CHEM125                                                                                                      Fall, 2003

Hourly Exam # 3                                                                                             Dunnivant

 

Name (PRINTED) ____________________________________

 

The honor statement must be signed in order for your exam to be graded.

I have neither given nor received aid on this exam.  

                                                            Signature ________________________

 

 

c = 2.998 x 108 m/s  ;  h = 6.626 x 10-34 Js  :  AvogadroÕs number = 6.022 x 1023

 

 

NOTES:

Show all work for partial credit.   Significant figures will be graded throughout the exam.

 

  1. (8 pts)  How much energy does one photon of light have if it has a wavelength of 400.3 nm.

 

 

  1. (2 pts) What is the approximate range (in nm) of visible light

 

 

3.  Answer the questions below based the following diagram:

File written by Adobe Photoshop¨ 4.0
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


(10 pts)  Describe how the results of this experiment (and PlanckÕs and EinsteinÕs theories) proved the ŌClassical theoryĶ of light and energy to be wrong.  Also, what theory replaced the Classical view and what are the major advances in this theory?

 

 

  1. (5 pts)  An electron in a hydrogen atom is raised from its ground state to an n value of 5.  What is the energy involved in this transition?

 

 

  1. (10 pts)  Using the concept of SchrodingerÕs wave function and the four quantum numbers, describe the possible locations or energy levels of an electron in a hydrogen atom.  DO NOT JUST CONCENTRATE ON THE DEFINITIONS OF THE QUANTUM NUMBERS, BUT USE THEM IN YOUR DISCUSSION.  Feel free to use a computer to write your answer, BUT DO NOT CONSULT THE INTERNET!  If youÕre unclear on what IÕm asking, talk to me.

 

 

  1. (5 pts)  Give the type of orbital (such as 1s or 4d) that fits the following set of quantum numbers:

 

Quantum #s                             Answer

 

n = 5, l = 2                              ___________

 

            n = 3, l = 0                              ___________

 

 

  1. (3 pts)  Give the spectroscopic notation (noble gas abbreviation) for the following:

 

a)     an oxygen atom

 

b)    a plutonium atom

 

 

  1. (2 pts)  What spectroscopic notation numbers do the new electrons that account for the negative two charge in oxygen have?

 

 

  1. (2 pts)  Will the ionic size of

 

a cation increase or decrease?

 

an anion increase or decrease?

 

 

  1. (3 pts)  Which will have the largest radius:

 

a Na atom or a Si atom

           

a Sr atom or a Ru atom

 

 

  1. (5 pts)  We discussed the Periodic trend that atomic sizes decrease as you go from left to right.  Using the following figure, explain why ionic sizes do not follow this same trend.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


  1. ( 5 pts)  Explain/Discuss the trend of increasing or decreasing ionization energy when moving from left to right and top to bottom in the Periodic table.

 

  1. (2 pts)  The general trend of Group I metals (represented by M) reacting with water is

 

2 M  +  2 H2O    2 MOH  +  H2

 

List the Group I metals (from low to high heat) with respect to the amount of heat produced by this reactio

 

 

16.   (3 pts)  Give an example of a compound possessing

 

an ionic bond:  _____________

 

a polar covalent bond:  _______________

 

a purely covalent bond:  _______________

 

 

17.   (15 pts) Draw Lewis dot structures for the following compounds:

 

 

Carbon monoxide (CO)

 

 

Nitrate ion (NO3-)

 

 

Acetic Acid (CH3COOH)

 

 

18.   (15 pts)  Draw the dipole moment above each of the following compounds:

 

 

H

 

  Cl      C      H

     

                  H

 

 

 

      H         C         N

 

 

 

      O         C         O

 

 

 

 

 

19.   (5 pts)  Explain what types of compounds bioconcentrate and why these compounds bioconcentrate.