Remember that on a triangular phase diagram that a single point within the phase
ID: 496968 • Letter: R
Question
Remember that on a triangular phase diagram that a single point within the phase diagram represents a particular phase that combines all three components. Points on a side represent a phase that combines only two components. (A) What is the formula corresponding to point A on the diagram below? (B) The composition of a point within the diagram can be read off by measuring the distance from the point to the triangle edge following a line parallel to one of the other side. If we label the corners A, B, and C the distance to the BC edge gives the fractional amount of A, the distance to the AC edge gives the fractional amount of B, the distance to the AB edge gives the fractional amount of C, What is the formula corresponding to point B on the diagram below? In both cases, the formula should have small whole numbers.Explanation / Answer
5)
A) mass % of CaO is 50% and mass % of SiO2 is also 50%
If there is 100gm of substance then 50 gm is CaO and remaining 50 gm is SiO2
mass to moles,
CaO - 50 gm / 56.0774 g/mol = 0.8916 mol
SiO2 - 50 gm / 60.08 g/mol = 0.8322 mol
(CaO)0.89(SiO2)0.83 = (CaO)0.89/0.83 (SiO2)0.83/0.83 = CaO.SiO2 = formula of A
b) According to the description,
SiO2 - 50% ; CaO - 25% ; MgO - 25%
CaO - 0.8916 mol ; SiO2 - 25 gm / 60.08 g/mol = 0.4161 mol ;
MgO - 25gm/40.3044 g/mol = 0.6202mol
(CaO)0.42(SiO2)0.89(MgO)0.62 = (CaO)1.(SiO2)2.11.(MgO)1.47
Multiply with 2 and consider whole numbers,
B - (CaO)2(SiO2)4 (MgO)3