Arkansas State University 
Department of Chemistry
and Physics
CHEM2004
Exam 4

CHEM2004                                                                Name_______________________

Exam 4                                                                        Fall 2006 

1.            Balance the following redox equation:                                                (10 points) 

 Fe +2  (aq)    +       Cr 2O 7 2 - (aq)  g    Fe +3  (aq)    +      Cr +3 (aq)  (acidic solution) 

2.         Write the Nernst equation for the balanced reaction in problem 1: Is the cell potential pH dependent?  Explain. (6 points)

3.         List the 5 potentially hazardous combinations and give an example for each.  (15 points)

4.         What two electronegative nonmetals are mild oxidizing agents?                (4 points)

5.         In class, the activity of the metals were categorized by their electronegativities.  Give the three classes and describe how each of these react with H2O.     (6 points)

6.         Which is the better oxidizing agent, F2 or Br2 ?  (2 points)

7.         Fill in the blank. (2 points each)

a) Name of the effect that causes current to flow when a pressure is applied

 _________________________________

b) For a spontaneous process the sign of Eo is  ___________________

c) High melting solids with a low volatility _______________________________

d) Process of mixing powders and heating to high temperatures, allowing the powders to slowly fuse into each others’ lattices ____________________________

e) solids without a regular crystalline pattern are said to be ________________________

8.         Match the class of silicate with each of the following substances. (1 point each)

_____ muscovite                                                                                         A. simple silicate 

_____ hornblende                                                                                        B.  linear silicate 

_____ zircon                                                                                                 C.  cyclic silicate 

_____ beryl                                                                                                   D.  chain silicate 

_____ talc                                                                                                      E.  polymeric sheet silicate 

_____ olivine                                                                                                  F.  three dimensional silicate 

_____ benitoite 

_____ augite 

_____ amethyst 

_____ kaolinite

9.         Give the oxide or oxoanion that best fits or describes each of the following:  (2 points each)

used to stain biological tissue  ___________________________

Portland cement ______________________________

Much of the Earth’s geochemistry depends on the chemistry of _____________________________

Type of elements added to give glass color _______________________

absorbs x-rays from color TV tubes  ________________________________

10.       Describe how glass is made.  Use the terms acidic oxide and basic oxide in your answer.  (8 points) 

11.       State the First Principle of Isomorphous Substitution and give an example. (6 points)

12.       Draw the structure of an amphibole.    (3 points)

Turn in the completed exam 3 (problems 7 – 11) and exam 4a from the old exams section on the web.  (10 points).  Must be turned in to Dr. D. by 9 am Tuesday, November 14th, 2006.