998 × 108 m/s

 

 

Score

 

                                    Part 1 (40 points):_____________________

 

 

                                    Part 2 (60 points):_____________________

 

 

                                    Total (100 points):_____________________

 

 

Don’t forget to put your name on this test!

 

Good Luck!!

Part 1

 

Multiple Choice

 

Please indicate the answer to each question by putting your choice in the space provided.  There is only one correct answer for each question.  There will be 10 multiple choice questions worth 4 points each.

 

1.  The smallest number of stable isotopes have an _____________ number of protons and an ___________ number of neutrons.

       (a)  even, even                                                            (c)  even, odd

       (b)  odd, even                                                             (d)  odd, odd

 

Answer:  D

 

2.  Which type of reaction is known as a thermonuclear reaction?

       (a)  fission                                                                  (c)  fusion

       (b)  transmutation                                                        (d)  beta emission

                                          (e)  neutron emission

 

Answer:  C

 

3.  Which type of radiation causes the most damage to living tissue?

       (a)  alpha                                                                    (c)  gamma

       (b)  beta

 

Answer:  A

 

4.  Hydrogen can form hydride ions.  Elements in group ________ typically form ions with the same charge as the hydride ion.

       (a)  1A                                                                        (c)  6A

       (b)  2A                                                                        (d)  7A

                                     (e)  3A

 

Answer:  D

 

5.  Alkenes always contain a ________________________.

       (a)  carbon-carbon double bond                                 (c)  carbon-hydrogen triple bond

       (b)  carbon-carbon single bond                                  (d)  carbon-carbon triple bond

                                     (e)  carbon-hydrogen double bond

 

Answer:  A

 

6.  The general formula for an aldehyde is:

      

Answer:  C

 

7.  The general shape of a protein is called the protein’s _____________ structure.

       (a)  secondary                                                             (c)  primary

       (b)  tertiary

 

Answer:  B

 

8.  Which of the following polysaccharides contain a linkages between the monomeric glucose molecules and is generally found in plants?

       (a)  glycogen                                                               (c)  starch

       (b)  cellulose                                                              (d)  sucrose

 

Answer:  C

 

9.  The coordination complex [Co(NH3)3Cl]Cl2 dissolves in water to produce _________ ions.

       (a)  0                                                                           (c)  2

       (b)  1                                                                           (d)  3

                                     (e)  4

 

Answer:  D

 

10.  Metallurgical processes performed in aqueous solutions are collectively called:

       (a)  hydrometallurgy                                                   (c)  electrometallurgy

       (b)  pyrometallurgy                                                     (d)  alloying

                                     (e)  roasting

 

Answer:  A

 

 

 

 

 

 

 

Part 2

 

Numerical Problems

 

Solve the following problems, keeping track of significant figures where applicable.  Please show all the work necessary to obtain your answer in order to receive partial credit for possibly wrong answers.  Generally, full credit will not be given for the correct answer without any of the work performed to obtain the answer being shown on the paper.  Each question is worth either 10 or 15 points.

 

 

11.  (10 points)   Identify the functional groups in each of the following compounds.  Some compounds may contain more than one functional group.

 

 

12.  (15 points)  One of the two stable isotopes of antimony, Sb, is antimony-123.  123Sb has an atomic mass of 122.904271 amu.  Given 1.007276 amu as the mass of a proton and 1.008665 amu as the mass of a neutron, calculate the binding energy of 123Sb in units of J/nucleon.

 

First calculate the mass defect of 123Sb with 51 protons and 72 neutrons:

Convert the mass defect to units of kg: 

Convert the mass defect into binding energy using E=mc2:

Divide by the number of nucleons to get binding energy per nucleon:

 

13.  (10 points)  In the production of iron, 3 ingredients are poured into the top of the blast furnace:  iron ore (Fe2O3, Fe3O4, and iron silicates); limestone (CaCO3(s)); and coke (Cs)).

 

(a)  What is the function of the limestone in the production of iron?

 

It decomposes to CaO and CO2 near the top.  CaO combines with the silicates to form slag.  This removes the silicates from the iron.

 

(b)  What reduces the iron oxides to iron metal?

 

Carbon monoxide, CO(g)

 

(c)  Write a balanced chemical reaction for the reduction of one of the iron oxides to iron metal:

 

Fe­2O3(s)  +  3 CO(g)  ¾¾®  2 Fe(l)  +  3 CO2(g)

 

or

 

Fe3O4(s)  +  4 CO(g)  ¾¾®  3 Fe(l)  +  4 CO2(g)

 

 

14.  (10 points)  Complete and balance the following nuclear reactions:

 

(a) 

 

The missing nuclide is

 

(b) 

 

The missing nuclide is

 

(c) 

 

The missing nuclide is

 

 

15.  (15 points)  Either give the official name for the given structure, or write the structure for the given name for the hydrocarbons below:

 

 

 

 

For 10 points extra credit:

 

Define 2 of the following 3 terms:

 

Polydentate ligand:  a ligand that can attached to a metal cation via more than one site.

 

 

 

Paramagnetic:  anything with unpaired electrons.

 

 

Zone refining:  a method of purifying silicon in which a layer of a silicon rod is melted.  The molten zone is moved along the silicon rod with the impurites staying in the molten layer and purified silicon solidifying out.