Model Answer
0 min readIntroduction
Mineralogy, a branch of geology, deals with the study of the chemistry, crystal structure, and physical (including optical) properties of minerals. Determining the chemical composition of minerals is fundamental to their identification and classification. Iron is a crucial constituent of many economically important minerals, playing a significant role in various geological processes and industrial applications. Calculating the weight percentage of iron in these minerals is a basic yet essential exercise in quantitative mineralogy, providing insights into their economic viability and geological origin. This answer will calculate the wt.% of iron in Ilmenite, Magnetite, Chromite, and Hematite, and arrange them in increasing order of iron content.
Calculating Weight Percentage of Iron in Each Mineral
The weight percentage of an element in a mineral is calculated using the following formula:
Wt.% of Element = ( (Atomic weight of Element * Number of atoms of Element in the formula) / Molecular weight of the mineral ) * 100
1. Ilmenite (FeTiO3)
Molecular weight of FeTiO3 = 56 + 48 + (3 * 16) = 152
Wt.% of Fe = ( (56 * 1) / 152 ) * 100 = 36.84%
2. Magnetite (Fe3O4)
Molecular weight of Fe3O4 = (3 * 56) + (4 * 16) = 236
Wt.% of Fe = ( (56 * 3) / 236 ) * 100 = 71.19%
3. Chromite (FeCr2O4)
Molecular weight of FeCr2O4 = 56 + (2 * 52) + (4 * 16) = 228
Wt.% of Fe = ( (56 * 1) / 228 ) * 100 = 24.56%
4. Hematite (Fe2O3)
Molecular weight of Fe2O3 = (2 * 56) + (3 * 16) = 160
Wt.% of Fe = ( (56 * 2) / 160 ) * 100 = 70.00%
Arranging Minerals in Order of Increasing Iron Content
Based on the calculated weight percentages, the minerals arranged in order of increasing iron content are:
- Chromite (24.56%)
- Ilmenite (36.84%)
- Hematite (70.00%)
- Magnetite (71.19%)
The following table summarizes the results:
| Mineral | Chemical Formula | Wt.% of Fe |
|---|---|---|
| Chromite | FeCr2O4 | 24.56% |
| Ilmenite | FeTiO3 | 36.84% |
| Hematite | Fe2O3 | 70.00% |
| Magnetite | Fe3O4 | 71.19% |
Conclusion
In conclusion, the weight percentage of iron varies significantly among these common iron-bearing minerals. Magnetite exhibits the highest iron content (71.19%), followed closely by Hematite (70.00%), while Chromite has the lowest (24.56%). Understanding these compositional differences is crucial for mineral exploration, beneficiation, and utilization in various industries. Accurate chemical analysis remains a cornerstone of geological investigations and resource management.
Answer Length
This is a comprehensive model answer for learning purposes and may exceed the word limit. In the exam, always adhere to the prescribed word count.