Geochemistry

Exercise Ia

Conversions, formulas, etc.

Due September 2, 2005

 

1.     One publication lists CaO and another lists Ca concentration in basalts.  You would like to compare these two values in terms of Ca.  How do you convert CaO to Ca?

 

2.     Same situation as in question 1 except one report lists Fe and the other Fe2O3.  Convert 2.52% Fe to %Fe2O3.

 

3.     What is the total percentage of lead in an ore containing 50% galena, 30% bournonite, and 20% tetrahedrite?

 

4.     How much hemimorphite can be formed by weathering 100 tons of sphalerite?  Assume no Zn loss during weathering.

 

5.     What is the formula of a mineral with the following composition?

 

                        Pb                    50.0%

                        Sb                    29.5%

                          S                    19.7%

 

6.     Chemical analysis of a mixture of chalcocite and covellite gives the following data.  What are the relative proportions of the two minerals?

 

Cu                    76.5%

                          S                    23.5%

 

 

7.     Some authors report Fe as FeO and others as Fe2O3.  What is the conversion factor for obtaining FeO from Fe2O3?

 

8.     a.   What is the weight percent of Ca in dolomite?

b.     What is the weight percent of Ca in calcite?

c.      What is the cation mole percent of calcium for dolomite?

d.     What is the cation mole percent of calcium for calcite?

 

9.     a.   Convert 0.15% Fe to ppm.

b.     Convert 156 ppm Na to weight percent.

 

10. a.   Convert 0.01M Ca to ppm.

b.   Convert 0.02 N H2SO4 to M and then to mg/L.