If you combine 5 grams of NaAlSi3O8 with 3 grams of CaAl2Si2O8 what is the weight fraction of albite in the resulting plagioclase? Show your work. What is the weight fraction of anorthite? Express the plagioclase composition as Anxx (by weight). 8. Plagioclase contains Na, Ca, Al, Si, and O. For phase rule treatment, what is C? Why? It would require 3-dimensions to illustrate the P-T-X variables for a 2-component system, so we simplify our diagrams by concentrating on the most important variables, typically T and X. We thus construct T-X diagrams at some specified pressure. 9. The temperature-composition (T-X) Ab-An binary phase diagram at 1 atmosphere pressure is shown on the right. If we were to heat pure anorthite at this pressure, what would be the variance (F) when it began to melt? Show your work. What variables specifically addressed by the diagram could vary intensive between the first occurrence of melt and the last bit of anorthite to disappear? What extensive variables on the diagram most obviously change during that interval? with composition at 1550oC. What is the weight fraction of An in the liquid () ? a
If you combine 5 grams of NaAlSi3O8 with 3 grams of CaAl2Si2O8 what is the weight fraction of albite in the resulting plagioclase? Show your work. What is the weight fraction of anorthite? Express the plagioclase composition as Anxx (by weight). 8. Plagioclase contains Na, Ca, Al, Si, and O. For phase rule treatment, what is C? Why? It would require 3-dimensions to illustrate the P-T-X variables for a 2-component system, so we simplify our diagrams by concentrating on the most important variables, typically T and X. We thus construct T-X diagrams at some specified pressure. 9. The temperature-composition (T-X) Ab-An binary phase diagram at 1 atmosphere pressure is shown on the right. If we were to heat pure anorthite at this pressure, what would be the variance (F) when it began to melt? Show your work. What intensive variables specifically addressed by the diagram could vary between the first occurrence of melt and the last bit of anorthite to disappear? What extensive variables on the diagram most obviously change during that interval? with composition a at 1550oC. What is the weight fraction of An in the liquid () ?
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