1. Give three examples of pure chemicals that can be purchased 
   at a grocery store.


2. Name a pure element that is used to make water pipe and 
   electrical wiring.



3. Describe what happens when sugar is heated strongly.


4. If a pure substance cannot be chemically decomposed into two 
   of more other substances, the pure substance is called 
   a/an ____________.


5. If a mixture has the same appearance as a pure substance, the 
   mixture is called a/an _____________.

6. If a material can be determined to be a mixture by visual 
   observation, the material is a/an _____________.

7. True or False: The properties of a compound are vastly 
   different from the properties of the elements into which it 
   can be decomposed. 


8. Give three examples of pure compounds.


9. Give three examples of pure elements.


10. Give three examples of solutions.


11. Give three examples of heterogeneous mixtures.


12. Give symbols for the following elements:

    sodium              chlorine
    hydrogen            iron
    carbon              oxygen
    potassium           sulfur
    nitrogen            phosphorus
    magnesium           manganese
    neon                fluorine
    silicon             aluminum
    calcium             iodine
    helium              copper
    silver              gold
    lead                mercury
    uranium             tungsten
    lithium             boron
    zinc                nickel
    chromium            bromine
    argon               barium


13. Determine whether each of the following elements is 
nonmetallic or metallic: Al, S, O, Fe, Cu, Cl, H, Na, K


14. State a fact that is true for all compounds.


15. How does the total weight of the reactants in a chemical 
reaction compare to the total weight of the products?>


16. Show how Dalton's Atomic Theory accounts for the Law of 
Conservation of Matter.



17. Write the formulae for the following:

                water
                salt
                baking soda
                sugar
                ammonia
                methane


18. Draw a picture of a water molecule.


19. The following is the molecular formula for sulfuric acid: 
H2SO4  How many hydrogen atoms, sulfur 
atoms, and oxygen atoms are contained in 1 molecule of sulfuric 
acid?  How many of each in 10 molecules of sulfuric acid?


20. If a material consists of molecules all of which are 
identical and in each molecule all the atoms are identical,
what type of material is it?


21. If a material consists of molecules all of which are 
identical and each molecule contains atoms of different elements, 
what type of material is it?


22. If a material consist of two different types of molecules 
with all the molecules randomly and uniformly mixed, what type of 
material is it?
    
    
23. If two electrically charged objects are attracted to each 
other what must be true about the nature of the charges?
    
    
24. For the following compounds, indicate whether each is 
molecular (made of molecules) or ionic (made of ions).  Hint: 
ionic compounds always contain at least one metal and one 
nonmetal.

    H2O
    NaCl
    NaHCO3
    C12H22O11
    CH4    
    CaO
    CO2
    H2SO4
    KCl
    SO2
    FeCl2

25. Balance the following reactions:

     H2   +    O2   -->     H2O

     Na   +    Cl2  -->     NaCl

     B    +    O2   -->     B2O3

     S8   +    O2   -->     SO2

     P4   +    Cl2  -->     PCl5

     Ba   +    S8   -->     BaS
    
     Al   +    CuCl2 -->    AlCl3   +   Cu

     KOH  +    H3PO4  -->   K3PO4   +    H2O


26. Write a balanced equation for the complete combustion of 
    propane, C3H8.


27. Name a device that will accomplish each of the following 
energy conversions:
    
        transform chemical energy into thermal energy
        transform chemical energy into electrical energy
        transform electrical energy into radiant energy
        transform mechanical energy into electrical energy


28. The conversion of chemical energy into electrical energy in a 
gas-fired plant is very inefficient (35% conversion) with most of 
the chemical energy ending up as waste heat.  Which of the steps 
in this energy conversion is primarily responsible for lack of 
efficiently?