74. Solving a chemistry problem

3. Based on data on the temperatures of the beginning of crystallization of a two-component system:
1) build a phase diagram (melting diagram) of the system A - B;
2) mark with dots: I - liquid melt containing a % of substance A at temperature T1; II - a melt containing a % of substance A, in equilibrium with crystals of a chemical compound; III - a system consisting of a solid substance A, which is in equilibrium with a melt containing b% of substance A; IV - equilibrium of phases of the same composition; V is the equilibrium of three phases;
3) determine the composition of a stable chemical compound;
4) determine the qualitative and quantitative composition of eutectics;
5) draw all types of cooling curves possible for a given system, indicate which compositions on the fusibility diagram these curves correspond to;
6) in what phase are the systems containing c, d, e% of substance A at temperature T1? What happens to these systems if they are cooled to a temperature T2?
7) determine the number of phases and the number of conditional thermodynamic degrees of freedom of the system at the eutectic temperature and the molar content of component A 95 and 5%;
8) at what temperature will the melt containing % of substance A begin to solidify? At what temperature will it harden completely? What is the composition of the first crystals?
9) at what temperature will a system containing d% of substance A begin to melt? At what temperature will it melt completely? What is the composition of the first droplets of the melt?
10) calculate the heats of fusion of substances A and B;
11) what component and in what quantity will crystallize out of the system if 2 kg of melt containing a % of substance A is cooled from T1 to T2?

No.
option
Systems
Molar content of A, % Starting temperature
crystallization, K Molar content. A, % Temperature
start of crystallization, K

3A-KCl
B – MnCl2 0
eight
fifteen
25
34
36
38
40 923
895
865
715
745
722
735
747 50
60
65
66
75
85
100 769
731
705
701
705
925
1047

Option No. T1, K a b c d e T2, K
3 873 40 80 10 40 80 733